Confusion sometimes surrounds the Cannabis industry’s ultimate product. Discover what goes into producing some of today’s favorite strains.
By Paul Lembeck
Haze, Northern Lights, Skunk #1, Blueberry, New York Sour Diesel, OG Kush, Chem Dawg…
Today, the flowers of these legendary strains and their famous descendants are found in labeled dispensary jars next to a dizzying array of other “strains.” Cannabis professionals, including budtenders, should have a basic understanding of what constitutes a Cannabis strain and what goes into breeding one before naming it—but many do not.
Let’s look at what makes a strain and compare how the classics were created with how breeding is trending in several directions today.
What is a strain exactly? In mainstream horticulture, the term cultivar (a combination of the words cultivated and variety) would be used to describe a Cannabis strain. In this context, a Cannabis strain is a lineage of plants descended from specific parents that are selected for favorable traits and that, when bred to each other, produce offspring that are very similar in appearance and other qualities. This similarity is what Cannabis breeders refer to as “stable” when describing their projects. Multi-generational stability is a crucial goal in creating strains; one-generation stability is the goal when creating a hybrid. That confusion between the two terms, and the labeling seen in some stores alluding to mixed indica/sativa phenotypes as “hybrids,” lies at of the root of the currently chaotic strain-naming situation.
Plant Breeding Basics
Let’s quickly review what plant breeding entails. Plant breeding is selectively manipulating gene frequencies in populations—increasing desired and decreasing undesired inheritable traits. This can be done on a very small scale between a few plants, or with acres of plants cross-pollinating. Hemp breeders work with very large numbers of plants, while medical Cannabis-breeding endeavors tend to work with a few plants. Hemp and resin-strain medicinal breeders create both hybrids and strains—but very differently.
To visualize how manipulating gene frequencies by breeding works, imagine two glasses of colored liquid, one blue and the other yellow. The blue liquid is one stable population—a uniformly blue “strain” analog. The yellow liquid is a different genetically stable “strain.” Mix the two together completely—the equivalent of allowing a yellow and blue population to interbreed freely—and the resulting product is colored green. The colors are analogous to two genetic makeups—or genotypes—that have combined equally, resulting in a uniform first-generation hybrid. Imagine now that when the green liquid is stirred up and left to settle, it suddenly differentiates into a large number of very differently colored yellow, blue, and green globules. The many different colors represent phenotypes and illustrate what happens on a genetic level when a hybrid is left to pollinate itself. Selecting one of those resulting phenotypes—a turquoise one, perhaps—and combining it with a similarly colored one would be the beginning of making a strain, or inbred line. Once repeated mating consistently results in the settled products being a similar shade of turquoise, it has become stable. If the turquoise color cannot be matched successfully with another, or is otherwise so immediately desirable that the grower wants to multiply it, the desired phenotype could be divided into many duplicate pieces—the equivalent of making clones. Interestingly, if the original green mixture were allowed to mix and settle repeatedly without interference or artificial selection, it would eventually shift its dominant shade until it stabilizes to suit its environment. This new overall color is analogous to what would be called a landrace—a naturalized strain adapting to its changing environment.
Achieving desired breeding results with plants of the genus Cannabis is approached by two different methods that vary by scale and focus; the basic concepts are the same. Largescale Cannabis breeding—think industrial hemp—involves the physical separation and maintenance of large open-pollinated cultivar populations, which are used for specialty crops and also to breed with other cultivars of dissimilar but complementary genetics to make vigorous hybrids. This is agricultural-scale plant breeding, just like any other wind-pollinated crop.
Cannabis breeding for the medical and recreational market is not based on normal agricultural selection constraints concerning industrial-scale farming: harvesting, storage, and processing of the final crop. The most important traits that are selected for in medical Cannabis are based on the flowers: cannabinoid content, terpene profile, cerebral and physical effects, density, and calyx-to-leaf ratio. These are the focal points of the modern marijuana breeder’s goals, not uniform seed size and oil content, pathogen resistance, even maturation, etc. Therefore, medicinal Cannabis breeding is actually a form of floriculture, and the breeding methods are modified from agricultural open-pollination to very selective pollination and intensive inbreeding practices widely used in developing specialty flower crops, such as roses. The end result of these breeding projects is often a clone, a single plant exhibiting such desirable traits that cuttings or tissue culture techniques are used to propagate it for greater yields of consistent qualities. Other breeding efforts strive to make predictably elite phenotypes available in seed form.
One of the first United States Cannabis strains developed for the recreational market of the 1970s was the legendary Haze. Haze was created in California by crossing Colombian, Mexican, Thai, and South Indian imported Cannabis strains over a period of several years by Santa Cruz-area growers (the Haze brothers) outdoors and in greenhouses to extend the season required for this long-flowering strain. Some seeds of Haze found their way to the Netherlands, where they were used in other breeding programs. Neville Schoenmakers performed the most notable breeding work with Haze during the Dutch era, and his resulting Neville’s Haze—a cross between Haze and Northern Lights backcrossed repeatedly to Haze—is widely used in breedingtoday. Most Haze crosses use Neville’s Haze as the parent. The common characteristics of Haze still exist in these lines today—the benchmark of a stable strain—while continuing to evolve in different directions, an inevitability due to the inherent nature of Cannabis to maintain genetic diversity.
Northern Lights came from a similar storied history to most of the earliest strains. The most common account is that a man living on an island near Seattle bred a pure Afghan line that produced 11 select phenotypes. These 11 types made their way to the Netherlands where Mr. Shoenmakers and other Dutch breeders worked with them. Although all of the original Northern Lights family plants were pure Afghan genotypes, Thai has made it into some of the lines. Northern Lights is one the most successful strains of all time, winning Cannabis Cups year after year during the early Dutch Coffee Shop days. Northern Lights is still being line-bred and crossed with other strains today, a tribute to its outstanding properties and general combining ability with other strains.
On the other side of the Atlantic, another breeding project took place between Afghan broad-leaf and equatorial Colombian thin-leaf genetics. In California’s Bay Area, a group of breeders worked with Afghan and imported North and South American strains. One project involved a cross between Colombian Gold and Afghani that was unstable. Though the project was scrapped, a special plant was reserved by a member of the breeding crew. This plant was the beginning of Skunk #1. Because the plants resulting from this individual were variable and difficult to finish at the latitude they were growing in, they were crossed with a more northern sativa from Mexico—the legendary Acapulco Gold—with the prototypical Skunk, and the stabilized result was Skunk #1. This project was notable because established breeding practices used in agriculture were being applied during this time.
Some strains are iconic, as are some of their creators; DJ Short certainly fits that bill. No other Cannabis breeder has been as transparent and self-documented as Mr. Short, and his writings on Cannabis breeding—and the cerebral effects he breeds for—are timeless classic reads. His writings are detailed explanations of his meticulous record-keeping method and the specific procedures used to create his best-known creations: Blueberry and Flo. Short stresses the importance of choosing parent plants from stable populations of first-generation (f1) hybrids made between stable strains as parental stock. Plant breeding is a numbers game, and Short had access to relatively large numbers of individuals from which he could take selections. To stress the importance of working with large numbers, consider this: If a breeder were tracking just six inheritable traits that have different alleles for those traits (heterozygous), 729 resulting genotypes are possible, and the breeder would need to grow a minimum of 4,096 different plants in the f2 generation to have a chance of all of them occurring.
With the steady decline in outdoor growing and a surge toward indoor growing, the ability to perform breeding work with large numbers of plants has decreased accordingly. Two strains that are very closely related, New York Sour Diesel and Chem Dawg, had been sourced from indoor grow projects. The twoare descended from a population of plants from the West Coast of the U.S. A pound of what was called “Dog Bud” by the sellers was distributed at a Grateful Dead show, and one of the buyers got 13 seeds in a bag. Those seeds eventually made what was to become New York Sour Diesel and Chem Dawg. Both have a sharply distinct taste and aroma, with a great high. One artifact of the indoor growing boom was the decline of seeds as a genetics source, and Chem Dawg “D” is only seen as clones of the original plant. Male plants are a liability in an indoor grow, used only to make more crosses, and Chem Dawg and Sour Diesel are seen as clone-only usually—though they have been treated at times to make feminized pollen, and feminized seeds are available. As female breeding plants, the clones have been used many times.
There is no better example of strain-naming confusion than OG Kush. The original version(s) were undoubtedly related, but today the Kush moniker is applied to a dizzying array of “strains,” many of which likely have no real link to the original concept of OG Kush.
Strain Names and Marketing
Cannabis strains are inbred, interbred, and backcrossed repeatedly in breeder grows. The same genetics can be reshuffled multiple times with varying results. I can safely say that almost every flower variety in a Cannabis shop shares common and recent ancestors with those inside jars on the same shelf. Yet they’re different from each other in subtle or not-so-subtle ways, and those can be classified into general and understandable families—just as styles of beer fall into different categories. All true Haze-heavy plants, whether elite clones plucked from a breeding project or meticulously maintained pure lines, should have the Haze aroma, taste, and effect. The same is true for the Chem/Diesel family. If a flower smells and tastes like Chem Dawg or Sour Diesel, then that’s the category where it belongs—not simply because it has the words “Chem,” “Dawg,” “Sour,” or “Diesel” in its name. The descriptor “Sour” shouldn’t have more weight in the explanation of the strain than its actual aroma and taste. Indicas and sativas, regardless of their different taxonomy, can be—and usually are—thoroughly intertwined in many of the flowers available today. With breeding, it’s entirely possible to get a plant that combines a sativa plant structure with an indica chemo-type. There is not as clear a distinction today as when there were many landrace indicas and sativas to compare. It might be helpful to think of different clones or true strains as a specific brewery’s stouts, lagers, and ales; they have varying ratios of hops and malt, just as Cannabis has varying chemical compositions that are distinguishable enough to classify certain strains together.
With the advent of legalized medical and recreational Cannabis in many states, new “strains” are seen every day. This can pose challenges for aspiring Cannabis professionals. What’s the best way of providing useful and accurate information to customers without overwhelming them or confusing them with lingo when new flower varieties appear in stores? Cannabis professionals, including those in the retail sector, may want to consider the perspective of their customers when making “strain” descriptions and recommendations. Instead of a rambling explanation like “This is a really new strain our grower just made called ‘McTasty’ that’s a triple backcross sativa-indica hybrid outcrossed with a local Sour OG, so it’s possibly related to Sour Diesel—sure smells and tastes like it,” they may want to opt for this easy-to-understand alternative: “This flower is a new Diesel type, with its own subtleties, as well. If you prefer the effects of Diesel crosses, this is an excellent one to consider.”
As a Cannabis professional, it’s important you understand the logistics involved in producing Cannabis strains, breeding specifics, and naming conventions—as having that knowledge will help you better meet your customers’ needs and expectations without adding confusion to the mix.
The Role of Clones in Breeding and Naming
The use of clones in mainstream horticulture is very common. Most ornamental plants sold at nurseries have labels with the common name and a more specific clonal name, for example: Rose “Peace.” Often these plants are vegetative clones more commonly known as cuttings. “Clone-only” in Cannabis breeding means there are no seeds available, only elite female phenotypes propagated by taking cuts. Clones can be induced to make male flowers by subjecting a plant to stress or applying chemical/hormonal sprays. The resulting pollen can be used to make seeds, which are predominantly female and—by their very method of genesis—instantly inbred. These can be bred to great effect by crossing with a genetically distant strain for hybrid vigor. They can also stunt growth if used with a very similar mate, a phenomenon known as inbreeding depression.
Naming is tricky. Should we be using the strain name or a clone name when describing different phenotypes and clones? One regrettable trend that is emerging in Cannabis cultivation is for a warehouse grower to grow out seeds of a strain—Super Lemon Haze, for example—and select a choice phenotype to clone. The grower decides to call his clone “Lemon Zest,” and labels the jar in the shop accordingly. This makes a confusing situation even worse. Perhaps a naming standard that reflects the parentage of the clone would help. One way that practice could look is this: Cannabis Super Lemon Haze “Lemon Zest”™ … thereby acknowledging the original genotype while protecting the grower’s own elite creation with a trademarked name.