If you are looking to get the most female cannabis plants from your regular cannabis seeds, this article is for you. Can’t fully get rid of that cannabis strain you grew for so long? Learn how to store seeds and pollen to clear space in your garden and hang onto those favorite genetics for another day.
How to Get More Female Plants From Regular Seeds
Statistically, cannabis produces more male plants than females. Using these techniques can increase the number of female plants grown from regular seeds. Make the most of your time, space, and precious dollars by boosting the number of females every grow.
Unless you are planning on doing some breeding of your own and you’re looking for a perfect male, female cannabis plants are what growing marijuana is all about. However, unless you purchase feminized seeds from a reputable source, females aren’t always guaranteed. In fact, statistically, regular cannabis seeds will produce 75% or more males per crop.
It is impossible to tell if seeds are female or male, and very difficult to tell if a young plant is male or female prior to the plant differentiating. Males do have some differing growth characteristics, but it is not always easy to recognize boys from girls in the vegetation phase.
There are techniques and tricks of the trade that can be used for increasing the likelihood of getting more females from regular seeds. The key words here are a “stable growing environment.” Stress tends to produce more males, and undue stress during flowering can turn plants intersex.
STABILITY IN THE ENVIRONMENT
Stability of the growing environment is essential to increase the female to male ratio. From the moment the seeds are germinated, a growing environment with as few fluctuations as possible is ideal. Stress is the enemy when trying to get females
This is true of all the essential requirements for plant growth. Maintain stable temperatures and humidity. Make sure the photoperiod begins and finishes at the same time every day. Be sure there is no light pollution interrupting plants during the night cycle. Be sure the nutrient mixes are exact every watering. Spikes up or down in nutrient mixes can cause stress, increasing the chance of males.
GIVE SEEDLINGS LESS HOURS OF LIGHT
In the rush to get buds in the jar sooner, it is always tempting to expose plants to 24hrs of light during the vegetation cycle. The plants may grow larger sooner, but this increases the risks of males developing.
Young plants exposed to an 18-6 day-night photoperiod increases the chance of females. The chance increases further when the day length is reduced to 16 hours. To maximize the possibility, reduce the day period to 14.5 hours of light.
Shorter day length does slow growth during vegetation, but the likelihood of females increases to 70–100%. With expensive primo seeds, it is better to allow an extra week of vegetation to get the best value. Some patience during vegetation is preferred to throwing half the crop away later on.
The other downside of 24hr light exposure during vegetation is poor root development and interrupted gas exchange in the rhizosphere. Root development occurs predominantly at night, and necessary oxygen exchange occurs more efficiently at this time too. Healthy roots mean healthy plants.
USE COOL, BLUE LIGHT
Light that is in the blue spectrum during vegetation promotes female development. Fluorescent lights should be white or blue spectrum for infant plants. Refrain from using the purple/red-tinted fluorescents, which are better for flowering.
Metal halide lamps are ideal for the vegetation phase of cannabis. They are blue biased in their spectrum and imitate summer light effectively, which is the natural vegetation period of cannabis. When the 12-12 switch is made to promote flowering, switch to a high pressure sodium light. These a red biased in their spectrum and imitate the red-shifted light of autumn.
Cannabis plants consume lots of nitrogen during the vegetation phase. Increasing nitrogen (N) slightly and reducing potassium (K) can increase the likelihood of females. A potassium-rich nutrient blend will boost the chances of males during the early development phase.
HIGHER HUMIDITY AND MOISTURE IN AIR AND SOIL
High and stable humidity levels from germination right on through to vegetation increases female development. Similarly, consistent and stable watering routines maintain ideal moisture in the grow medium. Stable moisture exposure in the air and medium promotes females.
Young plants: When plants are young, make sure they maintain a high humidity of at least 70–80% RH. This is easily done with a humidity dome during the infant stage. Make sure the growing medium does not dry out too much. There is a fine line between maintaining a healthy wet-dry cycle and over drying. The stress of a too-dry medium will encourage male development.
Pubescent plants: Maintain humidity at 70% RH. Use a hygrometer religiously to ensure ideal moisture content of the growing medium. Maintaining correct humidity is made easier with a humidifier/dehumidifier unit always at work in the grow space. Continue to monitor the moisture content of the grow medium. Overwatering and over drying are stress vectors that can encourage males.
Flowering: Decrease humidity slowly to 40–50% during the flowering phase. Refrain from dropping to this level in one go. Gradual humidity reduction will prevent stress. Too high humidity can cause numerous problems for cannabis flowers. By now, the sex of the plant has been established from the specialized treatment during the vegetation phase.
Following these easy-to-maintain tips can maximize female plant development. Stress of any kind is the enemy of marijuana. It is thought that male development increases the likelihood of pollination during times of stress. A single, well-pollinated female can produce hundreds of seeds, perpetuating the species into the next season.
Indoors, the grower has complete control over the growing environment. This means that any stresses can be minimized with vigilant plant care. Well-maintained young plants increase the likelihood of female plants, which means more buds in the jar at the end of the day.
Preserving Cannabis Genetics: How to Collect and Store Seeds and Pollen
Sometimes a grower has to move on from a certain strain. Maybe you’ve been growing the same strain for a long time and it no longer makes as much money as it used to, or maybe you just want to mix it up and start growing something else and don’t have the space for it.
It can be bittersweet saying goodbye to old genetics, but sometimes it’s unavoidable. You can take clones or keep a mother plant, but those aren’t ideal because they require a lot of care and maintenance, especially if they aren’t producing flower.
Fortunately, preserving genetics for long-term storage is easy and will save time, money, and space in the long run. Through seed and pollen collection, you can hang onto those genetics that you can’t fully get rid of and safely store them for future use.
The Benefits of Long-Term Storage
Cannabis genetics are often sourced from external companies and organizations such as nurseries and seed banks. For the individual grower, saving seeds and pollen removes this reliance on external companies. This is especially true with pollen, as very few (if any) companies offer pollen to the public.
Saving space is a big reason to consider long-term storage of seeds and pollen. Mother plants lay dormant in a vegetative state and take up lots of space. Maintaining this extra space is time-consuming and takes extra resources like water, soil, nutrients, light, and other costly elements, all for something that doesn’t produce flower. Even keeping clones of an old strain around will take up space and resources.
A grower or breeder can also freeze the progress of a breeding project for months or years without losing any of the long, hard work. Endeavors such as phenotype hunting and maintaining desired mothers for breeding and cloning can all be saved for later through genetic preservation. This process is like backing up work on a hard drive.
How to Collect Seeds
Cannabis is for the most part dioecious, meaning that the male and female reproductive organs exist on two separate plants (although hermaphroditic plants do occur). It is also a wind-pollinated plant, so pollen must be transferred from a male stamen to a female pistil via the air in order for pollination to occur and seeds to form.
A female cannabis plant that has received pollen from a male will produce many seeds over the course of its maturation cycle. Upon senescence, when the female plant is fully mature and ready for harvest, its seeds will be ready for stratification and collection.
To collect seeds, it’s important to wait until they are fully mature and ready for harvest. Cannabis with seeds takes longer to mature than cannabis that only produces flower.
To tell if a seed is mature, take a look at its shape and color. Premature seeds will be small and light in color, taking on a beige hue. Fully mature cannabis seeds are more full in shape and size and have a much darker brown hue, sometimes accented by black tiger stripes.
Deseeding cannabis can be done by hand or machine. This process typically takes place after the plant has been dried for one to two weeks after harvest. This way, seeds will have reached their maximum maturity and plant material will be brittle enough to break apart with minimal effort.
When collecting seed by hand, use a fine screen to help catch trichomes that will break off during the process. This material is valuable and it would be a shame to waste.
To release the seeds, simply break up the dried buds over a screen and they will fall out. You can release the seeds en masse by rubbing the flower between your fingers and lightly breaking it apart.
Separate or sift seeds over the screen to remove any unwanted plant matter from the seeds themselves. Brush off the seeds—they should be completely free of any remaining plant material such as leaves, stem, or trichomes, as these elements put seeds at a higher risk for contamination and spoilage during long-term storage.
Male cannabis plants will produce pollen several weeks into their flowering cycle. Once their pollen sacs have opened up and released, the plant will begin to senesce and eventually die. It is important to collect pollen right as the sacs are beginning to open up, as this is the time pollen is most viable.
The best way to harvest pollen for storage is to remove an entire male flower cluster and place it in a sealed storage container for several days. After the cluster has dried, place it over a micron screen with parchment or wax paper underneath, and give it a light shake. This will allow the pollen to separate from any remaining plant matter and fall through the screen and onto the wax paper.
Moisture is a death sentence for pollen viability. Because of this, many breeders opt to mix flour into their pollen at a ratio of 4:1 (flour to pollen) when storing it long-term. This additional step will help keep pollen dry for a longer period of time.
Seed and Pollen Storage
Long-term storage requirements for seeds and pollen are similar. Both require cool, dark, dry, and oxygen-deprived environments for optimal preservation.
When storing seeds, place them in an air-sealed container that doesn’t have any light leaks. Film canisters, medicine bottles (non-translucent), and any sealable storage jar will work fine. The idea is to reduce the amount of oxygen present in the storage space as much as possible. You can also add uncooked rice to the storage container, which acts as an absorbent, to reduce moisture content.
For a cool environment, store seeds in either the refrigerator or freezer. Seeds need a consistent temperature without fluctuation to remain dormant long-term.
As mentioned above, the best way to reduce moisture in pollen is to mix it with flour. For long-term storage, it can be kept in a sealed vial or freezer bag. You can keep it in the refrigerator or freezer, though for optimal long-term storage, the colder the better.
The Shelf Life of Seeds and Pollen
You can expect cannabis seeds that have been sealed and properly stored to last for several years, and in many cases, longer. Seeds may be dormant, but they are still alive. Over enough time, they will lose their viability.
It’s important to continually practice germination testing to be sure your stored seeds haven’t lost all viability. To test this, periodically plant a seed and document its ability to germinate.
Fresh seeds should have a germination rate close to a 100%, whereas older seeds will see a significant drop off over time in their ability to germinate.
Out in the open, pollen may be viable for one or two weeks under normal conditions. However, when frozen and sealed, it can last up to a year and even longer. Pollen is more unstable than seed and even under the most optimal conditions, it isn’t expected to have as long of a shelf life.
For both seeds and pollen that have been frozen long-term, it’s important to avoid defrosting until they are ready to be used. Fluctuations in temperature and moisture content will quickly destroy their viability, so maintain a steady temperature for as long as possible. Warming and freezing multiple times isn’t good.
When it comes time to use frozen seeds, remove them from their container and let them sit out on a dry surface for several hours. Letting the seeds reach room temperature will help ensure a successful germination.
Pollen should also be placed at room temperature before using. Since pollen can be much messier to handle, it’s best to carefully transfer a sample from its long-term storage container to a fresh container before using it to pollinate a plant. This way, you don’t have to use all of the pollen and saved pollen can go back in the freezer with minimal exposure to warm air.