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How to tell when cannabis seeds are ready to harvest

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.

Collecting Pollen

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.

When to Harvest Cannabis Plants

Cannabis growers spend a lot of time taking care of their plants in order to produce much better results. Sometimes it can be hard to wait until the time is right to harvest; between impatience and that feeling of being near harvest time, it can be hard to resist. Knowing when to harvest cannabis is quite subjective; growers all have their own method, plus it depends on the substrate, water quality and other determining factors.

This post is designed to help growers that have just started out and have questions regarding when to remove the flowers from their plants in order to cure and dry them. We’re going to have a look at some of the most important things to keep in mind when harvesting cannabis and knowing what a mature plant looks like.

How to Tell if your Plant is Ready to Harvest

There are plenty of signs that can show you when to harvest your cannabis plants. There are also lots of myths and legends that end up causing growers to harvest too early or late. Some people even think harvesting early will stop them from going bad – most growers have had that thought at least once, but if you let them keep growing without getting too impatient, you can get some amazing results. There are still many things you can keep in mind when figuring out when to harvest cannabis. For best results, use a good pair of pruning shears.

Seed Bank Reference

Whenever you get your cannabis seeds, we highly recommend checking out the dates given by the seed bank and their recommendation. They know their strain perfectly and they’ll be able to guide growers with the correct information. Keep in mind that these dates are still just guides, and aren’t 100% accurate. There are many different factors that intervene when it comes to each plant (growing conditions, outdoors or indoors, level of care, latitude etc.). Nirvana Seeds, Seedsman Seeds, Barney’s Farm, Ministry of Cannabis, Exotic Seeds and GB Strains all have an amazing selection of cannabis strains.

Pistil Color

We all know that the pistils are the little brown “hairs” on your cannabis flowers when they begin to mature. These pistils can, in some cases, be a sign that your plants are almost entirely ready to harvest. The less brown, the more psychoactive and the more brown pistils the more intense the narcotic effect. Some growers recommend harvesting when more or less half of the pistils are brown, while also keeping in mind the effect/flavor/aroma that you’re looking to get.

Keep in mind that pistils going brown doesn’t almost indicate that your plants are ready to harvest; it could be caused by excess watering, spraying at night, having used a certain type of spray product, stress etc. Once your cannabis plant is ready to harvest it won’t be thirsty anymore, absorbing much less water than usual.

Trichome Shape

Trichomes are small cells that appear on the surface of your plants’ leaves and flowers. They contain cannabinoids, which produce psychoactive and narcotic effects in your buds. They look like droplets, and keep growing until they take on a mushroom shape. A good sign is that they’re no longer producing any more trichomes. Essentially, you should see calyxes covered in resin, which essentially look like mushrooms when looked at under a microscope, and they’ll want to have a creamy, milky color and some should be an Ambar-like color. The best way to check if your plants are ready is to use a Mini 60x Microscope With White LEDS.

When the top of the trichome is perfectly round, it’s too early to harvest. You’ll need to wait until they look like a sort of an over-pumped ball, slightly deformed. This indicates that there are more cannabinoids inside. If you don’t harvest early, they’ll explode and degrade – if you wait until they explode, you’ll have waited too long.

What Happens When you Harvest Cannabis at The Wrong Time

All of the previous signs can help you to figure out when your cannabis plants are ready to harvest. However, it’s pretty easy to get impatient towards the end – you’re itching to taste your buds and see how the effect hits. However, this usually leads to issues with your harvest.

If you harvest too early, you may run into quality issues with your harvest; the flavor will most likely be less intense, its buds will produce less chlorophyll and therefore less terpenes. Plus, their buds will probably be a lot smaller and less dense than what you were expecting. Keep in mind that it can also influence the effect, as the pistils haven’t finished growing yet – you can lose a large part of your harvest if you don’t wait long enough.

If you wait too long to harvest, it’ll will essentially go “bad”. The flavor will be much softer and it’ll take less time to cure. The more time goes by the less psychoactive the effect is. This is because THC turns into CBN when it begins to degrade, losing most of its characteristic effects. If you wait longer, your cannabis will have a more relaxing, intensely narcotic effect.

Recommendations for When to Harvest Cannabis

We highly recommend following the previous advice as much as you can; if you don’t have the tools to fully check on your plants, don’t just go by the amount of brown pistils on your plant, pay closer attention to the state of the leaves and how they begin to use up their reserves and fall off. The best way to tell when to harvest is by using a microscope; if you don’t have one, wait until its pistils are more or less all brown and then wait another week or two. If the seed bank says 60 days, you’re better off stretching it to 75 days.

When done right, you can harvest enormous flowers. These tips and tricks can help you to harvest delicious, large and high quality yields. We hope this information has been useful, and that this year you have a better idea regarding when to harvest cannabis plants! If you have any questions or suggestions, go ahead and leave a comment below.

When To Harvest Marijuana Seeds?

After the whole process of germination, growth and flowering, a lot of growers ask themselves when to harvest Marijuana seeds. Usually, the breeders will include a suggested flowering time for each strain, but as a rule of thumb, Indica marijuana plants harvest in 6-8 weeks while Sativa Marijuana plants take 10-12 weeks.

Look for these signs for when to harvest Marijuana seeds

You can also judge the ripeness of the Marijuana by taking a look at the trichomes; or little hairs/crystals on the flowers and surrounding areas of the Marijuana plant. If they are transparent its still too soon, if they are milky white they are ready and if they turn brown they have become over-ripe. It is also advisable to follow the instructions to harvest Marijuana seeds on the packet since most reputable breeders also have a tried and tested flowering time for optimum ripeness, potency and flavour of a Marijuana strain.

If you meant when to harvest seeds from cross-pollinated Marijuana plants, then the seed will fall from the flower by itself once it is mature and ready to germinate into another Marijuana plant. Usually, as a best practice to harvest Marijuana seeds, some growers wait for the whole flowering cycle to end just as if they were harvesting the flower.

You might find our FAQ Submission How Do I Harvest My Plant? useful