Leafly’s outdoor cannabis grower’s calendarPat Goggins

Growing cannabis outdoors is easy. All you need is a nice open space that gets lots of light, a water supply, good soil, and a way to cover the plants when the weather turns.

One of the most important things to know is that cannabis is dependent on a photoperiod, meaning that it changes from the vegetative to flowering stage when days start to shorten and nights get longer. You want to time things right so your plants can maximize their exposure to light during the summer before fall sets in.

Growing and harvest times here reflect ranges of time in the Northern Hemisphere. For more growing tips on specific regions, check out this guide on different climates.

(Leafly)

On the West Coast of North America, cannabis farmers in Northern California have a long season: They can put plants outside early and harvest later into the season because of the region’s relatively warm weather.

Washington state, on the other hand, will have a shorter time frame, as plants can’t be put outside until later in the season because there’s not enough sunlight yet. Harvest needs to be completed earlier, before cold weather descends on buds and makes them wet and moldy.

The Spring Equinox is a good reminder that it’s time to kick off the outdoor growing process and start germinating your seeds.

As the sun reaches up high in the sky, your cannabis will want to as well. Make sure all of your plants are outside by the Summer Solstice.

The weather will start to turn and the sun will begin descending in the sky as your plants fatten up with sweet, sticky buds. It might be tempting, but wait until around the Fall Equinox to start harvesting.

Everything should be cleaned up, dried, and curing well before the Winter Solstice. Now’s a good time to make your own cannabutter, topicals, or tinctures with all that trim from the harvest. Kick your feet up, relax, and hunker down for the cold, it’s been a long growing season!

I can’t stress enough that the time frames on this graphic are ranges of time for the Northern Hemisphere. You’ll need to adjust them based on your specific region and local weather and climate.

Be sure to keep a grow journal to track the progress of your plants. Looking back on your notes will help you learn from mistakes and maximize the quality and quantity of your buds.

Take meticulous notes on when and how you perform each step, as well as what the weather is like. Other notes can include how much water you give plants, at what intervals, and how much nutrients you give them. Pictures will also give you a better sense of how your plants look along the way.

Buy seeds

Figuring out which strains you want to grow, where to purchase them, where on your property you want to grow, and your local climate and weather can take some time and work. And once you order seeds, it can take a few weeks for them to arrive. Be sure to do your research early and get a head start so you aren’t scrambling at the last minute and miss the ideal time to grow.

Germinate/Sow seeds

It takes about 3-7 days to germinate a seed. A lot of growers will do this indoors because seeds are delicate and it’s easier to control the temperature and climate inside. But if you live in a warmer climate, by all means, start growing them from seed outside. You can also use a small greenhouse outside to keep them warm.

When you start growing your seeds depends partly on how big you want your plants to be for harvest. If you’re going for high yields, the earlier you grow your plants, the bigger they’ll be. But keep in mind that smaller plants are more manageable and easier to top and prune.

Move outdoors/Put in the ground

If germinating seeds and growing them indoors first, this is the time frame that you’d move your plants outside so they can get some serious sunlight. You want them to get at least 6 inches – 1 foot in height before putting them outside, so they’re big and strong enough to handle the weather.

Some old school gardeners will tell you to wait until after Mother’s Day to take them outside, and generally speaking, you want them in the ground by the Summer Solstice at the latest.

Top/Prune plants

Most growers top their plants a few times (two or three) throughout the season to encourage outward development and make plants bush out. It’s a good idea to give them an initial top after the plant develops five or so nodes.

Once your plants start flowering and producing buds—generally, sometime in August—you want to stop topping your plants.

Pruning and cleaning up plants is done as-needed. You want to get rid of dead leaves and lower branches that won’t get light so the plant can use that energy for producing buds in healthier branches.

Growers can clean up their plants anywhere from 1-4 times during the season, depending on how big the crop is and how much labor is needed.

Harvest

What kind of strain you have and what climate you live in will determine when to harvest your strains. Indicas typically grow stouter and bushier and there is more of a concern that their dense buds will get moldy, so they’re usually harvested on the early side of the season. Sativas are generally taller and less dense, so they usually get harvested later.

Growers in colder climates will need to finish their harvests earlier, sometimes as early as September, for fear of wet, cold weather setting in and molding out buds. Warmer climates can sometimes harvest well into November.

This post was originally published on January 15 31, 2019. It was most recently updated on May 1, 2020.

growing tipsseeds

Read More

Leafly’s cannabis homegrow

Welcome to Leafly’s cannabis homegrow! Watch as our writer Johanna Silver grows a set of marijuana plants from seed to harvest in her backyard in Northern California. Check back every week for a new post, and be sure to follow #Leaflyhomegrow on Instagram, Twitter, and Facebook.

Also, check out her book, Growing Weed in the Garden: A No-Fuss, Seed-to-Stash Guide to Outdoor Cannabis Cultivation.


There’s not a ton to do as we wait for all of our seeds to sprout. So, let’s talk for a minute about watering. Seedbeds need to be kept evenly moist through germination. “Evenly moist” is a term we throw around in gardening. It means wet but not soggy. It also means all the way through the bed. When the little babies do germinate, they have root systems about as long as the sprout is on top, which is to say, quite short. And that area needs to stay nice and moist to keep the plant alive. Here I’ve thrown in some of my radishes and other veggies with the weed seedlings.

The very best way to water is to use a shower setting—either on the end of a watering can or as the setting on a hose nozzle. I’m sorry if this is painfully obvious for you, but trust me, for others—it’s not. For example, I see a lot of misting of seeds. No dice. Won’t get the job done. You need that whole mass of seed bed to be moist. Shower setting. Nothing harder. Irrigate until you see water coming out of the bottom of the containers.

A wise farm manager once taught me that the trick when watering small plants is to keep moving; keep moving the hand that’s doing the watering and keep moving your body up and down the length of the bed. This might be overkill if you’ve just started a few seeds, but it’s good info to keep in mind if and when you start a whole bun of seeds or even plant a whole bunch of small transplants.

Check out Leafly’s growing section


The babies are sprouting! So far, I’ve got 5 out of 6 showing their green. I’m certain the others will bring up the rear quickly.

Emerging first are the cotyledon leaves—small round ones that don’t look like weed leaves—because they’re not! Cotyledon leaves are embryonic. They’re actually part of the seed. They help the plant access stored nutrients as the plant gets up and running with photosynthesis.

Any flowering plant has cotyledon leaves. Basically, any plant except those that come from spores (think: ferns) and evergreens (which produce cones) start with cotyledons, so they might look wildly familiar if you’ve ever started anything else from seed in your garden. The radish seeds I’ve got right next door to these are also sporting their cotyledons—similarly round, succulent-ish leaves.

What’s cool about cotyledon leaves is that they’re the only part of a cannabis plant that doesn’t have THC in them. It’s possible to take the leaves and mail them off to a lab for genetic testing to find out the sex of the plants long before waiting the many weeks it otherwise takes for them to start flowering to tell the difference. And since there’s no THC, you’ve not broken any laws by mailing a part of the plant.

I’ve done that in the past, using Phylos. Steep Hill is another great option. The process is fun: You mash the cotyledon onto special paper and mail it. You feel like a scientist. A few days later, you get results on who among your babies is female, and who is male. It can be especially helpful if you’ve not got the room to grow out all of your seedlings until they start flowering and reveal their sex.

I’m forgoing it this year. I’ve got time. I’ve got space (sort of). Mostly, I didn’t start a crazy amount of plants and I’m just going to give them all some time to show me who’s who and what’s what.

It’s been raining like cats and dogs around here. I’m all for it. The seedlings are in the little plastic greenhouse, so I still have to pop out there every day or two to make sure the seedbed stays moist. Who’re we kidding? I check on them like 8 times a day. I love baby seedlings. Of any kind.


cannabis, homegrow, Leafly

Hello fellow weed growers!

I grow weed in my Berkeley, California, backyard, along with veggies, fruits, herbs, and cut flowers. While info resources abound for the other crops I grow, sensible, accessible, outdoor only, garden-scale, weed-growing info is hard to come by.

So, I’m here to help. My goal is to give you regular updates (weekly at first because so much happens early on!) on how to grow weed outside, in your garden, with as little extra fuss as possible. I’ll tell you exactly how I do it.

Today I started my seeds. Could have been anytime between late March and late April. I chose today because I had a spare moment, the sun was shining, and the toddler was sleeping.

I’m growing three cultivars this year:

Freakshow

Genetics by The Humboldt Seed Company.

Chosen because it has crazy looking leaves that don’t resemble that classic cannabis leaf.

Sweet Annie

Genetics by The Humboldt Seed Company.

Chosen because it also has beautiful leaves, albeit more classically cannabis. I met this plant in person a few years back at a pheno-hunt and it looked so unique. Much more ornamental. It’s also 1:1 THC:CBD and mama could use something calming.

Cherry Pie x Chem Lemon

Seeds given to me by a friend and expert East Bay grower who has a seed collective.

Chosen because he told me it is beautiful and smells great.

If it isn’t glaringly obvious: I choose plants based on smell and looks. After all, I’m a gardener more than a weed connoisseur. Oh, but weed connoisseurs tell me my weed is legit. So, you’re good learning from me. Promise.

I’m only growing three plants total this year—two in the ground and one in a pot. The legal limit for homegrowing cannabis in California is six plants, but I want to keep some room for my veggies. I’m only starting four seeds of each cultivar. I trust that at least one of four seeds of each kind will turn out to be a female (we’ll get to sexing plants in a few weeks, but you always want to start off with 3-4 times the number of plants you’ll end up with).

I grow entirely outside. No lights, no mats. I’ll tuck them in a small plastic greenhouse to keep them safe and just a little warmer and cozier.

I start my seeds in fresh potting soil, scooped into 4-inch nursery containers I’ve amassed over the years. Seeds needn’t be planted deep—twice as deep as the seed is wide, is the rule of thumb with most seeds.

Absolutely crucial: labels. Don’t make the mistake of swearing you’ll remember. You won’t. Pro tip: Get a Sharpie Extreme. They’re the only ones that are actually permanent in outdoor conditions.

I’ll keep the soil moist through germination, which likely means a daily splash of water from a gentle setting (not “mist,” but like, “shower”) on the hose nozzle. Strong enough to drench it, but not so hard as to blast the seeds away.

In past years, I’ve pre-sprouted seeds in wet paper towel—a great thing to do if you have old seeds and want to test their viability before using unnecessary soil. I’ve also soaked them in water for 24 hours, something that can speed up germination. But, my seeds are good. I am in no rush, so straight into the soil they went.

Check back next week to see these seeds start to pop out of the soil!

Back to top

Check out Leafly’s growing section for answers to all your growing questions 

cannabis growing

Read More

How to clone a cannabis plant

Did you know that you can clone a cannabis plant? It may sound like a mad scientist experiment, but there are benefits to cloning a plant vs. growing from a seed, and cloning weed is easier than you think.

Jump to a section in this article:

Check out these additional resources for more info on cannabis clones:

There are two ways you can go about reproducing cannabis. You can grow from seed, in which you will have to acquire seeds, germinate them, sex them out, and then continue to grow them. Seeds are created through sexual reproduction, which involves crossing a male plant with a female through pollination, after which, the female will produce seeds. Breeding male and female plants will allow you to create a hybrid of the two parent plants.

You can also reproduce cannabis through cloning, otherwise known as asexual reproduction. A clone is a cutting that is genetically identical to the plant it was taken from—known as the “mother.”

Through cloning, you can create a new harvest with exact replicas of your best plants. Because the genetics are identical, a clone will give you a plant with the same characteristics as the mother, such as flavor, cannabinoid profile, yield, grow time, etc. So if you come across a specific strain or phenotype you really like, you might want to clone it to reproduce more buds that have the same effects.

With cloning, you don’t have to get new seeds every time you want to grow another plant—you just take a cutting of the old plant—and you don’t have to germinate seeds or sex them out and get rid of the males.

Not having to do these steps will save you time as well as space, both of which will help you save money.

Cannabis plant roots

Cloning cannabis is relatively easy and requires just a few key items:

  • Scissors (for cutting branches off the mother plant)
  • Razor (for trimming up cuttings)
  • Rooting setup (tray/dome/root cubes, or an auto-cloner)
  • Rooting hormone

Choose a rooting medium and setup

Common rooting mediums include rockwool, rooting cubes, or another non-soil equivalent like peat or foam. Rockwool is melted rock that has been spun into a fine thread, and it has terrific airflow and moisture retention. You can find any of these cubes at most grow stores or online.

If you’re using cubes, you’ll need to invest in a tray, a tray-cell insert, and a dome. The clones will go in the cubes, the cubes in the tray-cells, and that sits in a tray which will hold water. To keep in humidity make sure to use a dome over your tray, and you may even want to use a heat mat. For more info on this setup, check out our guide to cannabis cloning equipment.

Another method is to use an auto-cloner. These cut down on the amount of labor needed to feed and care for clones. Using aeroponics, these machines spray the bottoms of your cuttings with nutrient water at set intervals to promote root growth. They are more expensive than the traditional tray/dome/root cube setup, but they are becoming more and more popular.

Experiment to see which setup works best for you. Whichever method you choose, make sure your new clones get plenty of light—preferably 18 hours—and humidity.

How to take a cutting

Cannabis plant clones

When selecting a mother plant to clone, look for plants that are healthy, sturdy, and at least two months into the vegetative cycle. You shouldn’t take a clone off a plant once it starts flowering.

Here’s how to take a cutting:

  • Don’t fertilize mother plants for a few days leading up to taking cuttings. This will allow nitrogen to work its way out of the leaves. When you take cuttings, an excess of nitrogen in the leaves and stems will trick your clones into attempting to grow vegetation instead of diverting energy to rooting.
  • Work in a sterile environment. Use gloves and disinfect razors and scissors.
  • Look for branches that are sturdy and healthy. You want at least two nodes on the final cutting, so pick a branch that is healthy and long enough. A sturdy clone will lead to a sturdy plant.
  • Cut the clone off of the mother, cutting above the node on the mother plant. It’s OK to use scissors here; it may be hard to get a razor in the middle of the mother plant.
  • Then, using a razor, cut below the bottom node on the fresh cutting at a 45° angle to the branch. This will increase the surface area of the rooting surface, promoting faster growth.
  • Place your fresh cutting immediately into a rooting hormone. Then, put it directly into a root cube. If using an auto-cloner, you’ll put rooting hormone in the cloner after you take all your cuttings.
  • Once done taking a cutting, remove unnecessary leaves toward the bottom and clip off the tips of the remaining fan leaves on the cutting. This supports photosynthesis, helping your clones uptake nutrients and water.

Planting cannabis

Check your clones daily to make sure they have enough water by checking the bottom of the tray or auto-cloner. To increase humidity, you can spray water on the leaves with a spray bottle. If any clones die, discard them so they don’t cause mold in the rest of the clones and also to give the remaining clones more space.

Most clones will be ready to transplant into soil in 10-14 days, but some may take longer. You’ll know they’re ready when the white roots are an inch or two in length.

When getting ready to transplant, be sure to keep the environment sterile. Transplant shock can occur so be sure to use gloves when handling clones.

To transplant:

  • Put soil in your pots first.
  • Water the soil before you put in the clone, so soil doesn’t move around once the clone is in its new home.
  • Once the water has drained, with two fingers, dig out a hole 1-2 inches deep, or just enough to bury all the roots.
  • Put the clone in and gently cover with soil.

Cloning can do wonders for your cannabis garden by saving you time and money, and ensuring a genetically consistent crop. You don’t need much to get started, and if done correctly, you can have a perpetual harvest of your favorite strains year-round.

This post was originally published on June 28, 2016. It was most recently updated on February 27, 2020.

clonesgrowing tipshow to

Read More

Male vs. female cannabis: How to determine the sex of your plant

In the world of plants, reproduction can happen in a variety of ways. Monoecious plants produce two different types of flowers on the same plant, and hermaphrodite plants grow single flowers that have both male and female reproductive organs.

Cannabis is a dioecious plant, meaning male or female reproductive organs appear on different plants.

With cannabis, females are usually isolated away from males—introducing males into a garden will result in pollination, causing females to create seeds.

This is important for a breeder to achieve new genetics, but most growers remove the males to allow females to produce seedless buds, also called sinsemilla. These are the resinous buds that appear on the store shelf; they all come from female plants.

Seeded buds are generally regarded as low-quality cannabis. When seeds are present, the smoke is harsh and unpleasant.

Female genetics can be guaranteed by obtaining clones and feminized seeds. If, however, you’re working with regular seeds and are unsure of your seed’s sex, knowing how to determine the sex of your plant is vital to developing new genetics, gathering seeds, or growing sinsemilla.

Sexing cannabis plants is easy. Let’s see how to tell.

Check out these additional resources for more info on cannabis seeds:

Female cannabis pre-flowers grow as tiny bracts with hair-like stigma peeking out. Male plants produce small, round balls at the nodes. (Amy Phung/Leafly)

Cannabis plants show their sex by what grows in between their nodes (where leaves and branches extend from the stalk). Pollen sacs will develop on a male plant to spread seeds and stigma will develop on a female to catch pollen. You can see these differences weeks before they actually start serving their purposes in the reproduction cycle. These are known as “pre-flowers.”

Pre-flowers begin to develop four weeks into growth, but they may take a little longer depending on how quickly the sprouting phase occurs. By the sixth week, you should be able to find the pre-flowers and confidently determine the sex of your plant.

Pre-flowers can initially be extremely small and hard to identify with the naked eye, but you can use a magnifying glass to get a better look. Examine the nodes of the plant and look for either the early growth of small sacs on a male, or two bracts on a female, which will eventually produce the hair-like stigma.

Though there are other methods to determine what sex the plant is, examining pre-flower formation is the most reliable.

Removing males early on is important for two reasons: it frees up space in your garden so females can grow bigger and stronger, and it prevents males from pollinating females.

Hermaphrodite cannabis can express both sex organs and self-pollinate. (Amy Phung/Leafly)

When a female plant develops both male and female sex organs, it is considered a hermaphrodite. This means your cannabis plant is now capable of producing pollen that can pollinate your entire garden. “Herming out,” as some call it, is something that generally happens when a plant becomes excessively stressed. Some plant stressors include:

  • Plant damage
  • Bad weather
  • Disease
  • Nutrient deficiencies

There are two types of hermaphrodite plants:

  • A plant that develops both buds and pollen sacs
  • A plant that produces anthers, commonly referred to as “bananas” due to their appearance

While both result in pollen production, true hermaphrodites produce sacs that need to rupture, while anthers are exposed, pollen-producing stamen.

Because this occurs when cannabis is under stress, it’s important to monitor plants after they have been exposed to stressors—indoors: high temperatures or light leaks are often the cause; outdoors: a snapped branch might be repaired and then turn into a hermaphrodite.

The other primary cause of hermaphrodite plants lies in the plant’s genetics. A plant with poor genetics or a history of hermaphrodite development should be avoided to protect your garden. If you notice any pollen sacs or anthers at any point, remove the plant from your garden immediately to prevent pollination of female plants.

If you’re interested in pollinating portions of your crop, remember that pollen is extremely potent and very good at traveling. Keep your males intended for pollination far from your garden space and work carefully with that pollen.

This post was originally published on September 19, 2017. It was most recently updated on February 11, 2020.

flowergrowing tipsscience

Read More

Cannabis seeds 101: A guide for growers

Cannabis is grown from one of two sources: a seed or a clone. Seeds carry genetic information from two parent plants that can be expressed in numerous different combinations, some like the mother, some like the father, and many presenting various traits from both. Generally, commercial cannabis producers will plant many seeds of one strain and choose the best plant. They will then take clones from that individual plant to get consistent genetics for mass production.

But for the typical homegrower, it may be easier to obtain seeds rather than clones. Growing from seed can produce a stronger plant with more solid genetics. Read on for more info on cannabis seeds.

Check out these additional resources for more info on cannabis seeds:

Jump to a section in this article:

Cannabis can be either male or female—also called “dioecious”—but only females produce the buds we all know and love. However, for reproduction, the flower of a female plant must be pollinated by a male plant, after which the female flower produces seeds. Once the seeds are mature, the female plant begins to die, and seeds are either dropped to the ground where they germinate and grow into new cannabis plants the next spring, or they are harvested for processing into hemp seed oil, food products, or to be sown to become the next generation of plants.

To get the buds you find in medical and recreational stores, female cannabis plants are grown in an environment without males—or the males are removed from the area before they release pollen—so that they don’t pollinate and create seeds. This high-potency marijuana is traditionally known as “sinsemilla,” meaning “seedless.”

Some varieties of cannabis can produce male parts alongside female flowers on the same plant, especially if exposed to environmental stressors. These plants are known as hermaphrodites, and sometimes they can self-pollinate to create seeds.

marijuana seeds in wooden bowl

Feminized cannabis seeds will produce only female plants for getting buds, so there is no need to remove males or worry about the plants getting pollinated. Feminized seeds are produced by causing the monoecious, or hermaphrodite condition in a female cannabis plant. The resulting seeds are nearly identical to the self-pollinated—or “selfed”—female parent, as only one set of genes is present.

This is sometimes referred to as “cloning by seed” and will not produce any male plants. This is achieved through several methods:

  • By spraying the plant with a solution of colloidal silver, a liquid containing tiny particles of silver
  • Through a method known as rodelization, in which a female plant pushed past maturity can pollinate another female
  • Spraying seeds with gibberellic acid, a hormone that triggers germination (this is much less common)

Most experienced growers will not use feminized seeds because they only contain one set of genes, and these should never be used for breeding purposes.

Check out Leafly’s Growing section for more on how to grow cannabis 

Most cannabis plants begin flowering when the amount of light they are exposed to each day is reduced to about 12 hours. This mimics the sun going down in the sky as the season turns to autumn, causing plants to produce buds regardless of size or age. However, a species of the plant, called Cannabis ruderalis, which developed in extreme northern conditions without much sunlight, will begin flowering once the plant reaches a certain age—they automatically start flowering regardless of the amount of light they receive, hence the term “autoflower.”

Some breeders have crossbred the low-THC ruderalis with other more potent varieties to create autoflower strains that start blooming as soon as they reach maturity. These can be easier to maintain and can be especially great in northern climates where summers are short and cold and wet weather comes early in the fall.

Autoflower strains can be started in early spring and will flower during the longest days of summer to take advantage of the highest quality light available. Growers can fit in multiple autoflower harvests in the span of a regular harvest. One drawback, though: Autoflower strains are known for being less potent.

weed seeds in wooden spoon on hemp doily

Cannabidiol, or CBD, is one of the chemical components—known collectively as cannabinoids—found in the cannabis plant. Lately, much has been made of the potential benefits of CBD for treating the symptoms of many diseases and conditions. Over the years, humans have selected plants for high-THC content, making cannabis with high levels of CBD rare. The genetic pathways through which THC is synthesized by the plant are different than those for CBD production.

Cannabis used for hemp production has been selected for other traits, including a low THC content, so as to comply with the 2018 Farm Bill. Consequently, many varieties of hemp produce significant quantities of CBD. As interest in CBD as a medicine has grown, many breeders have been crossing high-CBD hemp with cannabis. These strains have little or no THC, 1:1 ratios of THC and CBD, or some have a high-THC content along with significant amounts of CBD (3% or more).

Seeds for these varieties are now widely available online and through dispensaries. It should be noted, however, that any plant grown from these seeds is not guaranteed to produce high levels of CBD, as it takes many years to create a seed line that produces consistent results. A grower looking to produce cannabis with a certain THC to CBD ratio will need to grow from a tested and proven clone or seeds.

The most important factor in seed quality is genetics—to grow quality cannabis, you need good genetics. Some less scrupulous breeders will simply cross a nice female with a random male and sell the resulting seeds. A good breeder will take time to cross and backcross plants to stabilize the most desirable traits, while still producing an array of different phenotypes.

Seeds must also be allowed to fully mature before harvest. They also must be properly stored so they don’t acquire mold or other pathogens that can spoil them. Seeds should be stored in a cool, dark place and used within 16 months, or frozen for future use.

Really dedicated breeders have worked for years to create inbred lines, or IBLs, that will produce plants with very little noticeable difference. IBLs represent only a small fraction of cannabis seeds on the market, as they are generally used by breeders and not by producers.

Cannabis seeds can be found on numerous online seedbanks, but note that it is illegal to bring seeds into the US and Customs will seize any cannabis seeds that they find in packages or on a person. In legal and medical states, you may purchase seeds at a dispensary.

Learn more about how to buy cannabis seeds, the legality of doing so, and costs in our Guide to buying cannabis seeds.

This post was originally published on April 2, 2016. It was most recently updated on February 5, 2020.

geneticsgrowing tipsseeds

Read More

Stages of the marijuana plant growth cycle

Cannabis plants, like all living things, go through a series of stages as they grow and mature. If you’re interested in cultivating cannabis, it’s especially important to understand the changes a plant undergoes during its life cycle, as each stage of growth requires different care.

Different stages call for different amounts of light, nutrients, and water. They also help us decide when to prune and train the plants. Determining a plant’s sex and overall health rely on stages of growth as well.

Generally speaking, it takes anywhere from 14-32 weeks, or about 4-8 months, to grow a weed plant.

The biggest variability in how long a marijuana plant takes to grow will happen in the vegetative cycle—if you’re growing indoors, you can force it to flower after only a few weeks when it is small, or after several weeks when it is big. If you’re growing outdoors, you’re at the whim of the seasons and will have to wait until fall to harvest. The plant will develop buds in the last 8-11 weeks.

The life cycle of cannabis can be broken down into four primary stages from seed to harvest:

  • Germination (5-10 days)
  • Seedling (2-3 weeks)
  • Vegetative (3-16 weeks)
  • Flowering (8-11 weeks)

Light cycle: 18 hours of light

(Elysse Feigenblatt/Leafly)

The first stage of life for a cannabis plant begins with the seed. At this point, your cannabis plant is dormant, patiently waiting for water to bring it to life.

You can observe the quality of the seed by its color and texture. The seed should feel hard and dry, and be light- to dark-brown in color. An undeveloped seed is generally squishy and green or white in color and likely won’t germinate.

To begin growing from a seed, learn more about germination here. This stage can take anywhere between 5-10 days.

Once your seed has popped, it’s ready to be placed in its growing medium. The tap root will drive down while the stem of the seedling will grow upward. Two rounded cotyledon leaves will grow out from the stem as the plant unfolds from the protective casing of the seed. These initial leaves are responsible for taking in sunlight needed for the plant to become healthy and stable.

As the roots develop, you will begin to see the first iconic fan leaves grow, at which point your cannabis plant can be considered a seedling.           

Light cycle: 18 hours of light

(Elysse Feigenblatt/Leafly)

When your plant becomes a seedling, you’ll notice it developing more of the traditional cannabis leaves. As a sprout, the seed will initially produce leaves with only one ridged blade. Once new growth develops, the leaves will develop more blades (1, 3, 5, 7, etc.). A mature cannabis plant will have between 5-7 blades per leaf, but some plants may have more.

Cannabis plants are considered seedlings until they begin to develop leaves with the full number of blades on new fan leaves. A healthy seedling should be a vibrant green color. Be very careful to not overwater the plant in its seedling stage—its roots are so small, it doesn’t need much water to thrive.

At this stage, the plant is vulnerable to disease and mold. Keep its environment clean and monitor excess moisture.

Light cycle: 18 hours of light

(Elysse Feigenblatt/Leafly)

The vegetative stage of cannabis is where the plant’s growth truly takes off. At this point, you’ve transplanted your plant into a larger pot, and the roots and foliage are developing rapidly. This is also the time to begin topping or training your plants.

Spacing between the nodes should represent the type of cannabis you are growing. Indica plants tend to be short and dense, while sativas grow lanky and more open in foliage.

Be mindful to increase your watering as the plant develops. When it’s young, your plant will need water close to the stalk, but as it grows the roots will also grow outward, so start watering further away from the stalk so the roots can stretch out and absorb water more efficiently.

Vegetative plants appreciate healthy soil with nutrients. Feed them with a higher level of nitrogen at this stage.

Light cycle: 12 hours of light

(Elysse Feigenblatt/Leafly)

The flowering stage is the final stage of growth for a cannabis plant. Flowering occurs naturally when the plant receives less than 12 hours of light a day as the summer days shorten, or as the indoor light cycle is shortened. It is in this stage that resinous buds develop and your hard work will be realized.

If you need to determine the sex of your plants (to discard the males), they will start showing their sex organs a couple weeks into the flowering stage. It’s imperative to separate the males so they don’t pollenate the flowering females.

There are a number of changes to consider once your plant goes from its vegetative stage to flowering:

  • Your plants shouldn’t be pruned after three weeks into the flowering stage, as it can upset the hormones of the plant.
  • Plants should be trellised so that buds will be supported as they develop.
  • Consider feeding plants with blooming nutrients.

What week of flowering do buds grow the most?

Buds typically grow the most toward the end of the flowering cycle, around week 6-7. You probably won’t notice much budding out at the beginning of flower, and it will slow down toward the end of the cycle, when buds become fully formed.

This post was originally published on July 18, 2017. It was most recently updated on January 17, 2020.

Once the buds have reached full maturation, it’s time to harvest.

flowergrowing tipsharvesting

Read More

Bigger isn’t better: The case for growing small marijuana plants

We’re not going to delve into other matters where this might be up for debate, but when it comes to cannabis, bigger doesn’t mean better. Sure, giant weed plants look really cool. If nothing else, it’s ridiculously impressive that a warm season annual can go from seed to tree-sized in a matter of months. We get it.

But when it comes to the actual growing, drying, flavor, and quality of your crop, don’t be suckered into thinking that size is everything. In fact, we have solid reasons to encourage you to embrace smaller plants in your garden.

No matter the size, your neighbors might be able to smell the goods from over the fence. But you’ll keep your garden much less conspicuous by growing plants on the smaller side. While weed cultivation might be legal in your state, we’re still operating in a grey area due to federal illegality.

If someone’s got a vendetta against you, you’re just better off not having weed plants towering above fences and in plain sight. And besides revenge seekers, there are people who might be tempted to steal your crop if you’re making it too easy for them.

The best method of pest control always starts with you giving your plants a once over. That’s quite easy to do when plants are on the smaller side. You can reach up or kneel down, walk around your plant, and give every leaf and bud an inspection, usually without breaking a sweat or taking all day.

Things get a little more complicated when you need a ladder to do the same thing. Not only do you open the door to injury from falling, but it’ll take much more time when you’ve grown giant plants. You’ll likely skip the task entirely, opening the door for pest problems to get out of control.

Massive buds definitely look cool, but it can be a headache to try and dry them properly. A tasty, usable crop depends on buds drying evenly from the outside in and inside out. This is a much more reasonable task if buds are a manageable size. Once they feel dry from the outside, a few days of burping them in a storage vessel will suck out the remaining moisture.

Bigger buds are more difficult. Even when you think buds are dry on the outside, they might be packing quite a punch of moisture on the inside. Not only will curing be much more of an artform and take much longer, you’re much likelier to end up with mold problems.

If you’re not sold yet, this one will get you: The Emerald Cup judges often hand out awards to buds coming from plants that yield less than two pounds. Simply put, smaller plants can produce better tasting weed.

Think about it: A plant’s goal in life is to reproduce. If it’s stressed in any way, it abandons unnecessary tasks (like packing on extra foliage) and focuses everything on reproduction. That’s why you hear so much about mouthwatering dry-farmed tomatoes or grapes. The harvest might be smaller, both in fruit size and yield, but the taste is unbeatable, as stressed out plants pour everything they’ve got into their fruit, flowers, or seeds.

In the case of weed, that means stickier buds loaded with terpenes and packed with cannabinoids. Don’t take our word for it—Happy Dreams Farm, Eel River Farms, and High Water Farm are just a few of the Humboldt-area spots having great success with dry-farmed weed. Their plants are itty bitty and tasty as hell.

Not shooting for massive weed also bodes well for the environment as well as your pocketbook. You can skip the heavy doses of fertilizers in the false thinking that bigger weed yields tastier plants. What you want to do is a lot simpler and a lot less expensive.

When you first plant your weed outdoors, make sure the soil is amended with plenty of quality, finished compost. Truth be told, that’s likely all your weed needs for the growing season. It’ll be just enough to get the plant growing nicely, and not too much nourishment for the plant to get lazy about flavor.

cannabis growing

Read More

Is a cannabis cultivar the same as a strain?

As a longtime gardener, I was so delighted by cannabis the first time I included it in my garden. It’s unlike anything I’ve ever grown—it’s the only dioecious plant that needs me to sort males from females, its smells are fantastic and pungent, and its stickiness is so unique (and sort of annoying).

But there are a few other, less fortunate things, that make it unlike other crops, including some inaccurate terminology used by growers and consumers alike. While we’re finally starting to accept that indica and sativa are unreliable labels for categorizing plants, my biggest beef is with the use of the term “strain,” when what is really meant is “cultivar.”

Many cannabis enthusiasts are eager for normalization of the plant they love so much, and I believe that using accurate lingo to talk about the plant would go a long way in that effort.

“Cultivar” is short for “cultivated variety.” This is a horticultural category (as opposed to a taxonomic one) to describe a plant that’s been selected and improved upon by humans. It can be a hybrid (either intentional or not), or selected from the wild, brought under cultivation, and distinct enough to warrant a naming. No matter the origin, it’s something that’s been touched by the human hand through selection.

In writing, cultivars always appear in single quotes, non-italicized, following the genus and species, like this:

  • Cercis canadensis ‘Forest Pansy’
  • Rosmarinus officinalis ‘Tuscan Blue’
  • Festuca glauca ‘Elijah Blue’

The International Cultivation Registry Authority is responsible for the registration of all cultivars. The system is voluntary, focused on making sure cultivar names are distinct. It should be noted that cultivar registration is unrelated to Intellectual Property rights. Those sorts of legal rights must be sought through plant protection programs, patents, and trademarks, which are an entirely different ballgame.

It should be noted: offspring of cultivars are all genetically identical replicas, reproduced by cloning or vegetative cuts. For a cultivar to come from seed, a breeder needs to go through several generations of backcrossing for a reliably stable offspring.

Strain is the term most often used in microbiology and virology. It refers to a genetic variant or subtype within a microorganism. Think: flu strain.

The term is not often used to describe plants. It does sometimes show up in breeding, but mostly as it relates to genetic modification. If genes of a wheat plant are altered, the offspring of that modified plant might be deemed a strain.

Subspecies

Like genus and species, subspecies is a taxonomic rank, just below species. Subspecies are geographically isolated from other members of the species in a habitat. Although it’s genetically possible for the subspecies to interbreed with other members of the species, it doesn’t happen in nature due to the isolation. Because of that sequestration, subspecies can take on different characteristics from other members of the same species.

Some examples include:

  • Euphorbia characias ssp. characias (Mediterranean spurge frond from Portugal to Crete)
  • Euphorbia characias ssp. wulfenii (Mediterranean spurge found from Southern France to Anatolia)

Variety

Just like genus or species, variety is a taxonomic rank, more specific yet than subspecies. A variety is a form of a plant that’s different from the rest of the species in habitat. Think: a usually purple-flowered vine that also produces some rogue flowers in white.

Here’s the real rub with varieties: Gardeners have a tendency to use the terms “cultivar” and “variety” interchangeably. I’m super-duper guilty of this one. But they’re not the same. Unlike cultivars, varieties aren’t the results of human-initiated breeding. They’re 100% found in nature.

Some examples include:

  • Acer palmatum var. atropupureum (Purple Japanese maple)
  • Cercis canadensis var. alba (While flowering redbud)

Landrace

Not a taxonomic rank, this refers to domesticated, locally adapted populations. They’re impacted by both human selection as well as the natural environment. While a landrace population might look relatively uniform, we can generally think of them as rich genetic reservoirs, full of the building blocks for modern breeding programs.

They’re also, more and more, a thing of the past. We think of landrace populations as being largely pastoral in nature, maintained in rural regions by more traditional farming practices.

What we call “strains” should absolutely be called “cultivars.” These are cultivated varieties, hybridized and bred by humans. The clones you buy are genetic replicas of their parent, and any seeds you buy should hopefully have been properly stabilized and come true to their namesake.

Where it gets a little tricky is that there is no accountability or oversite of cannabis cultivar names. So, one clone or seed of “OG Kush” might come true to the parent, but it also might be totally different from someone else’s “OG Kush.”

What we call “landrace” is permissible when we talk about populations that were grown in isolation. A few examples that come to mind are Lamb’s Bread from Jamaica and Hindu Kush from the Middle East.

As for “indica” and “sativa”—it’s really time to let these go. Some people believe them to be historical subspecies of the plant, having evolved in different parts of the world, but given that these populations were always under human cultivation, I find “landrace” a much better term for regional populations.

Perhaps we can think of wild, uncultivated populations, like ruderalis, as a subspecies. But indica and sativa? They are all but outdated terms, used in recent times to describe feelings of the high rather than descriptors of the plant and its origins, but even then, they are inaccurate.

cultivationGrowingstrains

Read More

Does cloning ruin cannabis strains over time?

If you’re a cannabis enthusiast or familiar with the basic principles of botany, you’ll know that cannabis plants come from two sources: seeds and clones. One of the enduring debates among cannabis growers is the merits of growing from seeds versus cultivating from clones.

Seeds are created by sexual propagation and contain genes from both parents, rendering the seed—and the plant the seed grows into—genetically unique.

Cannabis clones are cuttings taken from a healthy female—called a mother plant—that has been grown from seed or is itself a clone. So cuttings can be taken from clones, or clones of clones, ad infinitum.

After a cutting of a growing branch is taken, it’s ideally dipped in a hormone medium and then roots out. Through this form of asexual reproduction, identical cannabis plants can be grown abundantly and for free for successive generations. Or can they?

Cannabis cloning represents an incontestably straightforward way of getting identical cannabis. What’s more, it’s currently the most dominant method of cultivating cannabis. In a commercial context where consumers demand consistency, it’s a gift.

However, there are murmurs among seasoned growers that clones lose potency over time. Some think it’s the phenomenon of clonal degradation: the notion that cannabis clones drift away from the mother plant’s genes over subsequent generations, resulting in weaker plants that yield less and become more susceptible to pests and fungi.

Clonal degradation, or genetic drift as it is sometimes called (though this term is debatable), is fiercely contested in the world of weed: some maintain it is a myth, while others insist it’s a real phenomenon. Cannabis chat rooms are saturated with arguments over how clonal decay occurs, with some blaming mutation in clones, while others point to cellular degradation when they become “cloned out.”

Let’s unpack genetic drift by briefly revisiting some of the basics of high school bio.

Cloned cuttings can’t change their genetic imprint because a clone is an exact genetic replica of the mother plant. A clone is even the same cellular age as the mother plant—a one-week-old clone taken from a two-month-old mother is actually two months old.

Genetic variation comes from sexual reproduction, i.e., with seeds. While genetic mutations can occur as a result of growth, it doesn’t mean that the gene pool of cannabis clones dramatically changes from generation to generation.

But the same clones subjected to different environments often look and grow differently. An under-fertilized clone in a low-humidity environment will grow with less vigor than its sister receiving perfect fertilization and humidity in a grow room across town. Environment plays a critical role in the growth and health of a cannabis clone.

The field of epigenetics offers valuable insights for understanding how cannabis clones can appear to lose potency. Epigenetics refers to outside stimuli, or modifications, that can turn genes on or off. It’s not that there is an alteration of the genetic code in the clone; rather, environmental factors modify its genetic potential and expression.

“Epigenetic impacts on clone health over time are very significant. Without proper mineral nutrition and biological health, the vigor of a clone will diminish over time as it continually is replicated, thus reducing its viability,” said Russell Pace III, President of the Cannabis Horticultural Association.

Epigenetics provides us with a more nuanced understanding of the nature versus nurture paradox. Genes load the gun, as the saying goes, but the environment pulls the trigger.

So now that we know successive generations of cannabis clones aren’t genetically inferior in some way, what are some of the environmental factors or stressors that affect the growth of clones?

Environmental elements that are essential to optimizing clone potency include the maintenance of appropriate levels of light, humidity, soil nutrients, and water. Stressors that should be avoided include over or underwatering, over or underfeeding, incorrect soil pH, and inconsistency with light cycles during the vegetative and flowering cycles. Pesticides can be another stressor that can damage plants when misapplied or applied overzealously.

Taproots: they’re important

Another inevitable contributor to clonal decay that isn’t environmental may be the lack of a taproot. Cannabis grown from seed has a taproot—a central root which is sent deep into the soil from which subsidiary roots grow.

When a cutting is taken from a cannabis plant, the cutting must develop a tangle of roots to funnel up moisture and nutrients. Clones lack a taproot and therefore are structurally (not genetically) distinct to cannabis grown from seed.

“The lack of a taproot definitely affects the vigor of a cloned plant when compared to the growth rate of a seed plant,” said Pace. “A seed plant will be infinitely more robust and have faster growth rates in most cases.”

Cleanliness is critical to clone success

The mere act of taking a cutting from the mother plant also introduces a host of potential problems. Aside from inflicting transplant shock on the clone, the cut part creates an easy passage for pathogens such as bacteria, viruses, and fungi to weave their way in, causing infection.

“Basically, a clone infected with a virus is like a dud where it grows slow and really doesn’t produce very well,” said Pace.

Growers who scrupulously sterilize cloning equipment and use proper techniques will have greater success cloning without issue. When every care is taken to ensure that the cutting is taken as gently as possible, and appropriate rooting and hormone mediums are used, the clone is more likely to extend a robust rooting system and grow strong and healthy.

That said, however, cannabis horticulturist Jorge Cervantes points out that genetic mutations can and do occur in clone populations as they grow and can be passed on through cuttings. While peer-reviewed studies exploring the intricacies of cannabis botany are still few and far between, there is research to suggest that phenotypic variation—that’s variation in physical characteristics—in plant cuttings is due to sporadic mutations in the DNA sequences.

A theory known as Muller’s ratchet argues that clone populations are doomed to accumulate increasing numbers of harmful mutations, which inhibit the plant’s ability to grow and thrive. Some interpret it as nature’s way of showing a preference for sexual reproduction in plant populations.

What’s more, telomeres may also play a role in clonal decay. Telomeres are protective caps at the ends of chromosomes that ensure DNA is copied accurately when it divides. When telomeres are stressed or damaged, the very end of the DNA strand doesn’t make it into the new copy, which results in a loss of vital genetic information.

It can be helpful to conceptualize this process like a photocopier cutting off the last line of text from a page each time it is copied—analogously, DNA strands may become shorter with every cell division.

The result is that plants lose their competence to undergo normal cell division, and healthy growth becomes decelerated or arrested. While we still don’t know a lot about how telomeres work in cloned plants, or more specifically in cloned cannabis plants, we do know that telomere shortening can be exacerbated by environmental stressors and physiological processes such as aging.

And it’s important to only clone from mother plants in a vegetative state as this study shows that age may play a role in clonal genetic mutations. Older mothers that have already been through flowering cycles are not an optimal source for cuttings because the stress of these processes compromises their genetic integrity.

Ultimately, there is a host of factors that may contribute to clonal decay. While the control of some elements is out of our hands, clonal degradation can be somewhat avoided with proper care, technique, and management of clones. Take clones from robust young mothers using sterile equipment, provide them with the best possible environment, and there’s no reason they won’t thrive for generations.

What’s most promising, according to Pace, is that even damaged or weak clones can be nursed back to health with the right growing conditions such as healthy soil.

“I think this is a most promising type of immunotherapy, so to speak,” says Pace. “Healthy soil biology can act as epigenetic gene therapy for plants. The grower attempts to create optimal environments loaded with beneficial biology and a well balanced soil chemistry.”

This epigenetic gene therapy, of sorts, can boost the innate immune systems of clones. “It essentially allows them to express their highest level of epigenetic potential. It’s really fascinating and something I’ve witnessed first-hand,” said Pace.

clonesgeneticsGrowing

Read More

How to regulate temperature and humidity in your indoor marijuana grow

Cannabis, like all plants, prefers certain environmental conditions in order to thrive. One of the major benefits of cultivating it indoors is that growers have the ability to manipulate their environments to suit the needs of the plants. Temperature, humidity, light intensity, and airflow are all factors that will need to be monitored and regulated in order to keep cannabis healthy through its different phases.

Cannabis is a resilient plant that can survive under a range of conditions. However, for the most part, it prefers to be kept under the following conditions in each growth stage for optimal health:

  • Seedlings/clones: 75-85°F (with lights on), ~70% relative humidity
  • Vegetative growth: 70-85°F, ~ 40-60% relative humidity
  • Flowering: 65-80°F, ~40-50% relative humidity

To understanding how to regulate your indoor environment, equip yourself with these cheap and easy-to-use tools to take measurements. You’ll need:

  • Thermometer: A basic one will allow you to measure how warm or cool the environment is inside your garden.
  • Hygrometer: This measures humidity, or more specifically, water vapor content in the air.
  • Infrared thermometer, or IR thermometer (optional): IR thermometers use a detection device called a thermopile to measure surface temperatures. Although not necessary, these are helpful in finding out leaf temperatures, which will give you an extra layer of knowledge on how to properly regulate environmental conditions.

Now that you have the tools to take correct environmental measurements, you can begin to make actual changes. The two factors you need to control to dial in the environment are temperature and humidity.

Inevitably, there will be fluctuations of these two in your garden. These fluctuations can occur both throughout a grow space as well as within pockets inside a given room. They can also occur at different points within a given day or throughout a season as conditions change in the environment outside your grow space.

Regulating Temperature

This can be achieved by manipulating four factors.

Light. The largest impact on the temperature in your garden is the type of light you use and how much heat it generates. Different grow lights will give off different heat signatures and depending on the size of your indoor space, room temperature can vary. Hot lights such as metal halides (MH), high-intensity discharges (HIDs), and compact fluorescent lamps (CFLs) will produce much more heat in a small space than LEDs. However, even LEDs produce some heat.

Additionally, lights can be raised or lowered to change temperature at the canopy level.

Airflow. Controlling airflow is the best way to move hot and cool air throughout your grow space. Airflow can remove warm air produced from lights out of the garden and bring fresh cool air into it when needed. Airflow can also help exchange air throughout your canopy, cooling leaves in the process.

Fans and ducts help regulate airflow—fans push air where it is needed and ducting can direct air into and out of your grow space, as well as to specific areas.

Inline fans pull cool air from outside of the garden inside, stationary and oscillating fans push fresh air throughout the garden, and ducted hoods can remove hot air produced by lights away from the canopy.

Air conditioners. In order to rapidly cool a grow environment that is too warm when light and airflow manipulation aren’t doing enough, you may need to bring in an air conditioner to cool the overall temperature of your grow space.

Heaters. Some gardens may actually require warm air, especially during times when lights are off and not generating heat. This is where a heater can come into play.

Regulating Humidity

Humidity is the measure of water vapor in the air. There are four things you can use to help control it.

  • Dehumidifiers: Dehumidifiers remove moisture from the air. These units are used much more frequently in indoor grow spaces because plants in a confined space tend to create moisture, and the space will usually feel warm and humid.
  • Humidifiers: A humidifier can produce a constant flow of water vapor for an indoor garden. They use cool water to create a mist that disperses throughout the space and increases moisture levels.
  • Airflow: As with regulating temperature, regulating airflow will allow you to move moisture in and out of your grow space and control humidity. Simply opening up a grow space, i.e., opening the door to your grow room or tent, can bring down the humidity level.
  • Water: In the absence of a humidifier, you can mist plants with a spray bottle to create extra moisture.

Balancing the system

It can be a tricky getting the right balance of temperature and humidity because they affect each other—turning up your dehumidifier will lower the humidity of your grow space, but it will also increase the temperature of the area. This in turn may require you to turn on an AC unit—everything’s connected!

Depending on how severe the seasons are in your area, you can schedule your light cycles depending on the temperature outside—in the summer, the heat outside your grow and the heat inside generated by the lights might be too much for your plants, so you may have to turn the lights on at night when it’s cooler outside. The same is true for winter—you may have to shift the light cycle to nighttime so that your plants don’t get too cold.

For growers who have a little extra money to spend and want full control over their indoor garden, environmental controllers will allow you to automate the process. These devices are essential for monitoring and controlling your environment if you’re away from your garden for any amount of time.

Controllers monitor conditions within your garden and are connected to devices necessary to manipulate those conditions. You can connect a controller to fans, dehumidifiers, humidifiers, heaters, or air conditioners, and set thresholds whereby each device will power on and off based on your ideal environmental settings. Some units run autonomously, making changes based on set parameters, while others allow you to control each element via an app on a phone, tablet, or computer.

Your average homegrower doesn’t necessarily need to know this method for regulating your environment, but if you want to get really scientific about it, here goes.

Once you familiarize yourself with how to use a thermometer, hygrometer, and IR thermometer, you can go a step further and learn how to extrapolate data from them to properly correct environmental conditions in your garden. You can do this by understanding the Vapor pressure deficit (VPD) of your garden.

VPD is the best metric for measuring and mitigating indoor grow conditions because it provides a stable unit of measurement among the constant shifts in a garden’s temperature and humidity.

Plants primarily absorb water in order to stay cool. The majority of that water comes in through the roots and out the leaves through tiny pores—called stomata—in a process called transpiration.

Inside of a healthy leaf, relative humidity is around 100%—this means that gasses within the leaf are 100% saturated with moisture, creating pressure (saturated vapor pressure, to be exact).

The stomata on a leaf’s surface act as valves for moisture, transpiring vapor quicker when hot and dry, and slower when humid. Plants like to have their stomata open so that photosynthesis can occur. When proper conditions within the plant are not met, plants can close their stomata in an effort to keep water in, thereby halting photosynthesis.

To measure VPD, you need these readings:

  • Air temperature
  • Humidity
  • Leaf temperature

Without an IR thermometer, you can still get a leaf temperature estimate by taking a temperature reading at the canopy level with a standard thermometer.

There are plenty of VPD calculators and charts available online that can help you figure out this metric for your garden. You will simply need to input the three metrics above into the calculator or use a chart to get an estimate.

Cannabis requires the following VPD in these phases to thrive:

  • Propagation and early veg: 0.4 – 0.8 kPa
  • Late veg and early flower: 0.8 – 1.2 kPa
  • Mid-flower to late flower: 1.2 – 1.6 kPa

Using VPD to measure your garden conditions will allow you to easily make environmental changes based on where your conditions sit on the chart. Making environmental changes based on temperature or humidity alone won’t necessarily look at the whole picture of plant health as using VPD does, even though it may be more complicated to determine.

cannabis growingGrowinghumidity

Read More

How to choose a cannabis cultivar for your homegrow

Growing

November 19, 2019

(Artem Cherednik/iStock)

Because of 100ish years of prohibition, limited record-keeping, and a lack of well-quantified data, any list of cultivars claiming they are best for this, that, or the other, is totally subjective. How then is one supposed to choose from the many hundreds of cultivars of weed out there when looking to start growing yourself?

While we refuse to drum up our own list of specific cultivars, we instead offer some guidance to help you choose for yourself.

We know what you’re thinking–if you live somewhere hot with long summers, plant a sativa, as those evolved closer to equatorial climates. And if you live anywhere with a shorter growing season, reach for an indica, as those hail from harsher northern climates.

Here’s the thing–widespread hybridization means that there’s really no such thing as an indica or sativa anymore. What you get is going to be a hybrid, period.

What you will no doubt be presented with in any cultivar description is what it will do to you. Proceed with caution: Because of everyone’s individual brain and body chemistry, these descriptions don’t necessarily apply to everyone. One person’s couch lock is another person’s dance party. Truthfully, depending on the set and setting, your couch lock on one day might be your dance party on another.

We say: Go for it. Especially if you’re going to grow your own, you’re going to be smelling a lot of this plant. Why not have it be equal parts gardening and aromatherapy?

Cultivars often give a hint of smell in their name, indicating if they’re on the fruitier side (Mango, Blueberry, Orange Cookies), skunkier side (Island Sweet Skunk), earthier side (Earth OG), or gassy side (Sour Diesel). Not only may these terpenes impact your high, they most certainly surround you as your plants grow.

Again: Go for it. Let’s face it–a lot of weed looks similar once it’s dried. Why not have a little fun with color in the garden? Certain cultivars turn intensely purple, especially as cooler fall temperatures approach. Others have brightly-colored pistils–a real delight when flowering starts.

How to find cultivars with colors? Look for clues in their names. Anything with purple (Granddaddy Purple) or blue (Blue Dream) in its name likely has some color during the growing season.

Given that so much of cannabis cultivation is a gamble and everything’s a hybrid, we totally condone choosing based on name–it’s sort of like choosing a wine bottle based on the label. Why not?

Maybe you want Green Crack or Purple Monkey Balls growing in your garden, and that’s OK. It’s also fine if you stick to something friendlier sounding, like Cherry Pie or Mango Tango.

Acapulco Gold? Pineapple Express? White Widow? All classics. Go for it. But it’s important to understand that at this moment in time, there’s no accountability or regulation when it comes to genetics and names. OG Kush sold from two different vendors might have vastly different DNA.

It’s also important to understand that seeds with the exact same DNA will still produce distinct plants with their own unique expression of cannabinoids and terpenes. Terroir–a.k.a. soil and climate–impact how a plant grows and what chemical compounds eventually pack its flowers. Environment plays a huge role in a plant’s ultimate expression.

If you can connect with a local community of outdoor cannabis growers, they’ll be your best bet for telling you what cultivars do well in your particular climate. It’s highly likely that they’ll have a few extra seeds to share too. Over time, plants grown in a specific climate and allowed to produce seeds will adapt better and better to that particular locale.

growing tips

Read More