Pheno Hunting: A Search for the Perfect Plant

Nobody likes to be picked last, except for weed plants. Phenotype hunting, commonly known as pheno hunting, is the process of selecting the ideal cannabis traits found within a crop of many. 

Breeders who pick a plant last during a pheno hunt decide that it has all of the desirable characteristics they’re looking for in a particular strain. 

Cannabis consumers and medical patients have so many options at their fingertips that it’s difficult to remember the data-driven selection process that goes into many of the best strains. In this piece, we talked to an experienced pheno hunter for a major cannabis breeder and dove into the ins and outs of the pheno hunting process that you may or may not know even exists.

Why Do Cannabis Breeders Bother To Pheno Hunt?

Phenotypes are genetic varieties of cannabis strains that can exhibit varying traits and characteristics—this is a significant reason why there are numerous different types of Runtz, Gelatos, and dessert strains on the market today. The difference between a properly pheno hunted strain and one that isn’t may not always be clear to the average cannabis consumer, but to experienced breeders, growers, and savvy consumers, it couldn’t be more obvious. 

Some cannabis breeders grow their flower and products to sell in recreational, medical, and black markets; however, the main goal of a commercial breeder is often to produce a viable seed or clone stock to sell to other growers and cannabis companies. Pheno hunting thoroughly provides a breeder’s idea of the closest possible representation of a particular strain.  

Cannabis Breeders Maximize Quality With Pheno Hunts

The aim of any cannabis breeder worth his or her salt is to breed and grow weed with the highest quality possible. Pheno hunting for the best phenotypical traits possible creates a scenario where individual plants can be selected for their expression of those desirable traits; characteristics that include:

• Aroma
• Terpene profile
• Appearance & bag appeal
• Bud structure
• Resin production & potency
• Disease & pest resistance
• Stress testing
• Successful feminization
• Smokeability once harvested, dried, and cured
• Pollen production

Breeders must also evaluate several different climate-related criteria relating to those traits as well.

• Outdoor flower development and quality
• Outdoor vegetative development
• Outdoor aroma, appearance, resin production, and bud structure
• Indoor flower development and quality
• Indoor vegetative development
• Indoor aroma, appearance, resin production, and bud structure

Cannabis Breeders Pheno Hunt to Stabilize Strains

Pheno hunting allows for only the most desirable traits to be passed on as a representation of a specific cultivar. Breeders select the most stable and vigorous phenotypes, then transition them into seeds, clones, and large-scale cultivation. They also keep a mother plant separate from all others to take cuttings for clones and preserve a specific phenotype of a strain. 

Stabilization provides consumers with the strain they know they’re supposed to be getting—the terpenes, look, and loudness are all there, how they should be. It also preserves the strain for future generations to breed. The viability of stabilization also includes the development of phenotypes that can resist pests, mold, stress, and disease—all very important factors for growers across all different climates and regions. 

Pheno Hunting Optimizes Yield and Growth Efficiency

Flower potency and quality matter, but many cannabis breeders also pheno hunt to create viable seed stock that other growers can cultivate. Important criteria like growth vigor and harvest yield potential get evaluated during the pheno hunt process to determine if a strain can produce a large enough yield of high-quality bud that a grower would be interested in taking the time to cultivate. 

Pheno Hunting Properly Develops New Strains

Cannabis breeders, both professional and amateur, create new strains and crosses every day. The difference is that a professional breeder then pheno hunts the most desirable plants containing the new cross across several different filial generations to stabilize it. Amateurs usually just add another underwhelming strain into the general cannabis genetic pool. 

How Do Cannabis Breeders Conduct Pheno Hunts?

Some breeders put in the hard work that pheno hunting demands across several different seasons. Others take the easy way out when breeding strains and are happy with the immediate results. This is another factor that separates basic cannabis breeders from next-level and professional cannabis breeders. 

Twenty20 Mendocino is a well-known cannabis breeder of high-quality photoperiod and autoflower seeds and strains based out of the Emerald Triangle in Northern California. The company is also famous for its massive pheno hunts that they’ve documented on social media over the years, such as the great Arcata Trainwreck pheno hunt of 2022, as well as Project Skunk, which took several years from start to finish.  

Aaron McMichael from Twenty20 Mendocino is a proverbial Swiss-Army man who helps lead the charge of pheno hunting for the company, along with a host of other responsibilities, since 2020. According to McMichael, he and his partners conducted over 26 pheno hunts in 2024. 

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It’s safe to say McMichael knows a thing or two about pheno hunting, so that’s why we picked his brain in a recent video chat to get a better idea of the process from an industry player’s point of view. 

Getting Started With A Lot of Plants, Seeds, and Clones

Pheno hunters need seed stock to initiate the very important growing portion of the hunt. Breeders have already crossed the two parent strains to form a cross they wish to phenohunt at this point—the result is thousands of seeds from the male plant part of the equation. This many seeds can offer a range of characteristics and phenotypes for the breeder to evaluate. 

Breeders plant seeds outdoors once they reach the seedling stage, on very large farms that can accommodate thousands of plants in giant fields. Pheno hunters label, tag, and sometimes track plants with a barcode. They also place plants in designated rows and sections, then track them with data collection and spreadsheets.

The Outdoor Evaluation

Plants grown outdoors during a pheno hunt can sometimes number in the thousands. Pheno hunters like McMichael try not to overcomplicate the process by attempting to evaluate them all as one giant pool of candidates. A more efficient row-by-row evaluation determines the best plant out of around 300 or so in each row first. 

“When we’re hunting in the field, we’re looking for quality. There’s a lot of quality data that goes into it, and a lot of that quality is physical, like appearance and bud structure.”, said McMichael during our chat. 

He also added, “You’re smelling plants [while pheno hunting]–-if I’m hunting a field of Trainwreck, it’s critical that the plants we’re taking cuts of, when they’re in flower, they smell like Trainwreck. If not, they immediately get pulled and culled.”

Pheno hunters also evaluate resin production as a vital trait—sometimes a plant produces such quality resin above all other traits, and winds up being perfect for making concentrates. 

Pheno hunters take clone cuttings for preservation once they select the best of each row. They eventually narrow the group down to 25–50 candidates during the outdoor evaluation. All of the growth characteristics—like structure and vigor—of their final picks are scrutinized during the growing season. Weather, pests, and other elements dramatically reduce plant numbers throughout the growing season, adding an important factor of “survival of the fittest” into the equation as well. 

READ: Growing Cannabis Plants from Seed vs. Growing Them From Clones

Outdoor Climate Stress Evaluations

Twenty20 and McMichael grow outdoors in Northern California’s Emerald Triangle region—an area known for being one of the best climates in the world to grow weed. Home growers who will eventually buy the cannabis seeds exist in different regions all over the country and the world. McMichael and team use stress farms in different climates and regions of the country to evaluate how the same plants grow and deal with stress there as well. 

“Almost all of our seeds have been grown in crazy, stressful environments, and then back in the Emerald Triangle,” said McMichael.  

The Outdoor Smoke Test

Cannabis is grown to be consumed, right? That’s why once the final 25 or so candidates for a pheno hunt get selected, harvested, dried, and cured, it’s time to conduct the outdoor smoke test. Smoke test evaluations take into consideration which phenotypes have the most similar traits, as well as the most outstanding traits—only 3-5 plants move on to the next stage. 

“When we find a winner, we try to find another joint that smokes similarly to the winner, and that way we know we’ve selected traits on a survival basis from similarities like bud structure, all the way to the smoking phase. We compare them by smoking—that ultimately reigns supreme, the smoke test.”, remarked the pheno hunting/smoke testing expert.

Indoor Phenotype Evaluations

As important as the outdoor smoke test is, it’s still nowhere near the final determinant for the best phenotype. The final phase of the pheno hunting process consists of indoor cultivation and evaluations. 

“It starts outdoors and it makes its way indoors—then we see how those strings can play together,” said McMichael. 

The same few select plants and cuts that made the grade for the outdoor evaluation are also grown indoors and subject to the same scrutiny. Aspects like indoor flower quality, bud structure, aroma, stress testing, and resin production are all judged again. Breeders also test them to see how well they react to feminization, since so many home growers prefer the convenience of not having to sex their plants. 

Another smoke test—this time of the harvested indoor plants—evaluates the character, potency, flavor, and terpenes of a particular phenotype. The breeders finally select the ideal, winning phenotype for that strain once all of the discussion and arguing have ceased. 

Pheno Hunting for the Home Breeder

You don’t have to be a world-renowned breeder to conduct a pheno hunt to get the best cannabis plants, seeds, or clones. McMichael urges home breeders to do their own pheno hunts with even 10 plants or fewer, provided they have the space to do it. He also urges potential DIY pheno hunters to take cuttings of every single plant they are growing to preserve their special phenotypes. 

“If you can clone everything, if you can bring it to flower, that’s gonna be the best way to get your selection because that would mean you have access to your veg data, your flower data, and your smoke data. That’s gonna give the home breeder the best chance of making it!”