As summer begins rolling into autumn, it’s time to get busy saving seeds from your summer harvest.
First, remember that HEAT and MOISTURE are the enemies to seed viability after storage. In other words, just the things that make a seed germinate when planted are the same things that will kill them during storage and prevent germination later when planted.
Even if the poorly stored seeds germinate, they may produce weak, spindly plants that do not produce fruit or vegetables. You may get carrot sprouts, but never any root bigger than a thread, even after months of growing.
When stored properly, some seeds can last 5-10 years, but this depends on the type of seed. Some seeds don’t do well in the second year, no matter how good the storage conditions are. Seed banks use climate-controlled environments (temp/humidity) to store their seed banks and grow them out every second or third year.
Fedco Seeds has a great chart on Seed Saving for Beginnners, which gives great information including seed longevity. Most seeds store well for 2-3 years, but wide variations exist. For example, onion will only last one year, and leek will last two at the most. Cucumbers, melons, and tomatoes can last up to ten years. I have successfully grown tomato plants from seven-year-old seeds. Remember, though, the younger the seeds, the more vigorous the plants will be.
If you are faced with an emergency where you had to get a garden in and survive off what you produce, you will also need to harvest seed from that garden so you don’t use up all your precious seed bank and have nothing left for the next season. If your emergency is such that you have enough time to grow a garden, you may need to do it for more than just one season before you get any kind of meaningful harvest.
There is no substitute for experience in the garden. I recommend a fantastic book by Steve Solomon called Gardening When it Counts: Growing Food In Hard Times. His premise is that you are gardening because you will live on what you grow, so you cannot afford to waste money or fail. This book was not written specifically for any particular state or zone and is not for the Square Foot Gardening crowd, but it is full of extremely valuable advice gained from decades of experience with subsistence gardening. He also discusses seed longevity and seed saving. I highly recommend the book.
Ideally, you would grow your seeds every year and save seeds from the most vigorous plants and the best fruits. This way, your seeds will always be fresh. Even living in an apartment, you can practice growing seeds on your balcony in pots. That said, you may purchase seeds for your garden and only plant some and save the rest for the next years. I do this, and it’s a great money saver.
When you have seeds to store, they should be stored in an airtight container in a cool, dry place. A mason jar in the refrigerator is ideal. Adding a desiccant, oxy pack, or pumping down to vacuum would also improve shelf life. Do not store seeds in a frost-free freezer without ensuring the container is airtight. Ever seen an ice cube left too long in a frost-free? It evaporates. This will kill your seeds. Seeds need to maintain a low level of moisture to survive. If you buy your seeds in a #10 can, keep it in the refrigerator. Every 10-degree F increase in temperature above standard conditions combined with a 1 percent increase in the seed’s moisture content cuts the seed’s storage life in half.
Last but not least, make sure you purchase good quality seeds to begin with. Some seeds are nearly worn out when you get them. If you purchase seeds that have been stored in an outside nursery with lovely trays of flowers under a mister system, they are in trouble. I was at a “big box” garden center the other day, and the seed envelopes were under the shade cloth outside, in the heat, near the flowers. The packages had been so damp they were bent over. They had probably been out there all summer. I checked the envelopes and the seeds were loose in the packet and not inside a foil pack inside the envelope. At a “supercenter” I went to, the seeds were inside the air-conditioned part of the store and well away from any moisture. These would be a much better bet. The best place to get seeds for storage is through mail order or order online from a reputable dealer. My favorite is Fedco Seeds for quality, price, and customer service. There are several other good ones as well. These seed dealers store their seeds appropriately and test germination each year for each lot.
Guest post by Marta Waddell. Marta is a master gardener for the University of Arizona, a speaker and trainer.