High-quality cannabis seeds have a germination rate of around 80-100% if cultivated within six months. But growers sometimes want to wait longer, perhaps using just some of their latest batch, or collecting the seeds from a successful harvest and saving them for future use. Thankfully, it’s possible to effectively store marijuana seeds until you’re ready for your next crop. But using the right techniques is crucial. Knowing how to store cannabis seeds is fundamental to ensuring their viability.
Why is Proper Storage Important?
There are a variety of environmental factors that can damage seeds or cause them to germinate too early. And understanding these factors is key to determining the best way to store marijuana seeds. Seeds are in a state of hibernation before the germination process. You aim to keep them healthy and prevent this process from starting until you’re ready to begin germination yourself. This requires you to control their environment. Which you can do by ensuring correct storage methods.
How Long Can You Store Cannabis Seeds For?
Cannabis is a hardy plant. Marijuana seeds can maintain good levels of viability for up to five years if stored correctly, and plants have even been grown from seeds over a decade old. But it’s important to remember that the chances of successful growth decrease over time, falling markedly after that five-year mark. And they’ll only remain viable that long if stored properly.
Key Environmental Factors
If you want to preserve marijuana seeds until ready for use, you must store them in the right conditions. The key factors for storage are; moisture and humidity levels, temperature, light exposure, and access to oxygen:
Moisture and Humidity
Marijuana seeds are naturally dry, requiring moisture to open, start developing roots, and begin germination. They’re also very effective at absorbing moisture when placed in wet atmospheres. As such, you must keep them dry to prevent premature germination.
Even at levels too low to induce germination, moisture and humidity are deadly. Moisture levels of 12-14% create a perfect breeding ground for fungi, while levels of just 8-9% attract insects and other pests. The respiration of fungi and bacteria also increases the temperature of your storage environment, further reducing the chances of your seeds germinating.
Like moisture levels, higher temperatures can induce germination. In nature, an increase in temperature often signals the start of the growth phase, and your seeds will respond accordingly when exposed to heat. At excessively high temperatures, they may even rot.
Therefore it’s recommended you store marijuana seeds below 5ºC. At this temperature, they will not begin to germinate, and the chances of pests becoming an issue disappear. Avoiding temperature fluctuations is also vital. Establish conditions below 5ºC and maintain them for the entirety of the storage period.
Again, light drives germination. It won’t initiate germination on its own, but sun exposure can partially awaken dormant seeds, sparking chemical reactions that will hinder their ability to germinate later on. Exposure to UV radiation also breaks down chemical chains within seeds. Marijuana seeds subjected to this internal sunburn will produce unhealthy plants with poor yields if they are even able to germinate.
Oxygen levels are another aspect to control when trying to prevent germination. Seeds need oxygen to germinate, so it’s imperative you cut off their supply. Bacteria and parasites also need oxygen. An airtight storage method will inhibit seed respiration and has the bonus of keeping pests at bay.
The Best Way to Store Cannabis Seeds
To preserve your seeds, they need to be stored in the right environment. And achieving those optimal conditions requires preparation, the correct storage container, and the right location.
Make Sure Your Seeds Are Dry
Dry your seeds before storing them. Though we want to eliminate moisture, an environment with a 0% moisture content can also kill seeds. The ideal moisture level is 2-3%, which can be achieved by storing a desiccant inside the container with your seeds. Silica gel packs are especially effective.
You can test that your seeds are sufficiently dry by leaving them in a container at room temperature for a few hours before storing them. If condensation forms inside the container, further drying is required.
Choose the Right Container
A light-proof, airtight container is essential. Film canisters are ideal for short-term storage and will keep your seeds protected for several months. If storing your seeds for longer, it’s recommended you vacuum-seal them. Don’t cut corners with this step. Water molecules can pass through the pores of most plastic containers, and zip-lock bags aren’t sufficiently airtight.
Glass jars with glass lids and airtight closures are also suitable for both short and long-term storage. But avoid containers where the lid and body are made from different materials. Different materials expand and contract at different rates, creating minute gaps that will compromise the environment inside your container.
Where to Store Your Seeds
Once packed, you should store your container somewhere cool, dark, and dry, and where conditions will remain constant. Growers often disagree on the best place to store seeds but typically choose one of three options:
A dark cupboard in a cool location should be sufficient to preserve your seeds for up to three years. But remember, you must maintain stable conditions. If you cannot regulate the temperature of your cupboard, or if you’re likely to disturb the darkness by regularly opening the door, it’s not the right place for your seeds.
Refrigerators are great for storing marijuana seeds. They’re cool, dark, and offer precise temperature controls. It’s recommended you keep them near the back of your fridge, where light exposure and minor temperature fluctuations resulting from day-to-day use are minimal. Moisture levels in fridges can fluctuate, so a container that adequately protects your seeds is essential. Do it right and the fridge is perfect for both short and long-term storage.
When it’s time to use the seeds, allow the container time to sit at room temperature before opening it. This will cause condensation to develop on the outside of the container instead of the seeds.
Freezing seeds is a popular long-term storage method, but not advisable. Seeds undergo cellular expansion when frozen, with the merest hints of moisture causing cells to rupture. Specialized laboratory equipment can progressively lower seeds to sub-zero temperatures without causing this damage, but the process cannot be replicated with standard household equipment. This cell damage makes seeds non-viable, and most growers will damage at least some of their stock by storing it in the freezer.
Additional Tips For Marijuana Seed Storage
Label Your Containers
Label your container with the strain and quantity of the seeds stored. And the date. It’s easy to forget these important details later.
Check Your Seeds Before Storing
Assess your seeds for cracks and other damage before storing them. These kinds of blemishes drastically reduce their longevity. Seeds with surface damage should be planted immediately to maximize their chances of growing successfully.
Quality Makes A Difference
High-quality cannabis seeds generally remain viable for longer than low-quality ones. Other variables, like the hardiness of a strain, are also a factor, but storing seeds is no different from planting them: for best results, seek the best quality seeds.
So now you know how to store cannabis seeds. Ultimately, it comes down to controlling the environment. By regulating moisture content, temperature, light exposure, and oxygen levels, creating the optimal conditions to store marijuana seeds is easy. Follow these few simple steps and you can preserve your seeds for years.