If you plan on growing your own herb, then knowing how to properly store your seeds for future germination is extremely important. Storage isn’t a simple matter of throwing your newly acquired seeds in your bedside drawer. There are some important factors to consider that will ensure your crops will be successful.
We get two different types of seed categories in the plant world. These are:
- Orthodox Seeds
- Recalcitrant Seeds
All you need to know about this is that cannabis has orthodox seeds. This means that unlike recalcitrant seeds, cannabis seeds enter a dormant (sleep) stage and will survive the drying process. We can prepare our seeds for long-term storage without the risk of instability by following certain guidelines.
This guide will be all you need to know and we will cover these main topics:
- Storage Methods
- Storage Containers
These factors are very important and they will help keep seeds viable and ready for germination after both short and long-term storage.
The environmental factors have a big effect on cannabis seeds. These include:
- Oxygen concentration: lowering the oxygen in the immediate environment of your stored seeds will slow down or prevent premature germination by reducing seed respiration.
- Ethylene concentration: After exposure to moisture or water, seeds immediately begin to produce ethylene. This is a naturally occurring plant hormone and can be prevented by keeping moisture to a minimum.
- Temperature: Constant changes in temperature can significantly reduce your seeds life.
- Moisture: By minimizing exposure to moisture you won’t accidently germinate your seeds before you ready to begin growing.
- Light Exposure: Light is needed for plants to grow so by keeping your seeds in the dark you will keep them sleeping until you want to grow.
Drying your seeds slowly and properly is very important before you begin storage. During ripening and drying, the cannabis seeds will prepare for their dormant stage by slowing or stopping most processes. The best moisture percentage is around 3%. This can be most closely achieved by placing a silica gel pack (a desiccant) in the storage container of your seeds. The use of a desiccant when drying your seeds will greatly improve their stability.
Keep your seeds dry, dark and cool with a constant temperature and no fluctuations in environment and this will ensure your stored seeds will germinate.
Many growers have a personal favorite location for the ultimate seed storage spot. Each has their own positives and negatives; here are examples:
- Room Temperature Storage: This method is ok in my opinion. Keeping your seeds in an airtight container (with a desiccant) in your closet or bedside draw for shorter periods of time is ok, but not for long periods.
- Freezer: This is a popular method but despite this, the freezer method actually destroys cells in the seed itself. This method is not recommended but if you going to use the freezer, put the seeds (with a food grade desiccant) in an airtight container and store.
- Refrigerator: Even though the fridge is dark and cool, there is a changing moisture factor every time you open the door. Placing seeds in an airtight container with a desiccant is a good option but be sure to store them at the back where there is the least chance of mold.
If you planning on long term storage and you have purchased seeds that come in a vacuum sealed bag with a desiccant, it may be best to leave them sealed for storage. If you have obtained seeds from a friend or are preparing your own for storage, then you may want to consider investing in a vacuum sealer.
The aim is to store the seeds in an airtight environment. If a vacuum sealer is unavailable to you then be sure to use a container that is airtight. A mason jar or a glass jar with a lid will do best. Most plastic containers are not advised as they don’t seal properly and water can still be absorbed through plastic. Only use plastic containers if you have to and only for short term storage. Ziploc bags are also not recommended as temperatures will fluctuate too much and they are not completely airtight.
Glass containers are the best choice and are most recommended for their optimum storage conditions. These are suited for both short and long-term storage. A glass jar is easy to open and close and is reusable. Glass containers are airtight and give your seeds the best environment for storage.
Desiccants such as silica gel packs are a must inside your seed storage containers. These little moisture-absorbing devices will keep moisture levels at 2-3% inside your storage containers. Not only will they extend your seeds life by absorbing excess moisture but will also absorb ethylene produced during seed aging.
Silica packs are reusable and so they will save you time and money over using things such as rice to absorb moisture instead.
- Labels: If you have several different strains you wish to store then both internal and external labels will be best so you don’t get confused.
- Desiccant: Place the silica pack or other desiccants into your container first and then place a layer of cotton wool on top before placing seeds into the container.
- Seeds: After adding your pre-dried seeds be sure to seal your container tightly.
Place your tightly sealed container in your desired location and wait until you are ready to grow. Cannabis seeds are living and so they should be handled with great care. When cannabis seeds are correctly stored they can be kept for up to 10 years (perhaps longer).
Follow our guide for seed storage and you will be sure to enjoy the fruits of your next harvest.
Written by MCSB Team, May 2018
~ Medical Cannabis Seed Bank