Long-term storage requirements for seeds and pollen are similar. Both require cool, dark, dry, and oxygen-deprived environments for optimal preservation.
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.
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.
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.
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.
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.
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.
It may seem obvious, without a doubt, but don’t forget to label the different strains you have. Once you store the seeds in their containers you should only open them to plant them. It is not advisable to open and close the container you are using, as the protection your seeds are provided is immediately lost once it is opened, and fluctuations in temperature and humidity can be highly detrimental.
Note these two temperature limits to calibrate the range in which you operate. Keep in mind that the ideal temperature to store seeds is around 6 to 8° C. Hence, the most expert growers have a refrigerator just for this purpose, with low temperatures being constantly maintained. The same is true with regards to humidity: if you do not want your seeds to suffer any damage it is advisable to keep them in places with a relative humidity of around 20-30%.
If you follow these guidelines you can preserve your seeds for several years. In fact, there are experts who contend that, if storage conditions are ideal, there are seeds that will last for up to a decade.
Labelling the different strains, essential to differentiate between them
To keep humidity low, it is ideal to have some sealable containers on hand. To do this, a highly recommended option is to use Eppendorf tubes, a standard piece of laboratory equipment used for the preservation of liquid samples, and the very ones in which we provide our customers with our seeds.
You must not forget that light is another of the factors that directly impact seed germination. Therefore, you must be sure that you prevent light from shining on the seeds that you will later be planting. If exposed to light, they can lose much of their germinative power. This is why at Dinafem we place our Eppendorf tubes in opaque metal boxes, which protect the seeds from light and any possible crushing or breakage during their transportation or handling.
If a container you are using is left open, and a rodent somehow gets into your house, the consequences can be dramatic, both for you and your harvest, of course, because the animal will enjoy a great feast at your expense. This is why, among other things, something as simple as placing your containers up high can be a good way to prevent such disasters.
Whether you choose to store your seeds in a refrigerator designed exclusively for their maintenance, or in a dark corner of your house, you will have to pay attention to other risks that can end up damaging them. Many experienced growers stress that seeds must be dried correctly and left under proper humidity conditions to prevent mould from appearing inside the receptacles. To keep this from occurring, in addition to drying the seeds properly, it is a good idea to always use silica gel when storing them.