If you’ve ever been interested in cannabis breeding you’ve probably heard the term “pheno-hunt” thrown around. At its most basic, a pheno-hunt is the process of selecting the best individual plant or plants out of a pack of seeds. In a pheno-hunt, you basically take a batch of seeds from the same parents, grow them all out, eliminate any males and flower the females. As the female plants grow and produce buds, you take note of the qualities of each plant, then select one or more individuals that produce the best cannabis. You then take those plants and create mothers to produce clones. 

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Pheno-hunting Explained

To put it in another way, in a pheno-hunt you are rejecting and eliminating all the plants grown from a cross that do not match up to your specific goal. All the female plants in a pheno-hunt are ultimately in a competition against one another. 

hand holding two green cannabis cola tops Seeking out the best phenotype is also called a "keeper". Photo credit: Shutterstock
If your goal is to produce a loud and gassy strain, you would grow a bunch of seeds, and eliminate all the plants that didn’t have a gassy aroma. Once you’ve identified the ones that do produce that pungent, fuelly scent, you would carefully compare them to find the one that is the strongest. This would be your choice or the “keeper” phenotype.  

Phenotype Definition

What the hell is a phenotype anyway? It's a term for the individual characteristics that are expressed from an organism's DNA. In the cannabis industry it's simply what a plant looks, smells, tastes, and grows like – the qualities of the plant that make it different from others.  When breeders talk about phenotypes or “pheno” for short, they usually mean a group within a population that exhibits a certain trait. In the cannabis industry it's common to see different phenotypes of the same strain, an example is the “purple pheno” of Bubba Kush which is different from the “green pheno”.

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Pheno-type Genetic Example

Think about a litter of puppies. Let's say a yellow lab and a black lab mate and have puppies. Some of the puppies are black (the black phenotype), some are yellow (the yellow pheno), and some are a mix of the two, the brown pheno.

small black plastic pots filled with soil and green plastic posts stuck in the soil. Phenotypes are essentially all sisters of each other with individual characteristics. Photo credit: Author
In the cannabis space, a phenotype can also be just an individual plant, usually demarcated by a number. An example of this is all the Gorilla Glue phenotypes out there like Gorilla Glue #4 and Gorilla Glue #5. They all have the same parents, essentially they are sisters, all similar in ways but with their own individual characteristics that set them apart. More on what the numbers mean and why they are used later, first let's start pheno-hunting.

In Search of a Keeper

The best way to have a successful pheno-hunt is to have a specific goal in mind before you even get started. This will give you a direction to follow in terms of planning.  A common example of a pheno-hunting goal is to find the most flavorful and potent individual from a batch of seeds. If this is your goal, you know you’ll need to grow out as many seeds as you have room for, find all the females from the batch, give them a label each female with a phenotype number ( #1, #2, #3…) to determine one from the other, and then flower them. 

bright green cannabis plants growing out of soil with red plant tags with numbers It is very important to label each pheno with its number and strain labeled. Photo credit: Author
You need to assess if you have enough room to keep clones (aka cuttings) of all these plants or if you are going to risk trying to revegetate your keeper phenotype. Since your goal is to find the tastiest, most potent plant, you won’t know which one is your keeper until you flower, harvest, then properly cure and test each phenotype. You’ll need room to keep all these cuttings or re-vegged plants in a vegetative state until the keeper can be determined.  If it sounds like this is going to take lots of space and time to do, you are damn right. The second thing to consider after your goal is how much space and time you have to dedicate to this project. True pheno-hunting isn’t for get-rich-quick types. You need a lot of patience, attention to detail, solid work ethic and organization. It's important to note, the more space and time you have, the better the overall results will be. Pheno-hunting is a numbers and probability game. The best female picked out of 1000 other females is going to be way better than one picked out from a batch of 10. If you have the space to go big for a pheno-hunt and grow 1000 female plants in say a warehouse, your results will be exponentially better than someone growing 10 plants in their basement. 
Man with journal in front of laptop. It is important to document the characteristics of your different phenotypes. Photo credit: Shutterstock
Whether you grow 10 plants or a 1000, good labeling and organization is going to be one of the most important factors determining your pheno-hunting success. Countless heady strains have been lost or accidentally replaced due to bad labeling. Most growers adopt the #1, #2, #3… plant labeling system where each individual plant gets its own number to track it through the growing process.  This is important for keeping track of what is what when it comes time to make selections. It's highly recommended to keep a journal during your pheno-hunt so you can document the progression of each phenotype as they flower. Taking good notes on how fast flowers appear and mature, nutrient and water uptake as well as pest resistance are all important when making later selections. 

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Let’s Make a Strain: Chicken Runtz

To show how the most basic pheno-hunt would work, let's create a hypothetical strain. It's a cross of Hippie Chicken x Runtz, or Chicken Runtz as we’ll call it. Let’s say we are gifted a batch of 100 feminized seeds of this Chicken Runtz and we want to find one female out of the lot that has the highest potency, has the fruitiest terpene profile and good enough yield to be used as a production strain. This is our goal. Luckily we have the space to grow all one hundred seeds at the same time, so we get going. We make one hundred plant tags that are labeled with the strain name “Chicken Runtz'' with their individual phenotype numbers. So it goes Chicken Runtz #1, Chicken Runtz #2…etc, all the way to Chicken Runtz #100. Each plant gets one of these tags that will stay with it for the entire hunt. The more permanently affixed to the plant the tag is, the better.


As our 100 plants reach a decent size to flip into flower, we need to decide if we are going to clone all 100 of these plants, or risk trying to re-veg them. Re-vegging is when you harvest a plant, but leave enough of the plant for it to remain alive and flip it back to the vegetative light cycle. If successful, you can use this re-vegged plant as a mother. It is totally do-able, but not recommended for the novice grower. It takes some experience getting the watering and lighting right to re-veg a plant after the shock of a harvest. 


PHOTO: clones The other option of cloning before the flower cycle ensures you have backups of your phenotypes. It takes up more space but it's a safer route so that's what we do. We successfully get 100 rooted clones of each of our phenotypes and diligently label them with their corresponding phenotype number. Now we can flower our phenotypes and rest easy knowing that if we find a keeper pheno, we’ll have a clearly labeled clone of it in our veg room.

Creating the Constant Variable

As mentioned before, all the phenotypes are essentially in competition with one another to reach our goal, the strongest and most pungent of them all. It's important to reduce any variables in our garden that might make this an unfair fight. We need to make sure every plant is getting the same exact amount of light, water, nutrients and the same environmental conditions.  This eliminates the possibility that one plant may look better than the other due to getting more nutrients, light or some other variable. Once we make sure our grow setup is dialed in, it’s time to flower. We will be sure to check irrigation, light intensity and environmental conditions regularly throughout the pheno-hunt to make sure all the plants are getting even inputs. 

Flowering The Chicken Runtz Phenotypes

As we flower our phenotypes of Chicken Runtz, we need to keep some diligent notes to make the best selection. One hundred plants is a lot to keep track of. As we are focused on our goal of the most pungent and potent, we should use that to guide our note taking. To make this an easier task we need to eliminate any plants that don’t fit the bill, so we aren't taking notes on plants we are clearly not going to be selecting. 

Cannabis plants with orange and yellow leaves You can continue to eliminate plants that are not serving your end goal. Photo credit: Author
We can eliminate any plants from the hunt that are too small, not producing enough bud, or just don’t have enough of an aroma. Our goal is all about the finished flower, so we’ll have to wait until after harvest to make the real selections. In the meantime, taking good notes of each contending phenotype is a good practice.  Eliminate any phenotypes that don’t show promise in reaching your goal. You’ll have to take out the clone backups of those phenotypes as well. Pay attention to which phenotypes are attacked by bugs or pathogens, which ones show resistance to diseases and molds, and which ones have nutrient deficiencies. This info should be used to inform your final selection. 

Harvest Time

When the time finally comes to harvest, it's good to get one more good round of notes on aroma and how pungent each phenotype is. In the notes, compare the phenos against one another. Notes like “Chicken Runtz #47 has an intense berry sweet aroma and is much more pungent than Chicken Runtz #78, but not as pungent as #11” work well to help guide you to a good pheno to select. PHOTO: harvesting After a few rounds of notes like this, we are able to narrow down our list of potentially selectable phenotypes to a more manageable number. Let's say in this case we end up with 20 finished female plants out of the original one hundred that look like they have potential to meet our goal. Now we need to test each one.

THC and Terpene Testing

How you go about testing your phenotypes depends on the goal and what kind of resources you have available. In our case, let's say we have access to a lab that can potency test each phenotype. We send in a sample of each individual pheno and get data back on THC and other cannabinoid content plus the terpene profiles.  This data can clearly show which phenotype has the highest cannabinoid and terpene content. In our case it shows that that Chicken Runtz #42 has the highest THC-a content at 32% and a total terpene content of 3%, and pheno #11 comes in second highest at 29% THC-a with 5% total terpenes. Now we can narrow down our selection to these two phenotypes because they match two of the requirements of our goal.


Next, we get our final weights on each phenotype, being careful to weigh and record each plant’s yield separately. When we compare the final weights it looks like pheno #14 yielded a whopping 6.4 ounces, way more than other pheno, but since it didn’t hit the high THC mark we can cast it aside for not meeting our goal. Out of the two phenotypes with the highest THC, pheno #11 has a yield of 4.8 ounces and #42 yielded 3.6 ounces. 

Smoke Test

All this data and numbers collection is well and good, but we all know what the real test is. Now, with all the notes and data in front of us we can finally sit down and sample some of the fruits of our labor. 

Man smoking a joint with smoke coming out of his mouth Getting to smoke your last few selected plants is a perk of pheno-hunting.
The final taste test reveals that even though Chicken Runtz #42 has a higher THC percent, Chicken Runtz #11 has a more powerful effect due to its high terpene content. In the end, we select Chicken Runtz #11 as the keeper as it most closely matched up to our original goal. We go back and find the clone of #11 and establish it as a mother. All the other left over clones/phenos are eliminated from the garden to prevent any confusion.  Something should be said about “outlier” phenotypes here. One of the most exciting things about pheno-hunting is the possibility of finding something completely unexpected. Occasionally during a pheno-hunt you’ll run into a plant that exhibits a novel trait or a more expressed version of a trait, maybe a new combination of terpenes or cannabinoids. In our example, phenotype #14 had a way higher yield than the others. While it didn't meet our current goal it could be useful for a breeding project or as a high-yielding commercial cultivar. Keep an eye out for the outliers as some of the best strains are developed from the unexpected. 


Our example was kind of the quick and easy way to describe the basics of a pheno-hunt. Different growers and breeders will all have their own nuanced methods they add, but the basic principals are the same.  You don’t need to have access to a lab to get potency analysis, the tried and true method of the taste test can tell the experienced cannabis consumer everything they need to know. It does help to have as much information, feedback and data as possible when making the final decision though, so be sure to always keep good notes.  The hunt is on fellow growers and cannabis breeders. Sow your seeds and select your best. 

Frequently Asked Questions

What Should I be Looking for When Pheno-hunting?

You are looking for the best, most expressed version of the traits that make the qualities of a strain with a specific goal in mind. For example, If you are pheno-hunting a seed batch of Blueberry for blueberry flavor, you want to pick the plant/phenotype that’s aroma is and taste has the most pungent blueberry like qualities.

How Do You Start a Pheno-hunt?

It's best to start a pheno-hunt with a specific goal you are trying to achieve. Something like, “I want the flavor of Blue Dream with the potency of this Fire OG Kush.” You just need the seeds and a goal to get started. 

Can you Pheno-hunt Feminized Seeds?

In most cases feminized seeds will produce plants with enough variation between them where pheno-hunting will be required to select the best possible representation of the strain or cross.

Can you Pheno-hunt Clones?

Technically, clones will all be the same genetically and phenotypically, so there would be no point in trying to pheno-hunt a batch of clones from the same mother. When you receive a clone you are assuming that the mother it came from was selected in a pheno-hunt as the best possible representation of that strain.