Most people buy their vegetable seed fresh every year, going to the grocery
or hardware store and picking out pretty packets off of the seed rack. I
hope to explain why this isn't a good idea. Maybe I'll even save you some
Note that, although I focus on vegetable seed, most of the principles involved apply equally to flower seed.
Does It Matter Where I Get My Seeds?
In short, YES.
Seeds are living things. They are conducting metabolic processes, although it is at a very low level. The lifetime of any given seed will vary with both its innate vitality (some plant seeds live longer than others) and its environment. Generally speaking, seeds that have been kept cool and dry will live longer (and therefore have higher viability) than seeds that have been kept warm and wet.
Quality seed companies have special seed warehouses, which are kept around 50F and 50% relative humidity, for this reason. It is important to note that many companies do NOT go to this expense, so it is worthwhile to double-check.
Seed packets, sitting in a grocery/hardware store's seed rack, have probably been at rather high temperatures at times, and almost definitely at high humidity. For long-lived seeds like broccoli, radish, and carrot, this doesn't matter so much if you buy your seed fresh every year. Shorter-lived seeds like spinach and parsnip can be dead by the time you get them home. You might notice that seed racks in general do not carry true spinach; instead they sell either New Zealand "spinach" or Malabar "spinach" (both poor substitutes for the real thing, in my opinion). The reason is, spinach seed is both short lived and not very vigorous, so storage conditions affect it greatly. Spinach seed, left in a packet in a humid grocery store, maybe getting hit with the sun for half a day, would probably be dead after a few months.
How Long Will Seeds Last?
If you keep your seed dry and as cool as possible, you can use the same seed (in most cases) for several years. Just put them in an airtight container in your refrigerator or under your house. Putting silica gel packets or powdered milk (maybe even dry rice) in with them will keep the humidity lower. When you're ready to use them, pull the container out and let it warm up before opening (to minimize condensation on the inside of the container and/or on the seeds themselves).
The following data is from my own experience, supplemented with information from the references at the end of this FAQ.
Long-lived seeds include beets, all brassicas (broccoli, Brussels sprouts, cauliflower, cabbage, collards, kohlrabi), chicory (endive, escarole, radicchio), cucumber, kale, lettuce, melons, mustard, peppers, radish, rutabaga, sunflower, tomato, and turnip. If you keep them cool and dry, these seeds should maintain good viability for five years or more.
Medium-lived seeds are beans, carrot, celery, chard, eggplant, parsley, peas, pumpkin, salsify, scorzonera, and squash. These, properly stored, should last at least three years (in my experience, most of these will still be good at five years of age).
Short-lived seeds generally are not recommended for using for more than one season; however I have used most of these for two years with acceptable germination the second year. This list includes corn, leek, onion, parsnip, and spinach seed.
Can I Save My Own Seed for Next Year?
It used to be that many gardeners would save their own seed for planting the following season. Even commercial vegetable growers did this, often developing locally well-adapted varieties (this was especially true for vegetables which are strongly affected by climate, such as Brussels sprouts).
With fewer people growing large gardens lately, and the coincidental advent of hybrid vegetable varieties, this practice has decreased markedly. In fact, certain organizations have been founded to counter a perceived lack in genetic diversity brought on by these factors (Seeds of Change, Southern Seed Savers Exchange, and Abundant Life Seed Foundation are well-known groups).
Seed saved from open-pollinated vegetables can be expected to produce offspring similar to the parent plants, assuming that only similar plants are allowed to contribute pollen and make seed. Open-pollinated varieties (OPs) are bred by allowing a large number of plants to freely cross for several generations; any plants that do not conform to the desired traits are culled before they can contribute to the subsequent generation (this process is known as rogueing).
Hybrid seed, specifically F-1 hybrids, are produced by crossing two open-pollinated varieties. The parent types are generally highly inbred, so they will express their genetic traits uniformly. Because of this, you generally cannot expect satisfactory results saving seed from hybrids. If you are willing to allow several different hybrids to cross freely, and to work diligently for several generations (rogueing out undersirable plants), you can eventually get a reasonably good open-pollinated variety. The resulting OP will not be as vigorous as the original hybrid, however.
Hybrids tend to be more vigorous than OPs, a well-documented phenomenon
known as hybrid vigor. To explain this in a satisfactory manner is
beyond the scope of this paper (In other words: I can't explain it very
well. If you want to understand why, consult a botany text). A second
benefit to commercial seed growers is the parent lines of a hybrid can
be kept confidential. If they develop a superior OP, competitors can just
buy some of the seed and grow it for themselves. If they develop a good
hybrid, it can't easily be stolen.
References on seed saving and storage
Growing Garden Seeds, by Rob Johnston of Johnny's Selected Seeds. This is a good, inexpensive reference for anyone who wants to know the basics of seed saving and seed storage.
Growing Vegetables West of the Cascades, by Steve Solomon. I think this is the best single reference for a vegetable gardener in the maritime Pacific Northwest. It includes chapters on seed storage, raising transplants, and also a critique of various seed companies from an insider. Steve is the founder of Territorial Seed Company.
Seed To Seed, by Susanne Ashworth. If you are at all interested in saving your own seeds, or just want to know more about how it's done, BUY THIS BOOK. I don't always agree with her philosophically, but this is certainly a first-rate reference book. "More information than you can shake a stick at", as my grandma used to say.
The Cook's Garden seed catalog. "Seeds and Supplies for the New American Kitchen Garden". This catalog lists probable seed life for each vegetable variety, if properly stored. They sell, among other things, reusable silica gel packets.
Territorial Seed Company catalog. "Garden Seed that GROWS West of the Cascades". This catalog lists probable seed life for each vegetable variety, under the conditions most of us store our seed. Territorial will pack your order in a ziplock bag with a silica gel pack for a small fee.
For a good, practical source of information on collecting and germinating seeds, go to Tom Clothier's Seed Page. Tom shares a number of the techniques and insights he's developed and used in his rather large-scale seed-starting operation.
All contents © Travis Saling
This page was last updated November 19, 2013