In Seattle’s industrial SoDo neighborhood sits House of Cultivar, an award-winning indoor cannabis farm with a passion for growing and preserving premier cannabis genetics. No matter what genetics they run, either seed or clone, all start in their tissue culture lab.
With a steady rotation of new and exciting strains, House of Cultivar puts out an evolving mix of trending flavors. Each is grown with their insightful approach, close attention to detail, and acute vision of quality.
Tissue culturing is the process of propagating fresh plants by growing them from a cellular level in a controlled and sterile environment. Also known as micropropagation, tissue culturing can mitigate risks that pests and pathogens pose to cannabis. It allows plants to grow robustly and vigorously, giving each a clean slate from which to grow toward their ultimate genetic expression.
“We operate with the motto that an ounce of prevention is worth a pound of cure.”
Matthew Gaboury, Founder, House of Cultivar
There are many advantages to utilizing tissue culturing in cannabis farming. It can reduce overall cultivation costs, especially when you consider the resources needed to maintain a large and diverse library of genetics.
Starting and sterilizing genetics at a cellular level gives House of Cultivar the ability to rejuvenate old, tired genetics and to cleanse new genetics coming into the garden that may have questionable health or potential genetic defects.
They’re also able to manage hundreds, if not thousands, of genetic variations without having to dedicate the space and labor needed to keep mother plants alive and healthy.
Watch the full episode of Only the Best to dive deeper into the tissue culture process and see how House of Cultivar applies these innovative, sustainable practices to produce high-quality characteristics from their expansive genetics library.
Ever wonder why the same strain of cannabis can be slightly different, depending on which store you get it at? A gram of OG Kush from one grower who sells to a particular dispensary will be slightly different from another grower’s OG Kush at the dispensary across town. Although they are the same strain, these are different phenotypes (or “phenos”)–different expressions of the same genetic material.
If two cats–one an orange tabby and the other a black and white calico–have a litter of kittens, some of the kittens will be orange tabbies and some black and white calicos. Some may even be black and white tabbies. So too, do different cannabis phenotypes have different traits from one or both of their parent strains.
When a grower decides to produce a particular strain, they typically get a packet of seeds from a breeder, each one a different phenotype of that strain. After growing each seed, the grower will pick the best one because of its characteristics, picking for yield, bud density, smell, flavor, potency, color, and many more attributes, and discard the others.
This narrowing process usually takes a few generations of selection, and months, sometimes years, but in the end, the best pick will be mass produced for sale, and that’s the cannabis you buy off the shelf at the dispensary.
The Importance of Labeling
Selecting phenos is a meticulous process. Organization and keeping track of things through the long growing process is imperative. You’ll be taking clones of each phenotype and keeping some while discarding others, so it’s important to label clones according to their originals phenos and to not mix up any.
To start, plant all of your seeds and label each one with a separate tag. So if you’re growing 10 phenos of OG Kush, you would assign them “OGK 1,” “OGK 2,” etc., up to “OGK 10.” The order of the numbering doesn’t matter, but make sure that a number always stays with the pheno you assign it to.
Grow out each seed until they are 6-12″ tall, or big enough to clone. This will probably take about 3-6 weeks.
Take a clone of each phenotype and number each clone to its corresponding original: the clone of “OGK 1” would also be named “OGK 1” and so on.
If you’re starting out with ten seeds, you should now have 20 plants: 10 seedlings and 10 clones.
Clone, Flower, Discard
After you have taken clones, grow them separately in a vegetative state. When the original phenos are big enough, after at least 2 months in the vegetative state, put them on a flowering light cycle (12 hours of dark, 12 of light).
After about 8-10 weeks of flowering, these original phenos will be ready to harvest for buds. Some phenotypes might finish sooner than others and each will probably be slightly different. Now you will discard some of the phenos based on their poor quality and keep the ones that have good qualities.
A lot of seeds come pre-feminized, but if you are starting out with male and female seeds, you will need to determine the sex of the plants first and discard all of the males, because only females produce buds. Reproductive organs appear a couple weeks into the flowering cycle, and if you have any males, discard them and their corresponding clones and keep flowering the females.
When harvesting each phenotype, take meticulous notes of each pheno’s bud structure, yield, smell, density, and overall appearance. Some phenos can be discarded right away, as it will be easy to tell that they won’t produce quality buds. Whenever you discard a pheno, discard its corresponding clone that’s in the vegetative state.
You can still use the harvested buds from discarded phenos. This product may not be as desirable because it’s from the phenos that didn’t make the cut, but a lot of growers will sell this for pre-rolls or extracts, just usually not quality flower.
Repeat the Process
The process is repeated. If you started with 10 phenos and discarded six after the first round of flowering, you’ll be left with four. Take a set of clones off of these four–a second generation of clones, or clones from clones. Keep this new second generation in the vegetative phase separately, and flip the first generation of clones into flower.
This first generation should be big enough to flip into flower now because they were growing vegetatively while the original phenos were flowering. But you can always grow these out more vegetatively if you want bigger plants.
After flowering these four remaining phenos, harvest them and take more notes. Discard the ones with poor qualities and their corresponding clones and keep the ones with good qualities.
Continue this process until you’re down to one pheno. That is your winner!
You don’t want to discard a pheno with possible good qualities, but keep in mind that the less you discard, the more rounds of cloning, flowering, and discarding you’ll have to do.
Often, commercial growers will go through at least three rounds of generations of this selection process to get the final pheno, sometimes even more.
You can see how this is a time-consuming process. Three generations of flowering phenotypes, if each round takes about 8-10 weeks, is 24-30 weeks alone. Add on top of that another month or so for the seeds to germinate and get to an initial size in which to clone off of at the beginning of the process, plus time to harvest, dry, and cure buds at the end.
So before that OG Kush from your favorite grower hits the shelves for the first time, they have been growing and narrowing it down for 7-9 months at least, to get you the best version of that OG Kush. That phenotype is now their “cut” of that strain.
Cannabis–like asparagus, dates, mulberry, ginkgo, persimmons, and spinach–is a dioecious species, meaning that the male and female reproductive structures involved in propagation are typically found on different individual plants, rather than on a single plant (as in a monoecious species). Cannabis is also an annual, so it dies off each winter, but not before dropping seeds that will sprout the following spring, allowing the cycle of life to continue for another year.
Only the most successful cannabis hybrids will be stabilized and grow popular enough to earn a permanent place in the hearts of cannabis enthusiasts.
In nature, those seeds form in the late autumn–when the male plants pollinate the females. Each time such pollination takes place the result is a genetically unique seed–one that contains DNA from both of its parents–but without the direct involvement of human beings, the amount of genetic diversity seen from generation to generation is practically pretty limited.
In theory, each time two unique varieties are crossed in this way, the result is a wholly new strain. But in practice, only the most successful of these hybrids will be stabilized and grow popular enough to earn a permanent place in the hearts of cannabis enthusiasts. Adding to the complexity (and potential confusion) of this process is the fact that until relatively recently, all of this breeding still took place in the underground, so the documentation of who created what and how is often unknown or in dispute.
But that’s just all the more reason to properly identify and honor the amazing cannabis breeders of yore who performed the alchemical feat of bringing into the world all-new, genetically distinct cannabis varietals that truly changed the game.
Dave Watson (a.k.a. “Sam the Skunkman”)
One of the most fascinating and controversial figures in cannabis history, Dave Watson (far better known as “Sam the Skunkman”) is lauded by some and vilified by others, but nobody can dispute the outsized role he’s played in the once very small world of cannabis breeders.
Watson’s journey began in Santa Cruz, California in the 1970s, where he was linked to two of the earliest cannabis breeding outfits to ever gain notoriety–the Haze Brothers and Sacred Seed Collective–both of which were instrumental in developing the early hybrid strains that helped transform American “homegrown” cannabis from a ditchweed laughingstock to the envy of the world.
In 1985, Watson was reportedly arrested on cannabis charges in California. A month later, he landed at Amsterdam’s Schiphol Airport, allegedly with a box of 250,000 seeds that included Skunk #1, Original Haze, and Afghani #1–all of which had been bred or stabilized by his cannabis compatriots. Watson met immediately with emissaries from Amsterdam’s burgeoning cannabis scene, which at the time relied largely on imported hashish to supply its coffeeshops.
Along with Robert Colonel Clarke (Author of Hashish! and Marijuana Botany), he would go on to form Hortapharm, a company dedicated to collecting cannabis seeds from around the world, both to create a stable genetic library and to breed new hybrids with desirable traits. By the late 1990s, they were doing business with Dr. Geoffrey Guy, founder and chairman of GW Pharmaceuticals, which is now licensed by the British government to cultivate cannabis for use in making “whole-plant extracts” with specific ratios of THC and CBD for use as prescription medicines.
GW has since created “the first cannabis plant-derived medicine ever approved by the FDA,” but at the time, the company was in its earliest stages and still looking for cannabis seed stock to use in developing its pharmaceutical preparations.
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In the late 1960s, Netherlands native Ben Dronkers sailed on merchant ships to exotic ports of call, where he initially sought out fabric to start his own clothing company, but eventually began collecting local cannabis seeds instead. In time, his collection was truly unparalleled and boasted genetics from throughout Central Asia, Southeast Asia, and the Indian subcontinent. He then used those landrace strains to breed his own hybrids.
In 1985, Dronkers formed Sensi Seed Bank and began offering for sale the strains he’d collected and hybrids he’d created, including after crossing his own discoveries with recently arrived American varietals.
Among his most endearing and enduring contributions: Jack Herer, one of the all time most popular cannabis strains, named for one of the all-time most influential cannabis activists.
According to a lengthy 2013 Grantland profile titled “The Willie Wonka of Pot,” DJ Short–the legendary, nearly mythical cannabis breeder behind Blueberry and many other classic strains–is part of a long line of plant medicine workers. His great-grandmother “used to grow pot, opium, tobacco, sage, and lavender in a backyard garden. The curtains in his grandmother’s house were made of hemp. His family used to joke, ‘If the house catches on fire, stay in for a little while and breathe.'”
In 1973, he bought a box of cereal that came with a seed sprouter as the prize inside. That inspired him to try growing the seeds he’d collected.
Colombian Gold (“The smell was that of sandalwood incense, almost frankincense, and the flavor was that of a peppery incense cedar … truly psychedelic, powerful and long lasting”), Chocolate Thai (“deep, rich, chocolate, nutty, woody/spicy”); Jamaican (“Too damned strong and speedy! … It is a heart-lifting herb and I have a sensitive heart. So I am careful with the samples of the commercial J-ganga that I try”).
Then one day, in 1973, after moving to Oregon, he bought a box of cereal that came with a seed sprouter as the prize inside. That inspired him to try growing the sativa seeds he’d collected as a youth, but he found they took too long to mature and yielded too little. Next he tried smoking some indica, but found it didn’t stoke his inspiration or spark his imagination the same way as sativa.
So he set up a 16-square-foot closet grow and began to breed his own strains, mixing sativa and indica varietals and scrupulously smoking the results until he produced not just Blueberry, a marquee strain with the hue and aroma of fresh berries, but also Flo, Blue Velvet, Azure Haze, Whitaker Blues, Vanilluna, and many other varieties that have collectively changed the game–as has DJ Short’s tireless research into cultivation and breeding practices, a lifelong pursuit he continues today.
Don and Aaron (the D and A of DNA Genetics) met in Southern California and initially enjoyed the symbiotic relationship of weed dealer and customer. Then they became friends. And finally business partners.
There was never any question that they’d enter the cannabis business, as both men share a true and abiding passion for the plant. But rather than try to compete in the still grey market medical cannabis industry developing in the United States at the time, in 2004 they decided to pull up stakes and open up shop in The Netherlands.
The move put them in direct contact with Amsterdam’s legendary cannabis scene, which had been serving as a center of breeding and seed banks since the days of Dave Watson and Ben Dronkers back in the 1980s.
As new kids on the block, Don and Aaron brought with them not just enthusiasm and youthful energy, but also a whole new generation of prized California genetics which they used to create next-level cannabis hybrids like LA Confidential, Chocolope, Tangie, and Kosher Kush.
More recently, they’ve moved their operations back to California, where they’re firmly established among the largest and most respected cannabis brands in the game today.
Before humans began actively breeding cannabis strains for desired traits, the plant produced much less THC than it does now, and lots more CBD–perhaps even a 1:1 ratio of its two best known and most plentiful cannabinoids. But because CBD isn’t intoxicating like THC, underground breeders seeking higher highs for decades unwittingly bred CBD out of the cannabis gene pool.
Sour Tsunami, bred by Lawrence Ringo, was the first stabilized CBD-rich strain found in California–a discovery that led to a revolution in medical cannabis.
Well aware of CBD’s therapeutic potential, however, in 2010 a non-profit organization called Project CBD formed to boost research into the compound, and help identify and proliferate what few CBD-rich cannabis varietals remained in circulation. From its inception, Project CBD partnered with California’s commercial cannabis testing labs to flag any bud testing high in CBD, in order to build up a breeding stock of high-CBD strains.
Sour Tsunami–bred by Lawrence Ringo of Southern Humboldt Seed Collective–was the first stabilized CBD-rich strain they found in California, a discovery that led to a revolution in medical cannabis.
Ringo himself had begun growing as early as 1971, though he remained largely in the underground until 2010 when he founded his seed company. That’s also when he had his crops lab tested for the first time, and discovered the unique medicinal properties of Sour Tsunami were due to its high CBD content (around 11%). From then until the end of his life in 2014, he focused on developing additional CBD-rich strains, including Harle-Tsu, Canna-Tsu, Swiss-Tsu, and ACDC.
While browsing Leafly’s strain database, you may wonder what a cross of this and that strain is, what a hybrid or a backcross is, or what a parent strain is. All of these have to do with plant breeding–essentially, breeding a male and female plant to combine or refine the genetics of two plants or strains. Breeding two different strains often results in a new strain, or hybrid.
Cannabis breeders typically breed to purify and strengthen strains, combine strain traits, or enhance specific characteristics.
Cannabis breeders typically breed to purify and strengthen strains, combine strain traits, or enhance specific characteristics like higher yields, specific aromas, potency, and many other things.
When growing and breeding, it’s important to know where your seeds come from and what kind of genetics they have. If the seed breeder can’t give you a detailed history of how a packet of seeds was bred or what they were crossed with, you never really know what you’re getting.
Plant breeding is a fundamental process of growing cannabis. Breeding is highly technical and typically done on a commercial scale, but with legalization increasing, breeding is becoming more popular. You can do even do it yourself.
The Basics of Breeding
Cannabis plants can be either male or female. Cannabis consumers are mainly concerned with female plants, because only females produce the sticky buds that we all know and love. But male cannabis plants are important for the breeding process, as they are needed to pollinate the bud-producing females.
Take the strain Super Lemon Haze as an example. It’s a hybrid (or a “cross”) of Super Silver Haze and Lemon Skunk–these are the parent strains. At some point, the breeder decided that they liked some attributes of Super Silver Haze and some of Lemon Skunk and decided to combine the two.
To do this, you need a male of one strain to pollinate a female of the other. Once pollinated, the female will then produce seeds that express the genes of both the male and female plant. Those seeds will be harvested and grown separately, and voila: You have created a hybrid.
So how do you know whether to pick a male or a female of each strain that you’re crossing?
“Often in cannabis, the traits of the female carry over to progeny (seeds) more than the male. That said, the traits of the male are often obvious to the discerning grower so one should definitely choose a male that will complement the traits of the female,” says Nat Pennington, founder and CEO of Humboldt Seed Company who’s been breeding cannabis for 20 years. “So much is possible with truly intentional breeding strategies.”
How to Breed Cannabis Plants
After two parent strains are selected for breeding, a male and several females are put into a breeding chamber to contain the pollen. A breeding chamber can be as simple as an enclosed environment with plastic sheeting on the sides, or a specially designed sterile environment for large-scale breeding.
“A healthy male can pollinate up to 20 females, and by pollinate, I mean absolutely cover the plant with seeds.”
Nat Penningon, Humboldt Seed Company
A single male plant can pollinate tens of females. “It’s always a good idea to have only one male, genetically speaking, per pollination effort,” says Pennington. “A healthy male can pollinate up to 20 females, and by pollinate, I mean absolutely cover the plant with seeds.”
This is intentional breeding–any grower who’s accidentally grown a male and pollinated a crop will know that one male can easy pollinate hundreds of females, filling your whole crop with seeds.
Once in the breeding chamber, you can grow the plants vegetatively for a few weeks to let them get bigger, but it’s not necessary. Put them on a flowering light cycle: 12 hours of light, 12 hours of dark.
The mature male will grow pollen sacs within the first couple weeks of its flowering phase. Pollen will release from the sacs, move through the air, and land on the female plants, pollinating them. Having an enclosed breeding chamber is important to contain the pollen and also to prevent outside pollen from getting in.
You can also help along the pollination effort by shaking pollen from the male onto the females, or by collecting pollen from the male and directly applying it to the females. These female plants will continue to grow and flower, during which they’ll grow seeds (as well as buds). These seeds will express the genetics of both the male and female plant.
When the seeds are mature, they are harvested and stratified (or dried). “The secondary process of maturation happens after the plant is dead, and the seed needs to be stratified before it will germinate,” says Pennington. “In general, harvest for flower takes place three to four weeks before harvest for seed.”
These seeds–now a hybrid of the two parent strains–will be grown on their own, outside of the breeding environment.
But the process doesn’t end there. The hybrid strain that you buy at the dispensary has likely gone through many rounds–or generations–of breeding to strengthen its genes and to ensure that its descendants are healthy and consistent.
Just as you and your sibling might have different physical attributes from your parents, each seed created from a round of cross-pollination will have different attributes from its parent strains. Maybe you have your father’s eyes and your mother’s hair, but your sister has your mother’s eyes and hair. Each cannabis seed is unique and will express different traits, and different combinations of traits, from one or both of the parent strains. These seeds with various expressions are called phenotypes.
Homozygosity ensures that a plant will consistently produce the same seeds with the same genetic makeup over and over again.
A plant that produces a set of phenotypes that have a lot of variety are said to be heterozygous. With cannabis, you typically want seeds that are homozygous–ones that have the same set of genes. Homozygosity ensures that a plant will consistently produce the same seeds with the same genetic makeup over and over again, ensuring that buyers and consumers will get the same plant or seed time and again.
After a strain is crossed, a breeder will then have to select which phenotype of the new strain they like best. For large-scale growers, they want to choose the best phenotype for mass production.
Back to the Super Lemon Haze example: This strain takes a lot of its bud structure, trichome and resin production, and overall appearance from Super Silver Haze. But it takes its flavors and aromas from Lemon Skunk.
Lemon Skunk also tends to grow extremely tall and has loose buds, whereas Super Silver Haze grows smaller and has denser buds. Through selecting specific phenotypes, a breeder can pick one that has the attributes they want to keep. In this case, a phenotype that has the structure and bud density of Super Silver Haze and the flavors and aromas of Lemon Skunk.
Most likely, there were early phenotypes of Super Lemon Haze that grew tall and loose like Lemon Skunk, or tasted more like Super Silver Haze. But the breeder discarded those phenotypes and keep growing the ones that have the attributes of what we now know is Super Lemon Haze.
High-quality breeding still doesn’t stop there. Once a breeder has crossed a strain and narrowed down a phenotype and finally has the one, they will usually backcross that strain to strengthen its genetics.
Backcrossing is a practice where a breeder will cross-pollinate the new strain with itself or a parent–essentially, inbreeding the strain. This makes the strain more homozygous, and strengthens its genetics and desirable characteristics, and also ensures that those genes continue to pass down from generation to generation.
The hybrid that you bought from the dispensary has gone through months and even years of growing, crossing, and backcrossing, as well as a selection process to pick the best phenotype of that strain.
Breeding is about time and patience. Says Pennington: “To be a breeder, you have to be willing to accept the fact that you won’t have uniformity in the offspring, [you’ll get] lots of ugly ducklings in the hunt for your golden goose. To make seeds that will actually reflect the golden goose takes time, and it takes more than just a one-off cross. Even after you found your golden goose, expect to have to do a whole number of stabilizing backcrosses to reproduce your golden goose in seed form.”
You just picked up a new strain that you’ve been waiting to try. The moment you get home, you rip into the package and take in its smell. When you dive in deeper, you spot something buried within the bud. It’s small, round, and has an outer casing.
Congratulations, you’ve found a seed. More specifically a bagseed, as the seeds found in packaged or bagged flower are commonly called.
Maybe congratulations aren’t quite in order. Depending on where it came from, who you ask, and if the seed is viable or not will affect your level of excitement.
While finding a seed in your stash is not ideal for truly exceptional flower and much less common than it once was, it is a pretty ordinary occurrence. Anyone who has been smoking cannabis for some time has undoubtedly come across a bagseed. Sometimes you’ll notice one when grinding down some flower or you’ll see it pop, spark, and crackle as the heat of your lit bowl pops the precious kernel within.
Ok, so you found a bagseed. Now what?
Is Bagseed Good or Bad?
Seeds found in finished cannabis flower can develop for a number of reasons. A nearby male plant can accidentally pollinate a flowering female. More commonly, though, they’re a sign of stress and can be attributed to high temperatures during the final stages of flowering or an exaggerated spike in climate or environment.
Seeds can also form in plants with genetic disorders or instability, like hermaphrodites–plants that develop both male and female reproductive parts. Generally these conditions are viewed as negatives, and for that reason alone, temper your expectations with any plants you start from a bagseed.
If found before lighting it on fire, the first thought from excited smokers is: “Let’s grow some weed!” But before you jump in headfirst, ask yourself a few questions to help decide if it’s worth the time and energy to grow the seed.
Was the Seed Found in Good Cannabis?
The first and most apparent question you should ask yourself is whether you enjoy the cannabis that the seed turned up in. If you don’t like the flavor, effects, or even the looks of the bud, then it’s probably not worth growing.
Strains like the legendary Chemdog wouldn’t be possible without adventurous smokers planting and proliferating the seeds they found in a bag.
Sometimes you’ll get lucky and find a mature seed in some really nice herb. Strains like the legendary Chemdog wouldn’t be possible without adventurous smokers planting and proliferating the seeds they found in a bag of kind bud.
So don’t discount your bud just because there’s a seed or two in it. While not ideal, it could be the origins of the next great cannabis strain.
Are You Ready to Grow?
Growing cannabis takes a certain level of commitment. Plants need nurturing for months in the right environment with a close eye for detail. All this takes investment. Whether it’s time, energy, or financial resources, you’ll have to commit to the whole process if you want to produce something you’re proud of.
Fear not! If you’re simply curious to learn how cannabis grows and less concerned with the overall outcome, you can plant a couple of bagseeds outside and see what the result are.
If you’re ready for a more serious approach, make sure you have the space for a proper garden and pop the seeds to see what fruit they bear. That is, if the seeds you found are viable.
Is the Seed Viable?
If you like the strain and you’re ready to grow, then it comes down to whether or not the seed is viable, or able to successfully germinate. For a seed to be viable, it must be mature enough to have a completely formed genetic blueprint and it must be strong enough to “pop” through its hard casing and sprout its crucial tap root.
Immature seeds tend to be light in color and have a soft outer shell.
Stress on a plant and unstable environments can produce bagseeds, and often, a bagseed’s viability is questionable at best.
There are a few indicators that will give you a sense of whether the seed is worth germinating. Immature seeds tend to be light in color and have a soft outer shell.
Visual signs like tiger stripes–dark stripes that resemble tiny roots or veins on a leaf–are generally good. A seed with a solid shell will withstand a little pressure when pinched between your fingers. If it crumbles or cracks, the seed will be effectively destroyed, but don’t agonize over your loss.
In some cases, even if a seed isn’t completely mature, there’s still a chance it could be viable. But often these are extremely weak, take long to develop, and express other unfavorable characteristics. Growers usually discard weak plants to free up space in their limited gardens.
However, I’ve watched seeds that I had zero faith in their ability to germinate turn into strong, healthy plants–but that isn’t common.
You might also find a mature seed that has been physically damaged through poor handling, like rough trimming. In those cases, it probably isn’t worth the effort to try and germinate the seed.
But if the seeds you found look decent or even questionable, you might as well germinate them and see what sprouts.
Time to Germinate
Viable or not, there’s only one sure way to find out. Once you’ve decided you’re going to see what those beans can do, it’s time to germinate. Germination is the incubation period that encourages seeds to sprout and develop into a new plant.
There are a number of different ways you can germinate cannabis seeds, but they all require the same things to be successful: water, heat, and air. For a complete, step-by-step guide, check out our article How to Germinate Cannabis Seeds.
Even if your seed sprouts fast and grows vigorously, it has roughly a 50/50 chance of being female and producing seedless, cannabinoid-rich flowers.
Remember, once a seed germinates, the real work begins. Sexing, selecting, vegetative growth, flowering, and the eventual harvest all lie ahead.