Seed-saving: Collecting Dry Seed

by Chris McLaughlin

It’s easy to save seeds from plants that produce pods, husks, and other dry casings such as peas, beans, and flowers. The technique is called “dry processing” and is faster than collecting seed from fleshy, pulpy fruits such as tomatoes and cucumbers.  Seeds that are dry-processed can be allowed to dry right on the plants unless there’s wet weather in the forecast.

Gardeners collect these seeds in different ways. Seeds often fall where they may, naturally, little by little. Some gardeners make collecting them easy and as the seeds begin to mature, they secure paper bags over the seed heads and attach them to the stems of the plants. Thus, catching any seeds that ripen early.

Once you have the seed, you’re actually left with a mixture of seeds and what’s called “chaff” as opposed to pure seed. Chaff is pod or husk coverings and other debris that fall in with the seeds.

Separating the seeds from the chaff is a technique called “threshing.” Threshing is used to remove the coverings from the seeds. Commercial threshing is done by multitasking machines that can harvest, thresh, and winnow the seeds all at once. For the home gardener, a bag, pillowcase, or small sack is all that’s necessary.

Simply put the collected seeds into the bag, secure the ends, and roll it around, lightly crushing the contents a bit. Don’t get all macho on me and break out a hammer for this — you don’t want to damage the seeds. For the tinier ones, there’s nothing wrong with using a flat board to gently press on the seeds to loosen the chaff.
The next step of dry harvesting is called “winnowing.” Winnowing is just a five-dollar word for getting the loosened chaff off of your seeds before you store them. In nature, this would be taken care of by the wind, but you can use the same idea by placing the seeds into a bowl and shaking the bowl around a bit. Most of the chaff is lighter than the seeds and it’ll rise to the top.

Be sure to have a large sheet underneath your workspace so if any seeds are blown away with the debris, you can retrieve them. Work outdoors only on a day without wind. Now, blow gently into the seeds to remove the lighter-weight chaff. Repeat this process until all (or most) of the chaff is gone.

Be sure all wayward seeds are removed from the sheet underneath before you do any winnowing with other varieties. Another option is to use a screen or sifter where the holes are smaller than the chaff to simply sift them apart. The size of the sifter holes will depend on the size of the seeds and the chaff.

Label the seeds with their name and the date they were collected immediately after you’ve finished dry harvesting each variety. Excellent record-keeping is your best friend when it comes to seed-saving. It’s amazing how easy it is to mix up seed varieties!

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