Cannabis Plant Phenotypes And Pheno Hunting Explained
The cannabis plant has evolved over thousands of years and can express an extensive range of aromas, colours, growth patterns, flowering times, yields, cannabinoid profiles and effects when consumed. Cannabis seeds contain some of this variety, making each individual cannabis plant slightly different. These different varieties within strains are called phenotypes. By growing many seeds, a grower can look for a specific male or female phenotype and keep their favourite version of a strain.
The O.G. Kush on the left has much more leaf than the one on the right. Looking through sites like Leafly, you can see that every plant grown from seed is unique.
A Good Example
A phenotype is a collection of traits that cause a cannabis plant to be different from the others. You may be growing a strain from seed that is a hybrid of two other strains. Crosses like this often end up with different phenotypes that look more like one parent than the other.
This is the same variation that causes children to look more like their mother or father. When growing cannabis seeds you may notice vast differences between the seedlings after a few weeks. Strains with little to no variation are often described as “stable” strains.
We’ll take any excuse to use cute animal pictures, but this is a good example. The kittens in this litter are all from the same parents, but still look different: they all have different phenotypes! You could say that this “strain” of cats is not very stable.
In most early hybrids, some plants are taller and have leaves that are more sativa in appearance, while others might take more after their indica parent. You may also be able to notice a difference in aroma between plants from the same batch of cannabis seeds.
Hunting Phenotypes With Cannabis Seeds
One exciting part of cannabis cultivation is what is called pheno finding or pheno hunting. This simply means you are looking for the best individuals within a group of plants from the same strain. The “best phenotype” is completely dependant on what you want as a grower, and can depend on any trait you think is important.
Desired traits are often not expressed by a cannabis plant until they start flowering, so clones are usually taken before any of these traits show. Clones should be carefully labeled, so that they can be grown out or discarded later. If you are looking to breed shorter plants for example, you would only keep the clones of your shorter cannabis plants. Generally however, selection revolves around growth speed, yield and resistance. Once you know what you’re looking for, you will know immediately which of the plants you will not want to keep. These “runts” are usually the smallest in size and production or the ones that have no significant aroma.
Most of the desired traits are only clear during flowering, but growth rate can be seen from day one. In this test we discarded the cannabis plant on the top right early, as it was lagging behind too much.
Many seed banks and professional breeders will hunt phenotypes from up to a thousand seeds and eventually work their way through selection until they have one or two phenotypes they are happy with. This extensive and laborious process has to take place to make sure only the best genetics make their way to growers.
Important For Breeding New Strains Of Cannabis Seeds
If a breeder did not take the time to find the strongest and best phenotypes around, then new strains may not be as potent or productive as they could be. When using regular cannabis seeds over feminised cannabis seeds, a grower can expect much more diversity. Besides having female and male cannabis plants, the plants will display a wider range of characteristics from the original parental lineage. This is because regular cannabis seeds are bred using two parents, whereas feminized seeds are often bred from only one hermaphrodite parent.
Pheno hunting is always based on selection criteria that the grower or breeder decides are important. Like we mentioned, these criteria often include aroma, growth rate, potency and yield. You can always add more criteria as you go along. It might simply come down to the final yield when potency is similar between plants. When working with a wider range of phenotypes the differences can be much larger.
This picture contains two test reports of the same strain that show the cannabinoid and terpene content. Even though our strains are stabilized over several generations and considered highly stable, you’ll still see differences between plants.
Different phenos can also cause a different experience, like a narcotic indica high with an earthy after taste, or a citrus tasting sativa buzz. Practical differences are also important, as selecting different phenotypes can also be the difference between a cannabis plant that flowers in 8 weeks or one that flowers in 10.
Breeders work with large numbers of different phenotypes, as it allows a lineage of cannabis to really evolve. Many crosses are made to combine the best properties of different strains. Our Gold Bar Kush for example was created to combine the citrus tones of Orange Bud with the taste and effect of our Medical Kush. Crossing the two strains is easy enough, the challenge lies in selecting a phenotype that combines all the best properties of both strains. Every time a cross is made, you end up with a range of different phenotypes to choose from. Once a desired phenotype is found, a breeder has to stabilize this line through inbreeding.
The ability to create new flavours, different effects, change flowering times and growth forms and increase resistances is what makes breeding and pheno hunting an amazing process.
Indica And Sativa Cannabis Plant Phenotypes
It is slightly more difficult to hunt phenos of indica dominant cannabis plants than finding diversity in hybrids or sativa dominant strains. Indica dominant plants are usually flower and easy to grow, so pheno hunting indica strains is often mostly geared towards improving flavour or effect. Indica plants obviously produce many different phenotypes, but some may only stand out once you smell them.
This picture gives a good impression of how different sativa and indica plants look in terms of leaf structure, branching and internode space.
The original UK Cheese for example, was created by pheno hunting based on aroma. UK Cheese was a phenotype of an Afghani Skunk that was selected for the dank creamy taste that is world famous today. Many Kush strains were developed through pheno hunting as well. Kush phenotypes are often selected based on their aroma, adding a little extra flavour to its unmistakable lemon fuel stench. Strains like our Purple Berry Kush for instance are the result of an extensive pheno hunt in which aroma and fragrance were more important than the final yield.
This picture is a simple overview of how you can develop new strains. First a cross is made between two parents, giving rise to a very variable offspring. These seeds are then grown out for the first round of selection, after which the best couple are selected. After a second round of selection, only the best phenotype is kept.
When hunting phenotypes in sativa strains, you will usually see several plants with a realistic flowering time of 13 weeks or more. While taste and smell is still very important, a lot of pheno hunting in sativa strains revolves around the flowering time. Old school haze heads usually don’t mind a logistically demanding strain or spending a few extra weeks growing marijuana. Commercial growers are usually looking to shorten the flowering time as much as possible for a fast turnover.
When growing hybrids you will come across more diversity in terms of phenotypes than with just indica or sativa cannabis seeds. A perfect example of this is K-Train, a cross between Train Wreck and O.G. Kush. When you grow this strain of cannabis, you will find some of the plants will be more O.G. Kush dominant in their size, the leaves, the smell and the stem size. You will notice that other plants are larger in size and grow thinner and lankier, taking more after their Train Wreck parent. When the plants transition to flowering, some plants will also stretch much more than others and the calyx to leaf ratio can be very different.
Different phenos also have differences in growth form: the tall lanky (sativa dominant) plant on the left and the short bushy (indica-dominant) one on the right are the same strain!
How To Find Different Phenotypes
- Look at your plants from a distance and see which one stand out the most and has more of a presence than the others. Then inspect each cannabis plant closely and often and compare them to each other. This means getting hands on and up close to the leaves and stems, trichome production and colour patterns. You can be quite rough with the plants to see which ones can handle stress better or even super crop the main stem are early on to find out which one has the fastest recovery time.
- Check the roots on a regular basis to check which plants are rooting more profusely and which have a stronger root ball. Some plants that look great up top may have a small root ball, while others may have a great root system despite being smaller in appearance.
- Smell the plants by rubbing your fingers around the stems and the undersides of the leaves. A cannabis plant that gives off the most aroma and scent in an early stage will usually be the loudest one in the room by flowering time. Once you have buds growing you will find out for sure which individual cannabis plant has the best smell. Interesting differences can usually be seen the best during flowering, so this is the part where you may find something new.
- Take clones from your plants and number them accordingly. This allows for you to make notes and when selection time comes, you will know exactly which clone corresponds with which final phenotype.
- Our final tip is probably the most important one: select your strongest and most aromatic cannabis plants if you plan on keeping phenotypes around. Yield can always be worked on with growing techniques or breeding, but it is very difficult to recreate a specific flavour or aroma. When you have a cannabis plant with unique flavours that the internet forums go crazy for, you will know your selection process has paid off!
Final Thoughts On Pheno Hunting
We hope this article will help give you a better understanding of the process of pheno hunting and why it takes up most of a breeder’s time and space. Now you know what goes into making a new strain of cannabis seeds and why we’re so proud of the quality we’re able to offer. And whether we’ve inspired you to create your own brand new strain or given you a better idea of what to ask breeders, we wish you good luck growing cannabis!
The cannabis plant has evolved over thousands of years and can express an extensive range of aromas, colours, growth patterns, flowering times, yields,