Saving Seeds For Beginners

Storing Seeds so You Don't Lose Them

CR Lawn, 2009

The year before I founded Fedco Seeds I organized a group seed order with WCP, Central Maine's co-operative produce ordering region in the '70s, plus a growers' group from Somerset County. Being mostly inexperienced growers and wanting to support a local business, we chose a fledgling Winthrop seed company to receive our business. Their prices couldn't be beat, but we found they had stored seeds and onion sets in their greenhouse when we arrived to get our order. Unsurprisingly, the sets already had 2-4 inch sprouts. Needless to say, we didn't give them more business in subsequent years.

They couldn't have picked a worse place to store their seed. Never leave seeds in a greenhouse for even a few minutes. Heat and humidity are the great enemies of seed longevity. Of the two, humidity is the worst and a 10% increase for only a short period of time can halve seed shelf-life. In general, the sum of your temperature and relative humidity should be under 100 for good storage, although seed companies and professionals prefer considerably lower than that. That means that if you keep your house at 70°, you need humidity of under 30%, not easy to achieve. Some seed savers put silica gel in their seed jars to absorb moisture.

Many folks order enough seeds of a variety to last two or three years, thinking to save money by buying bigger packets. But unless they make more than a casual commitment to good storage, that is likely to prove a false economy. I found that unless I took precautions, most seeds were good only for the year I bought them or for one year more at the most. Vigor declined, especially for beans, corn and squash, as well as germination for almost all the rest. While tomato, cucumber and squash seed of the pepo species are exceptions and often last much longer, peas, lettuce, root crops, peppers and most herbs and flowers are finicky. If in doubt about held-over seeds, you can test them for germination by sprouting a few in moist paper towels before trying them outdoors.

A few seeds are not worth storing at all because they have such poor longevity. Parsnips, parsley, anything in the allium family, scorzonera, shiso and some other herbs, larkspur and delphiniums are notorious for short shelf-life and need to be renewed each year.

Probably the best place to keep seeds, provided they are sufficiently dry when you put them in, is in a jar in the freezer or refrigerator. Remember when you take them out to leave them in the jar for a while to allow for the condensation that will occur in their warmer environment. If a fridge or freezer is unavailable, try to find a cool dry place that is out of the sunlight. Remember that mice can climb and gnaw and will consider your seeds, especially cucumbers, melons and squashes, to be yummy food.

What are the best seeds for a beginner to start saving?

Open-Pollinated and F-1 hybrid. Self-pollinating and cross-pollinating. Wet seed and dry seed. Annuals and biennials. If you want to save seeds, it helps to think about the separate categories that make up the alphabet of the seed saver.

At least to begin, you'll want open-pollinated varieties (op for short) because these will come true from one generation to the next. If you save their seed, you will get the same variety next year, provided that you do not allow other varieties to cross with them. F-1 (meaning first filial generation) hybrid seeds will not come true the following year. Because these varieties were the product of a cross of two or more different varieties, in the next generation the different traits that comprise these varieties will segregate out, creating a mishmash of possible combinations. It will take at least 5-7 years of selection and breeding to get back to anything close to the original varieties.

Self-pollinating varieties are easier for the beginner to work with than cross-pollinating varieties. That's because self-pollinating varieties don't readily cross with other varieties of the same species. So you can grow more than one pea, bean, lettuce or tomato variety not far from one another because they are unlikely to cross. But they do occasionally cross, so I recommend a distance of 20 feet or more between different varieties to keep the seeds true. Cross pollinating varieties such as squash, cucumbers, melons, mustards and radish cross readily. For absolute purity you will need to keep at least a half mile between varieties. Several hundred feet should be sufficient if you can tolerate a small amount of crossing. This distance is known as the isolation distance. Other means are available of ensuring purity if you cannot maintain isolations, but they are more labor-intensive and require more skills. Consult a book on seed saving for additional information on them.

Dry-seeded crops generally set their seeds in pods. Often, as with peas and beans the part we eat is the immature seed (and sometimes its pod as well). As the pods dry, these seeds mature. When the pods are dry and brittle, the seeds are ready to harvest. Once you can no longer dent the seeds with your thumb-nail, they are dry enough to store. Beans are the easiest seeds for beginners because they are large and dry-seeded and can be easily shelled. Also they are distinctive and beautiful with their patterns and colors, and it is easy to tell when the varieties get crossed because their colors and markings change. Peas are also easy, but prone to disease in our moist climate. Often saved pea seed is better than commercial seed of the same variety because peas adapt quickly to their growing conditions, but do not save seed if you have any diseases such as powdery mildew or fusarium in your patch, or you risk transmitting disease into the next generation. Lettuce seeds are also dry self-pollinators, but unlike peas and beans, require patience to clean from the chaff.

Wet seeded crops are those found in moist cavities such as cucumbers, squash and melons, or surrounded by gel sacs inside wet fruit like tomatoes. These should generally undergo a fermentation process. Squeeze them into a dish with their surrounding moisture, add water and allow to ferment for several days. They will get moldy and smelly and then you can decant the moldy stuff and draw off the seed. The fermentation helps kill off seed-borne diseases. Of these, tomatoes are probably the easiest. You can get a remarkably large quantity of seed from a relatively small effort from these crops. And you can get to have your cake and eat it, too as you can save the seed and still enjoy the fruits.

Annuals set seeds the first year and, as a result, are the easiest. Some, such as lettuce or mustards, grow taller and take longer than we are accustomed to when we arrest their growth to eat them as food crops. Lettuce must be started indoors in our climate to set seed reliably in time. Biennials set seed the 2nd year. Except for parsnips, in our climate, we must harvest biennials in the fall, bring them inside and re-set them in the spring. They don't set seed till the second year. Carrots, leeks, onions and parsnips are in this category. Parsnips are the easiest, because they will over-winter in Maine without necessitating removal, and grow huge and set copious seed in year two. Also, homegrown parsnip seed germinates better and has more vigor than any you can buy.

Good luck with your seed saving adventures!