Cannabis Cross-Breeding and Pollination: How to Create Your Very Own Strains

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So you’re interested in creating your own cannabis strain? Most cannabis growers want not just to grow different strains but to have their own, a strain that will bear their name or a strain that they can call whatever they want.

Indeed creating their own strain is every grower’s dream and we’re sure that it’s also yours too. We have a detailed guide to help you make your strains. But this is not just about growing this strain and crossing it with another. You need to understand the basics of cross-breeding and pollination so you can efficiently and skilfully breed different strains.

Why Make your Own Strains?

But why grow new cannabis strains? Because every new cannabis strain created has the budding potential to create a better generation of strains. Just think of the possibility of growing a new strain which can grow more buds with an have an exquisite taste and aroma? How about a strain which will be resistant to disease or mold, perhaps? You are on the road to creating a super strain when you make your own.

So many strains these days have different effects compared to popular strains from many years ago. By learning how to cross-breed cannabis, you can create better strains compared to what we have today. You may also use landrace or heirloom strains, combine them and create a completely new strain which no one has ever seen or tasted.

Every strain is different. When you grow seeds, the result would have a combination of traits coming from each parent plant. As a variety of plants are bred, breeders can choose to breed their favorite plants. A new combination with unique effects may be created.

And as you grow generations of plants, picking the best plants for growing new seedlings will show specific traits that you want and less of those that you don’t want to have in cannabis. This continuous breeding and picking are how breeders create new and impressive strains.

What to look for when breeding new cannabis strains?

There are some important things to consider when breeding new strains. Consider that there are numerous breeding combinations which can create all kinds of strains but every breeder has a specific goal in mind.

Breeders look for growth patterns and hardiness. The growth pattern of a plant refers to the overall appearance of the plant including its height, shape, density, and bushiness. It also covers the harvest time or how long the plant takes to flower and the number of yields indoors or outdoors.

Breeders also look for hardiness which is about the plant’s ability to survive indoors or outdoors. It is how quick plants grow, its resistance to molds or root problems if it can stand temperature extremes and many more.

The appearance of the buds also matters. It is all about the smell, color, potency, possible effects and the number of cannabinoid compounds including THC and CBD.

Take note that the bigger your genetic pool is, the easier it would be to look for traits which you want to include in breeding new plants. Consider modern breeders as lucky as they can choose from a wide variety of strains. They can create better strains or at least create strains that have the characteristics that they need in cannabis plants.

A breeder’s dilemma

But despite this impressive spread of genetics waiting for a regular grower, it’s impossible to grow a large number of plants at a time. This is where expert breeders come from. They will be able to create new and exciting strains which have the best characteristics coming from their parent strains.

If you were to grow and breed a small number of plants then this won’t be a problem even for a regular grower. He may use small strains which are perfect for growing in small, limited spaces.

All about growth patterns in plants

Growers usually pay attention to how their plants grow because plant growth can determine if the plant can survive indoors or outdoors, in different climates, how fast the plant flowers and more. Plant growth is measurable and mostly information about different strains are available online.

Breeders have different preferences when it comes to plant growth and mostly, it has to do with their growing conditions at home. For instance, growers who are located in a country or state where cannabis is legal may prefer plants which can grow taller like sativas. These plants may grow and veg out outdoors and hence may provide more yields.

Same goes with a grower who lives in a country where cannabis is prohibited. This grower likely wants a strain that is compact but dense. To compensate for the lack of space and limited growing conditions indoors, he may want a plant that will yield more despite being small.

Flowering times are also very important. Growers would prefer a strain with quicker flowering times so that they could harvest fast. All these favorable characteristics when it comes to cannabis plant growth pattern may be considered when creating new and better strains.

Consider plant hardiness

Most impressive plants with good yields, faster flowering, and nice effects may have one flaw: they are susceptible to molds and diseases. This is also the most common worry of cannabis growers and breeders. Molds and mildew, as well as plant diseases, can affect the growth, development and the survival of cannabis plants.

Breeders look for ways to deal with molds and diseases researching for strong and hardy plants and combining their genes. This is a very tough trait to breed but most breeders are successful over time.

Another characteristic that determines the hardiness of plants is their ease of growing. A hardy plant can withstand the care of first-time growers. This plant is easy to grow and can bounce back to good health despite missed watering, incorrect feeding or occasional molds and pests.

You might think that this is again some kind of super plant that breeders are looking for but in fact, these plants already exist. If you look for cannabis strains that are easy to grow, you’ll find these new strains which are indeed able to grow easy with very little care and attention. Take note that marijuana was roadside weed plants after all!

All about the buds

Now, this is where cannabis breeders take so much time. They want plants that can grow buds and aside from this, buds that have the characteristics that they want in weed. Consider that every grower is different and hence may have his preference when it comes to weed, it is thus very common to find new strains with a wide variety of traits.

The smell/aroma of the buds is one of the most common traits that parent plants pass on to their children. The smell of a parent can be combined with the aroma of the other parent creating a complex yet unique product.

This is the reason why most strains don’t just have one smell or a particular taste. Most of the time, it’s an explosion of aromas and tastes, a dominant smell and an aftertaste that lingers. And you can combine your favorite smells and tastes as long as it does not contradict the result. For instance, a fruity, citrus and tropical taste and smell mostly go hand in hand but if you were to add spicy or diesel to the mix, it would not be as pleasant. But again, this all depends on your preference or what you look for in a strain.

The color of the buds is one of the most interesting and mostly the most challenging characteristics that breeders try hard to breed. Most breeders are in love with different shades of cannabis including gold, red, blue, purple and orange colors on their buds.

The different colors are due to pigments similar to chlorophyll in plants and usually, these are triggered by exposing flowering cannabis plants to lower temperatures. But it’s not as easy as it may sound because this is usually a recessive trait among cannabis plants. It can take generations of breeding before the right color emerges but there’s no reason not to try.

The potency of the buds is another trait that breeders are questing for. Most breeders don’t care much for the size, yield, appearance and the growth patterns of plants as long as they get potent buds. Breeders say that this is a tricky trait to breed.

It seems easy to breed potent buds; as easy as taking two, three parents and mix their genes up and voila. You also need to consider if the potent effects may affect the growth of plants, flowering, and yields. You just can’t be irresponsible and just take two and two without considering other factors.

The potency is also considering the amount of THC, CBD, CBN, and other cannabinoid compounds. It considers the recreational and the therapeutic effect as well as the side effects of the plant. This is possibly the most important factor that drives breeders to create better strains.

What is selective breeding and why is it done?

Over the past years, most growers are looking for high THC strains, strains with very potent psychedelic effects. They want strains with dense buds, big yields, quicker flowering times, stunning colors and potent flavors. Quite recently, a large number of breeders are carefully cultivating cannabis with high CBD or medicinal strains.

But aside from the amount of CBD or THC in a strain, there is so much more when it comes to the overall effects of marijuana. Hundreds of cannabinoids and terpenes have not been studied or even discovered and these chemicals can cause changes in the buds that will be produced.

Some growers are also starting to breed using other traits aside from color and the THC or CBD content and paying higher attention to the differences in strains as well as the effects.

There are some growers and breeders love the strains that they enjoyed back during the 1960s and 1970s and have recreated these strains. These classic strains may not be as potent as the strains we have today but the effects are more pleasant to some people.

Lucky for these breeders and growers, a lot of seed banks online have preserved landrace or heirloom strains. They can get their supplies from these retailers.

All about landrace and heirloom strains

You must have heard about a popular cannabis-based TV show featuring strain hunters looking for hard-to-find landrace strains. The hosts travel far and wide to look for landrace strains braving forests, woodlands, and even dangerous jungles to find plants and seeds.

This is a perfect description of how breeders look for landrace strains. Landrace strains are locally-cultivated cannabis strains which may have been developed by locals in an area. Some landraces are completely untouched by humans and because of this lack of intervention, the plants have preserved their natural traits.

A very eager cannabis breeder or grower may travel far, as far as the country of origin of a specific landrace to get genuine seeds. Sometimes they find landrace strains with new and desirable characteristics that they have never seen before like smell, taste, color or potency.

A breeder may take home several seeds to grow themselves. They may also take cuttings or clones of these plants. Landrace strains have stable genetics and have strong potent effects. Just some of the most popular landraces are Panama, Columbian, Afghani, Thai and many more. Usually, there will be so many phenotypes that will come up when you mix heirloom strain.

What is a ruderalis plant?

A ruderalis plant is a type of cannabis plant that has unique characteristics than its sativa and indica siblings. The ruderalis is a superstar in most breeding farms and gardens because this has impressive traits which can transform an ordinary strain into something extraordinary.

A Cannabis ruderalis plant is not a landrace plant because it is not actively cultivated by locals but instead it is a local plant used to make different strains. Ruderalis plants are blessed with autoflowering characteristics which means these will flower without the need to be exposed in a special light schedule.

Compared to photoperiod or regular plants which will flower only when exposed to a 12 hour light and 12-hour daylight schedule, ruderalis will flower when the plant is mature which is at only 7 to 9 weeks. Another unique characteristic of ruderalis strains is the size of the plant.

In the wild, ruderal is plants are tiny, scraggly and have very small yields. These grow in very cold places with very short summers and hence these plants have very minimal foliage with only a few buds.

When a ruderalis strain is combined with a regular strain, it will pass on its prominent autoflowering traits to its children. Actually, ruderalis strains have no use to growers who want to cultivate more weed. This plant is not for dried flower or concentrate making and are only used to create autoflowering plants.

Original crosses of cannabis ruderalis plants have refined and stabilized so many different strains. Over many years, many breeders all around the world are working together to isolate the automatic flowering trait which produces very potent buds and create big yields. By tirelessly breeding the ruderalis strains with potent regular strains, there are now strains that have kept the potent auto-flowering characteristics while the unwanted characteristics were removed or breed out. Usually, these are phenotypes that did not provide good buds or had irregular growth patterns.

You will also find stabilized autoflowering strains that have kept their beauty as well as their potent effects. Some breeders have also created hybrid versions of their beloved regular strains. Therefore, all the favorite effects and traits they love has become an autoflowering strain which can flower quickly and have smaller and denser structures.

Important terms to remember

To cross-breed and create new strains, you need to understand some important breeding terms.


A phenotype is similar to traits or characteristics that children get from their parents. Each child is a phenotype with different characteristics. Take an example: you are a phenotype of your parents as much as your brothers and sisters. You have unique traits that your siblings may not have.

Two parents, one tall, one short have kids. Their kids may be short or tall. But if both the mother and father are tall then chances are, their kids will be tall as well. This is how plants phenotype work.

There are also unstabilized strains which may have one or more phenotypes. This means, you can work with two plants in one strain and this can show different phenotypes. These plants may look completely different from one another.

On the other hand, some strains are stabilized which means the seeds coming from this strain have the same phenotype. Regular plants grow this way. Breeding stabilized plants is done by intensive breeding to make sure that the seeds only have genes for the ideal phenotype.

However, plant genetics is not the only factor that may affect how plants grow. Genes and environmental factors play an important role.

If you take a cutting of a plant which is the exact copy of the original plant, these will grow very similar to the parent plant when grown in the same environments. But when the cutting is grown in a completely different environment than its parent plant then expect different results.

If one environment is cooler, growth may slow down or in extreme situations, this may even kill the plant. This same plant may survive better when grown in warmer environments. Consider too that some cannabis plants will grow well even in soils with lower nutrient levels but will suffer from different problems when grown in soils with higher nutrients. This trait is according to the genetics that it has inherited from parent strains.

A successful breeder will understand the environment that a strain needs to be able to grow better. He knows what it takes to get the most out of a strain.

Dominant and recessive traits of strains

Two terms often used in breeding cannabis strains are the terms “dominant” and “recessive” traits. Dominant and recessive traits are characteristics of plants that may be hidden and these may not be seen until you combine two plants which have a copy of the recessive gene.

You take two plants with green buds however, some of their children may grow pink buds. This could mean that one of their parents may have genes that can grow pink buds. This unique recessive trait was carried on to their kids.

Understanding basic genetics will provide you with an edge in any breeding project. The first thing to know is all plants and animals have two versions of every gene taken from each parent. The combination and interaction of the two genetic versions can create unique effects on the plant or animal.

Specific genes are very dominant which means these will always show no matter how many generations of breeding. A plant will always have this trait even if it has only one version of the gene. Meanwhile, recessive genes can only be seen if a plant gets two copies of the recessive gene coming from both parents.

What is complete dominance?

If cannabis plants have two versions of a gene that deals with bud color, the darker version is dominant while the lighter one is recessive. This means that the plant can have buds that are lighter or darker and will never mix these versions.

If a plant carries any of the copy of the dominant gene, then the buds would have a darker color. Meanwhile, the buds will only have a lighter color if the plant gets 2 copies of the recessive gene.

While this is the ideal setting, most of the time, genetics will not follow this rule. Not all genes may follow this dominant and recessive condition or the case of a gene being on or off. Genes may also interact with other genes to create unique combinations. Usually, certain characteristics may be developed during the interaction of so many genes creating more confusion.

What is incomplete dominance?

Let’s go back to the previous example with two plants, one with darker buds and one with lighter buds. In incomplete dominance, both genes have incomplete dominance- the resulting strain will have not just one version but a mixture of the two parents. When a plant gets one recessive and one dominant gene, it will have darker buds since neither version is dominant. The two parents influence each other resulting in a combination of the two versions of the trait or gene.

With incomplete dominance, the first generation would have darker flowers considering that all of the offspring would take a version of the gene. When two F1 plants are crossed, you will only get 25% chances of having darker or lighter buds and around 50% chances of having dark buds.

But aside from the color, other traits also matter like the smell, aroma, taste, effects, etc. The key is to discover recessive genes in your plants’ gene pool. The trick is to initially cross starting plants. After a successful cross, combine their offspring or do a backcross with their parents to see if new genetic traits start to appear.

After seeing recessive traits, identify the ones you want to keep and the traits that you want to discard. This time, you can now cross plants with other members from its family. Do this until you have found the plants you want to cross together so that their offspring will always show the specific trait.

As you continue to breed selectively, you will soon be able to create a wide variety of characteristics from your breeding stock. If you’re interested in learning more about plant genetics, you can use a tool called a Punnett Square. This will help you identify and predict a particular cross.

All about back-crossing, inbreeding and stabilizing strains

Meanwhile, a stabilized cannabis strain will give you consistent results from all seeds. To achieve this, you need to tweak your breeding stock using breeding and something known as back-crossing. This is done until you have a set of parent strains which can consistently create offspring that will have the same characteristics – just like getting clones in seed form. When you use a stabilized strain you will know exactly what you will get.

Another method is back-crossing which is an effective and highly-efficient technique to stabilize strains. This method is all about taking a plant and crossing this with one of its parents or a closely-related member of its family. The goal is to create an offspring that’s completely similar to its parent. Each one of the offspring will have two versions of the desired genes from the parent.

Backcrossing works this way: if you have two plants and the mother has a trait you want to breed like high THC content. You can take one of her male offspring and cross this back to the mother to get an offspring that will be more like the mother. This is because the resulting plant has two versions of her genes, therefore, it will be able to pass the high THC trait to the next generation of plants.

There is such a thing as heavy back-crossing which is a method that leads to heavily inbred strains. This method can cause recessive genes being locked in or too difficult to come out even after many generations of breeding. To make it simpler, this is inbreeding gone wrong.

A good thing about in0breeding is you’ll get healthy and uniform cannabis plants which will create offspring with consistent genes. A perfectly inbred plant is called an asset to the program because all the traits it has been predictable and will be passed on to generations

Heavily-inbred plants come with two similar versions of their genes and will consistently pass on their specific version of the gene to all their children.

So when do you back-cross your plants? If when breeding, you like the way a plant grows or looks then you may perform a back-cross. If you are trying to preserve certain traits then you must backcross. This is simply grooming a plant to be more like its parent. This also ensures that the traits you want will be passed on to the next generations. You only need to backcross once or twice to achieve the genetic stability you need.

Selecting the best male and female plants

Female plants should be plants that grow well, with buds that are in good shape and has the effects you’re looking for. But if the female plants that you’ve grown are not the ones you’re looking for, try again.

This is indeed an easy way to select the ideal female candidate but some expert growers go the distance and cross the chosen female plant with itself.

Through the process of feminization, you back-cross the plant with itself which is more effective and a lot quicker than back-crossing it with its offspring. Some growers will cross two female plants, overlooking the process of using males.

However, some breeders are not in favor of feminization as a part of breeding because forcing female cannabis plants to grow pollen sacs for the process of feminization may be unintentionally encouraging hermaphrodites. Some growers recommend using males in breeding new strains because they believe that males are a part of long-term breeding.

Breeding males and checking its offspring is very important because it’s only this way that you can identify specific male plants that will work well in creating particular traits in their female children.

Meanwhile, male plants are considered the most important components of breeding. Males are known as the carriers of genes that create buds. But the only way to know for sure if the male carries the genes that it will pass on to its offspring is to cross it with a female and see the results. Usually, growers and breeders can create or look for a male plant that will provide desirable characteristics to their offspring.

Even if a male plant does not produce flowers, it can still pass on traits that can grow larger, denser buds with flavorful scents and aromas.

Instructions on How to Breed New Strains

Here is a step-by-step way to create new cannabis strains. Keep in mind that you will be growing different generations of plants so be sure to tag your plants so you won’t lose track. We recommend color tagging your plants so you’ll easily identify the different generations of plants you are growing.

  • Select male and female plants

The very first thing you need to do is to identify the male and female plant you will use. Your parent plants must be healthy, growing new leaves at least every day and should be drinking and eating well.

Take note of the appearance, growth pattern, hardiness and other traits you want your new plants to possess.

  • Separate your male and female plants

Before your plants start to grow pre-flowers, isolate each. You need to keep males separately from females because of the following reasons. You must isolate females so your chosen male will be the only one to pollinate your females. You are to isolate males so you can successfully harvest pollen only from the plant, no contaminating pollen coming from other male plants.

  • Get pollen from male plants

The males will soon grow sacs or buds along the junctions between the stems and branches. Wait till these crack open to reveal the pollen. Collect this in a small plastic bag. You may use this pollen right away or freeze it to be used later. Breeders, however, recommend using fresh pollen instead of old pollen because this is more potent.

  • Pollinate female plants

From the room or cabinet where you stashed your female plants, turn off fans and close all windows and doors. Open the bag that contains the pollen and use a small brush to apply pollen to the flowers. You may also place the pollen in small bags and use this to cover the buds. Seal this with strong tape but be careful not to pick your buds. Leave this on for about two hours.

  • Take good care of your newly pollinated females

Your pregnant mother plants need special care. Provide plants with the right nutrients. During this stage, your plants need nutrients with nitrogen, potassium, phosphorus and other micronutrients. Seeds will start to form after a few weeks of pollination.

These will want to get out of the calyxes a few weeks after. After harvesting, keep your seeds inside a canister and keep these in a cool and dark place. Never freeze these.

  • Plant seeds

It’s time to germinate your seeds and grow them as you would new plants. Use good lighting, the right humidity level, and good soil when growing your plants.

Whether you’re growing these in soil or using hydro, make sure to keep clones of your plants. This will start your breeding collection. Do this for all the plants you will grow.

  • Take note of your progress

Meanwhile, keep track of your plants. You can simply write down your progress or it would be better to create a kind of growing diary using your computer. Use a good digital camera and take photos of your plants. Take a photo of the buds, seeds, stems, and leaves. Use a measuring tape to measure plant height and other stats.

If you want, make a time-lapse video of your growing and breeding projects. After a successful program, share your success. This is the best way to help people who are also learning how to breed cannabis for the first time.

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