Saving Seeds

Late summer is a great time to save seeds for next year's garden. Many of our favorite annuals, vegetables, and native plants are maturing seed now, and the often pleasant late summer weather is conducive to getting out in the garden and harvesting them. Here are a few tips for seed saving at home:

1. Moisture is the enemy. If you harvest seeds that are too green, or leave too much green plant matter with them, or store them in a location with high humidity, they are likely to mold. Always harvest fully mature seeds. When in doubt, wait a few more days. Harvest after a period of dry weather. Remove as much chaff as possible before storing seeds.

2. Use paper bags, not plastic. Harvest entire seed heads from plants such as dill. Place the seed heads upside down in a paper lunch bag. Fold over the top of the bag, label, and place it in a warm, dark location, such as an interior closet. In a week or two, you can separate and discard most of the chaff easily. This works for cilantro, many varieties of annual flowers, and native plants such as lobelias and milkweeds.

3. Hands came before tools. The most effective tools for breaking small seed capsules, plucking the fluff from milkweed seeds, and similar tasks are your hands. Seeds are often tiny and delicate. Handle them with care.

4. Wet seeds need special attention. Seeds of tomatoes and cucumbers are surrounded by a jelly-like material that must be dealt with to prevent mold damage. One recommendation is to place the seeds and their jelly in a jar of water and let the mixture ferment for a week or so before straining out the seeds. Rinsing the seeds repeatedly in a strainer removes any residual material, and the seeds are then spread out to dry prior to storage. This is a suitable technique for producing seeds in large quantities, but if your needs are limited to a few dozen seeds of any given plant, there is a better way. Simply remove the seeds and their jelly with a spoon and spread the mass out on a paper towel, in such a manner that individual seeds are spaced a short distance apart. Use the back of the spoon to assist in this task. Allow the seeds to dry on the towel for a day or two in a warm, airy spot. You should then be able to pick off individual seeds with a pair of tweezers, or by scratching gently with a fingernail. The jelly material will remain behind, absorbed into the fibers of the towel, producing no mess and no smell. You can simply toss the towel into the compost bin when you have harvested the seeds.

5. Native plants may need a cold period. Many native plants produce seeds that will sprout only after they have been subjected to a period of wet, cold weather, as we normally experience each winter. These seeds should be planted out soon after harvesting. Either plant in containers, or label a spot in an outdoor bed, so you won't forget next spring and dig up your seedlings by mistake.

It is worth noting that the fruits of some native plants may contain chemicals that irritate the skin of sensitive people, much like poison ivy. For example, the fruit cluster in the image is green dragon, Arisaema draconitum. The juice from the red berries is an irritant. For safety's sake, wear disposable gloves when working with any plant material, until you are sure you won't experience any consequences. This type of fruit, by the way, is a good candidate for the "let it rot" approach noted above. Along the same lines, beware when removing the relatively dry seeds from hot peppers, as the juices can burn your eyes and skin.

6. Store seeds dry and cold. Vegetable and flower seeds that you will plant next spring should be stored in an airtight container in the refrigerator. Plastic food storage containers work great and are inexpensive. Place individual seed varieties in small paper envelopes. Save the silica gel packs that often come with electronic equipment. Place several packs in the storage container to keep humidity low. Do not store seeds in the freezer.

The seeds of beans, peas and other legumes are easy to save. Allow the pods to dry thoroughly on the plants and then shell out the seeds.

Remember that it is worthwhile saving seeds only from "open pollinated" vegetable varieties. These are non-hybrid plants that will come true from seed next season. Hybrids typically produce seeds that revert to parental types. Make sure you know the plants from which you are obtaining seeds.

Butterfly and hummingbird flowers typically are among the easiest annual plants to grow from seed. They include milkweeds, salvias, morning glories, and the huge annual aster family, including sunflowers, daisies, cosmos, asters, marigolds, zinnias, and many others. For these plants, you need only purchase seeds the first season, and you should have all you need thereafter. The same caveat applies to hybrid plants in this group as was mentioned for vegetables. However, in the case of flowers, it may not matter if the offspring are a bit different from their parents, as they usually bloom and attract pollinators anyway.