Chapter 15: Breeding
A cannabis breeder will usually breed in order to strengthen and purify a strain, combining traits, or improve a certain characteristic such as potency, aromas, higher yields, and other things. When growing and breeding, you need to know exactly where the seeds came from and their genetics. If the breeder of the seed is unable to provide you with a detailed history of how the seeds were bred or what they may have been crossed with, you aren’t going to know what you’re going to get.
Breeding is a fundamental process of growing cannabis. Most of the time, breeding is done on a commercial scale and is very technical, but as the legalization of marijuana increases, as does the popularity of breeding. You can do it yourself if you want.
Propagation of cannabis tends to be a complicated and lengthy process that will take many years for a person to understand and many more to master. However, a home grower doesn’t have to view it as so complicated if they are only looking to breed for their own use. We’re going to look at breeding for the home grower.
Why Home Growers Should Breed
Why is breeding cannabis at home such a big deal? For one thing, breeding gives the home grower a chance to grow new hybrids and conserve their current stock. This will help to strengthen and preserve some genetics for future uses. If a home grower has a strain that they like, then breeding is a great way to gain new crops with those genetics.
One the other hand, those who a simply looking to make sure they have seeds for the next year will see breeding as a sustainable choice to keeping those plants growing. Not everybody is going to be able to head back to the seed company or nursery to buy new seeds every year. After all, a single seed can cost more than $20, and a dozen can easily set you back more than $100. For those without a huge budget, breeding could be the only way that they can keep a plant around.
Breeding Basics
A cannabis plant is either male or female. Cannabis consumers tend to be focused on the female plants since they are the ones that produce the buds we all love. But the male plants are important during the breeding process, as they have to pollinate the females.
For example, the Super Lemon Haze strain is a cross, or hybrid, of Lemon Skunk and Super Silver Haze. One day, a grower decided they enjoy some aspects of Lemon Skunk and some of Super Silver Haze and chose to mix them.
In order to accomplish this, you have to a male of one strain pollinate a female of the other. After the plant gets pollinated, it will produce seeds that contain genetic markers from both plants involved in the pollination. You harvest the seeds and then grow them separately. So which do you pick for each strain, the male or the female?
According to Nat Pennington from Humboldt Seed Company, the female plants tend to carry over more traits than the male. The traits of the male plant, though, tend to be obvious to the experienced grower, so you should make sure that you pick a male plant that is going to complement the traits of the female. That’s why the breeding process has to be intentional to be successful.
How Cannabis Is Breed
After the parent strains have been picked out, the male and several females are placed in a breeding chamber together to contain all of the pollen. The breeding chamber can be as basic as an enclosed space with plastic sides, or it can be a specially designed chamber for large-scale breeding.
One male plant is able to pollinate tens of females. This is why you should only have one male plant involved during the pollination process. This process is intentional breeding. Growers who have accidentally grown a male plant amongst their females and it pollinates a crop will understand that a single male plant is able to easily pollinate hundreds of females, filling the entire crop with seeds.
Once the plants are placed in a breeding chamber, you can allow the plants to grow through the vegetative phase for a couple of weeks to let them grow bigger, but you don’t have to do that. You can place them in a flowering light cycle of 12/12.
A male will grow pollen sacs once matured, which happens during the first couple of weeks during flowering. Pollen gets released and will land on the female plants as the air moves it. When you have an enclosed breeding space, you can contain the pollen so that you do not have any outside pollination going on.
You can also help this pollination effort by simply shaking the pollen onto the females, or collecting it and applying it directly on the females. The pollinated female plants will continue to grow and flower, and they will grow seeds and buds. The seeds formed will have the genetic makeup of both of the parent plants.
Once the seeds are matured, they will be harvested and stratified. Typically, the harvesting of the flowers will happen three to four weeks before seeds are harvested.
Phenotypes
Most hybrids that you can buy have been put through several breeding rounds to help strengthen the genetics to make sure that the descendants of the hybrid will remain consistent and healthy. Look at it this way. For example, you and your siblings hold different attributes that you got from the same parents. This just like the seeds you produce. Every seed that is created from each round of cross-pollination will have slightly different attributes from their parents. The seeds with various expressions are known as phenotypes.
The plant that creates a set of phenotypes with lots of variety is called heterozygous. When it comes to cannabis, you need to have seeds that are homozygous, which simply means that all of them hold the same genes. Homozygosity keeps the plants producing the same seeds with the same makeup.
Once a strain is crossed, the breeder will have to select the phenotype of the strain that they prefer. With large-scale growers, they want to pick the best phenotype for mass production.
Backcrossing
Things don’t stop there. Once a phenotype has been picked out, they will backcross them to help improve their genetics. Backcrossing basically means that you will cross-pollinate with a parent or the new strain itself, simply inbreeding the plant. This will make the strain even homozygous and will help to strengthen all of the desirable traits and helps to ensure those traits will get passed down.
Limitations for the Home Grower
Home growers tend to be limited by space and the number of plants that they are able to grow. This means you can’t easily breed several plants at once, but with some forethought and planning, you can work around the issues. You have to adapt to these limitations
Simple Propagation for Home Growers
Despite the roadblocks you may have, this simple propagation technique can be used to help the home grower breed their own seeds.
You are going to need:
The first step is to sanitize. You have to make sure that you are working in a sanitized and clean environment. Start by cleaning the isolation chamber for receiving the female plant. This clean space will help to prevent cross-contamination and give you a sanitary and safe place for the plant to mature. Diluting some isopropyl alcohol or bleach into water is good enough. Also, you need to sanitize your pollination tools, such as your paintbrush.
You should make sure that your isolation chamber doesn’t have any female plants that you don’t want to breed with. This will make sure that you don’t have any unwanted cross-pollination. However, if you have more than one female plant that needs to mature in this same space, you can implement some of the following selective pollination techniques.
Next, you will start to collect pollen. The pollen sacs appear during the first couple of weeks into the flowering phase. A little while after that, they will open up, and you will have access to their pollen. After you have picked out the best male plant, make sure that you have it separated from all of your other female plants. You want to collect pollen from the plant without accidentally pollinating a bunch of other female plants.
You should make sure that the male plants are always kept in isolation to make sure that your female plants don’t end up getting pollinated when you don’t want them to. Through the use of a small paintbrush, you can carefully brush the pollen off into a glass jar or plastic bag.
You have to remember that pollen is “alive,” and any type of humidity can affect the pollen’s viability. Pollen can be stored in an airtight container and placed in the freezer for a long time. If you know you are going to be using the pollen often, then you may want to keep it stored in the fridge as the change in temperature won’t be as drastic as it would from the freezer. Pollen that is properly stored can last for more than a year.
Once the female plant is in bloom, it is mature enough to receive pollen after the flowers start to form a hair-like stigma. The object of this selective pollination is to put the pollen you collected onto a certain branch or cola that you want to produce seeds on. You can get around a hundred seeds from every cola if they are pollinated correctly
Choosing the branch you are going to pollinate is all up to you and what you want to get from the breeding process. One pollinated bud can yield 20 to 30 seeds. To finish up this process:
  1. Make sure that you have negative pressure in your isolation chamber before you continue.\
  2. Start by getting the container with the pollen, some gloves, and a paintbrush.
  3. Gently collect a small portion of the pollen from the bag with the brush. You don’t need much because a little goes a long way.
  4. Run the brush gently across the female flowers you want to pollination, making sure that you just brush across the tops of the stigmas.
  5. Once it has been pollinated, carefully place a bag over it and then tie it off to create a seal. This will keep the pollen from pollinating other colas on the pant. This does not have to be done if you want to pollinate the entire plant in isolation, or you don’t have a problem with finding a few seeds throughout the rest of the plant.
  6. To prevent contamination, keep the isolation chamber sealed during the plant’s maturation process.
You need to repeat this application process one to three times over the course of a week or two. After the plant has reached its fourth week of flowering, you can quit the application process. If you need to reintroduce the pollinated plant to your grow room with non-pollinated plants, you can rinse it down with a bit of clean water to get rid of excess pollen0. This is not completely fail-proof, but if it is done correctly and carefully, it will help our plant to breathe better.
Seeds are mature once the plant has gone through the entire growing process. You have to make sure that you let your plant go all the way through its life cycle before harvesting the seeds in order to make sure you get the best seeds.
After you harvest and dry your plants, it will be time to collect your seeds. Matured seeds are going to be dark in color and have a striped pattern all over the shell. If you executed this process correctly, you should have a high number of seeds no matter how many colas got pollinated.
For the home grower, the process can simply stop here. You have new seeds to grow more plants with for the following year. Unless you are looking to get into the big leagues, you don’t need to worry about picking out a phenotype or backcrossing.