A Breeder’s Guide to Pheno Hunting

The development of a grower isn’t always linear, but there is a distinct turning point when one goes from just growing seeds to making selections and keeping mothers. Hunting seeds is awesome, but where’s the fun in finding something awesome if you can only ever flower it out once?

This article assumes you already keep mother plants and grow from cuts, rather than just flowering out seed plants each time. If you’re still hunting through seeds, I strongly recommend reading up on the benefits of keeping mother plants and how to get started.

Grow Space & Logistics

This section covers topics like space management, cloning, plant management, and more.

You’ll Need Extra Veg Space

When you take cuts in late veg or early flower, you’re going to need to keep those plants around until after you’ve dried, cured and properly sampled your flower. That means holding onto your clones for potentially a month and a half or more before you can make a meaningful decision about the plant.

Always make sure you have enough veg space available to house those cuts until you’ve managed to get a good sample of your flower.

This is one of those things that can catch new pheno hunters out. It’s easy to think about the flowering space required for your hunt, but forget that every plant you want to keep needs somewhere to live while you decide whether it deserves that space.

Monster Cropping For Space Management

Monster cropping is the process of taking clones from flowering plants. These clones have to transition back into vegetative growth, which can result in unusual growth patterns and a strong increase in lateral branching once they recover.

The idea for many growers doing this is increased branching and yield, but I strongly recommend it for pheno hunts with limited space.

Instead of having your clones growing vigorously by week 4 of flower in your main flower area, you can keep them in a kind of stasis for several weeks. I’ve found that by taking clones in week 2 of flower, I can successfully complete my pheno hunt before I’ve even needed to pot up my clones from their solo cups.

They will stay small with some strange or delayed growth for a while, so don’t expect a quick turnaround time. The idea here is delaying growth until you can sample your plants.

The exact timing and response will vary between plants, so treat monster cropping as a space-management tool rather than a guaranteed method of keeping every clone small.

More Plants, Smaller Pots

The mind of a production grower and a pheno hunter is inherently different. Production growers want to maximize yields and are often happy to sacrifice some time to achieve that. Pheno hunters who are trying to look through as many pools of expressions as possible don’t usually care too much about yields, because at the end of the day you’re just trying to know which genetics to toss and which to hold onto.

Smaller pots with more regular irrigation can significantly increase the number of plants one is able to look through. And it’s much better to look through 20 plants that yield 10 grams than 5 plants that yield 40g each, if your focus is selection.

Just remember that the goal isn’t to deliberately stress plants into producing poor-quality flower. You still want every plant to receive enough root space, light, nutrition and time to give you a reasonable indication of what it is capable of.

The more important principle is population size over individual plant yield. If you have limited space, your resources are generally better spent seeing more genetic expressions rather than growing fewer plants to their maximum potential.

Take Backup Cuts

Taking clones is obviously really important, but what if they don’t root? That’s a less-than-ideal situation that many growers would love to avoid.

Instead of just taking one clone off your plant, make sure to take at least 2 (ideally, 4). This helps buffer against errors in the cloning process and allows you to avoid having to reveg your plant.

Cloning success is influenced by both the cultivar and the conditions in which the cuttings are produced and rooted. Research has shown meaningful differences between cannabis cultivars in rooting speed and success, while factors such as the mother plant, environment and cutting characteristics can also affect propagation.

There’s also a simple logistical advantage to keeping multiple cuts: if you have four clones and three root, you have a spare. If you take one and it dies, your entire selection suddenly depends on a plant you were hoping you’d never need to reveg.

If All Else Fails, Reveg – But DON’T Rely on It

If you find an amazing plant you want to keep around but you don’t have a clone of it, you can always try to reveg it. However, people often underestimate the amount of frustration that goes into revegging late-flower plants.

Success can be achieved even with minimal biomass remaining, but watering practices become a real challenge. The plant has very little leaf area and therefore much less transpiration, while the existing root system can still be relatively large. This makes it very easy to overwater a plant that looks like it needs more water.

Some growers will reduce the root mass or pot size to make managing the plant easier, while others simply leave the root ball intact and allow the plant to gradually recover.

Eventually, new vegetative growth may appear, often starting with single-bladed leaves before normal growth resumes. However, the process is unpredictable and can take a long time, sometimes months.

So in worst-case scenarios, you do have one more lifeline. But it’s never guaranteed, and it’s a terrible backup plan compared to simply taking enough healthy cuts in the first place.

Making Selections

This section covers the selection process. What to look for in a keeper, how to make good selections, and how one can use long-term goals to make selections easier.

Allow For A Cure Before Culling

If you’re like me, you dig into your samples before she’s even off the drying rack. But hold off a few days before making your selections.

Freshly dried flower can change noticeably during the first part of storage as moisture redistributes and volatile compounds continue to change. Some growers prefer a much longer cure, but giving your samples at least several days in a stable jar will generally give you a much better indication than judging them immediately after drying.

I’d also recommend making your first notes early, and then coming back to the samples again later. A plant that smells incredible immediately after drying may not be the same plant you’re still excited about after a few weeks.

The important thing is consistency. If you’re comparing 20 plants, try to sample them at roughly the same stage of drying and curing rather than judging some immediately and others weeks later.

Keep Selection Notes

This is one of the easiest things to overlook when hunting a large population.

By the time you have 20 or 30 plants in front of you, it becomes surprisingly difficult to remember exactly why Plant #7 was interesting three months ago.

Give every plant a number and keep simple notes throughout the run. Things like structure, stretch, flowering time, resin production, aroma, density, disease resistance, ease of trimming, yield and smoke quality can all become useful later.

You don’t need a complicated spreadsheet. Even a basic scoring system can help prevent your memory from becoming the deciding factor.

And ideally, make your notes before looking at what other people thought about the plant. If you know which plant everyone else thinks is the “keeper”, it becomes very easy to talk yourself into liking it.

Determine Your Breeding Goals

Pheno hunting doesn’t need to be about selecting breeding stock. Sometimes a clone is just a production plant. However, if you’re breeding, having a direction can significantly improve your efficiency.

Collecting ‘nice’ strains is difficult, just start with some good genetics, and you’re bound to find some winners. So having an idea of what you’re looking for means you can narrow down your selections more quickly.

If you’re looking for a production clone, you might care most about structure, yield, flowering time, resin and ease of growing.

If you’re selecting breeding stock, you may care more about a combination of traits and whether the plant helps move the next generation toward your goal. These are not necessarily the same thing.

A plant can be an incredible smoke but a poor breeding choice. Likewise, a plant with an average-looking flower can be extremely valuable in a breeding project if it contributes a trait you are trying to preserve.

Sometimes You Just Have To Let Them Go

“Make aggressive selections” is a good tip to ensure strong genetics with positive traits proliferate over mediocrity. But when you’re actually hunting, it’s easy to want to keep a plant just because it has one special trait.

If one is working with a large space, there may be merit to holding onto some unique outliers. But be conscious of the negative traits you’re allowing into your gene pool because you just like one specific trait.

This is particularly important when breeding. If a plant has an amazing terpene profile but consistently exhibits poor structure, weak growth or another trait you really don’t want to reproduce, you need to decide whether that one special characteristic is actually worth carrying forward.

A Good Hunt Can Take Time

Selections are only ever as good as the information one has about the plant and its expressions. And let’s be real, not every run goes perfectly.

You want to make sure that when you do make your final selections, you’ve truly seen the plants in their best, rather than at their worst. Be honest with yourself, ego will just keep you wanting to take shortcuts, and ultimately, the genetics become the victim.

It may take more than a year of running through a large population before you select your final keepers.

There’s another reason not to rush this: a single run is only one environmental snapshot. Cannabis traits can be strongly influenced by genotype × environment interactions, meaning that what you see is the result of both the genetics and the conditions in which those genetics were grown.

A really good keeper should ideally survive more than one round of scrutiny.

Don’t Make Final Selections Without Running The Cut

When you perform a pheno hunt, are you flowering out the seed plant or the clone?

The reality is that plants can behave differently depending on whether they are grown from seed or from a cutting, but it’s important not to oversimplify this as being purely due to “hormone distribution.” A seed-grown plant and a cutting can have very different physiological histories, root systems and plant architecture before they ever reach flower.

A seed plant can only give you one opportunity to see that individual expression under those conditions. But if you select it as a keeper, the rest of that genetics’ life will normally be run from clone.

So the final test should be the cut.

One approach is to do an initial hunt from seed, which lets you see the range of expressions within the population. You can then make some early selections and take cuts from those plants. The promising selections can subsequently be flowered from clone, allowing you to see whether they actually perform as a repeatable production plant.

This is a much better way of thinking about a pheno hunt than assuming that the biggest or best-looking seed plant automatically makes the best clone.

Consider Phenotype Variance When Selecting

A plant’s phenotype is the collection of observable traits produced by its genetics interacting with its environment. It isn’t simply what the plant “looks and smokes like” in isolation.

Grow the same cut under two distinctly different environments, and you can end up with differences in how it grows, how much it yields and potentially its chemical profile. Research has demonstrated environmental effects on cannabinoid and terpene-related traits, while genotype also plays a major role.

This is why growers can sometimes have very different experiences with the same clone.

A clone selected under extremely high light, tightly controlled environmental conditions and a particular feeding regime may not perform identically in a home grower’s tent. That doesn’t necessarily mean the clone is bad, it means that the environment is part of the equation.

This becomes especially important when selecting plants for a particular type of grower.

If you’re selecting for high-input indoor production, select under those conditions. If you’re specifically interested in organic soil growers, it’s worth doing a first-hand look at how your selections perform in that medium.

The closer the selection environment is to the environment in which the plant will ultimately be grown, the more useful your selection becomes. And if a plant performs exceptionally well across multiple environments, that’s even more interesting.

The Goal Is Repeatability

Ultimately, a pheno hunt isn’t just about finding the plant that looked the best once.

It’s about finding the plant you still want after you’ve removed as much guesswork as possible.

Take enough cuts. Give yourself enough space. Sample properly. Keep notes. Be willing to kill plants you like. And most importantly, run your best selections again.