Collecting seeds is the holy grail of flower growing techniques. Being able to plant seeds from well-producing plants can increase yield and decrease the amount of money spent on new seeds every season. Seeds can be collected in a few ways: removing by hand from dried flowers or caught by a bag that’s been placed over the head of the flower. The key to successful seed collecting from flowers that lose their seeds by dropping them is knowing when to cover the flowers with a bag.
Collect Seeds For Storage
Once you begin to see changes in the flower post-peak, check back every few days to see if seeds are beginning to mature. At that point, simply place a paper or mesh bag over the flower head and tie it loosely with string. Because the bag materials are porous, the plant will continue to receive enough light and air to finish maturing. The bags contain all seeds as they are released and prevent birds from eating them.
Seeds can be stored for approximately 10-years on average when seeds are dried and left with a less than 8 percent moisture level.
Preparing & Storing Seeds
To achieve this 8 percent moisture level, seeds can be dried in two ways: in a conventional oven or outside. Seeds can be dried faster when placed in a conventional oven set at 100 degrees F and left for six hours2. This same temperature can be reached by spreading seeds out on a flat surface in the shade and out of direct sunlight. The downside to the outdoor method is the potential to lose seed by animals such as birds, squirrels, and chipmunks.
Pay attention to the length of time seeds are exposed to warm air while drying. When seeds are stored dried to less than 8 percent moisture, the chance of producing a hard seed is increased2. While not completely detrimental, hard seeds may still germinate when able to absorb water over a more extended period of time. If a seed becomes hard, you can increase the speed of germination by exposing the seeds to a humid atmosphere for 2 weeks prior to planting2.
Once seeds are dried, store them in a moisture-proof container such as a mason jar or sealed cannister and store in the refrigerator or freezer2. For short-term storage, dried seeds can be placed in breathable envelopes or seed packets. It is important to include basic information such as the date of collection and species name of your seeds before they are stored away. Before being stored, dusting seeds with diatomaceous earth hill help prevent insect infestation, kill any insects that may already be present, and extend storage length5.
Be mindful that recalcitrant seeds from plants such as avocado, mango, lychees, and some horticultural trees will not survive drying or freezing7. These seeds are to be harvested and planted as soon as possible.
Determine Seed Viability With Germination Testing
To determine the viability of seeds that have been in storage, a simple test will do. Test seeds by placing them between two moist paper towels which are then placed inside a zip lock bag. Place this bag in a dark place and walk away for recommended days to germinate. When you return, you’ll immediately have an answer. If you tested 10 seeds and 6 of them germinated, the seeds have a 60% chance at viability1. Alternately, any number less than 5 may still be usable but it is recommended to plant at least double the number of seeds needed for the number of plants you need4. Be sure to make note of the viability rate and the test date on the storage container before being returned to storage.