Seed Saving Time: Harvesting Dry Seeds

Freshly harvested lettuce seed ready to be cleaned.By Jill Henderson – Show Me Oz

For gardeners, the most rewarding part of the season is when the harvest begins and all those luscious fruits and veggies really start to add up.  For seed savers, that joy is doubled when, in a few short weeks after the fresh harvest begins, the handful of fruits or plants that are purposely left on the vine to mature begin to set seed.  After a long season of planning, cultivating, monitoring and harvesting the bounty of the garden, the reward is more than bountiful!

Are Your Seeds Ripe?

The first thing a seed saver needs to know is when the seeds they are saving are really, truly ripe.  Usually, it’s not when the fruit is ready to eat.  You see, almost all of the vegetables that we eat are immature versions of the ripe fruit.

Cucumbers are massive fruits by the time their seeds are really ripe.

Cucumbers, okra, lettuce, radishes and peas are all picked for consumption before the fruits have the chance to ripen the seeds within.  Some, like biennial brassicas, need two full years of growth before they will produce seed at all.

Certain plants, such as tomatoes, melons, and beans, produce copious numbers of fruits, allowing the gardener to consume a portion and still have plenty left to produce seed.

However, produce from other crops like broccoli, radishes, turnips and head lettuce must be left completely intact if seed is desired. Very few of the vegetables we eat remain on the plant long enough to produce viable seed and those that do are often quite unappealing as food. For example, cucumbers are enormous, yellow and very soft when ripe.

Harvesting Dry Seed

Dry seeds are those which are produced in pods or on flowering stems.  These include all of the brassicas (cabbage, kale, broccoli, kohlrabi, collards, etc.), head and leaf lettuces, all root crops and all legumes.

The seeds produced on flowering stems are ripe when they begin to turn from green to brown/black, or when the fruit capsules or pods begin to open. These seeds should be gathered before the plant disperses the seeds naturally through a process known as “shattering”.

The lettuce seed is almost ready for harvest.

Allowing the plant to shatter is great if you want a self-sowing edible like lettuce or spinach, otherwise you’ll want to gather entire stems or clusters just as the seeds ripen, or by shaking the ripe seeds out of their pods and into a waiting bucket or paper bag.

You can also pull out entire plants, cut off the root at the main stem and stuff the seed heads into a paper bag, feed sack or drop cloth and hang it from a rafter in the barn or an airy shed until completely dry.  Any container or contrivance that will hold your harvest and allow good air circulation can be used.

For legumes, the seeds are ripe when they can be heard rattling inside the pods. Because these types of seeds are already hard and almost fully dry when mature, cleaning them is as simple as removing the seeds, winnowing the chaff and storing.

No More Chaff

Seed screens are extremely useful when processing large amounts of dry seed, especially when the final appearance is important.

Seed screens are deviously simple.  A wooden or metal frame is securely fitted with a flat metal screen. Screens vary in mesh size, allowing different sized seed to be sifted through the holes.

Seed screens are used to seperate seeds from chaff. Image copyright Jill Henderson

Seeds and chaff are placed on the top of the screen and sifted or pushed through the holes. In most cases the openings in the screen are used to allow the seeds to fall on to a waiting tarp or other vessel, while the chaff remains on top, but sometimes it is the chaff that is sifted out and the seeds kept on top.

Another way to clean dry seeds is known as threshing.  The ripe and dried pods or seed heads are placed in a sack or wrapped in a tarp and flailed or otherwise crushed to release the seeds.  It can be as physical as beating the material with a blunt object or stomping or crushing them with a hammer, or as gentle as rubbing seed heads between gloved hands.

Winnowing lettuce seed. Image copyright Jill Henderson

Once the seeds are free, the entire lot is winnowed in order to separate heavier seeds from lighter chaff.  In this process, the relatively heavy seeds fall straight down while the lighter chaff and immature seeds blow away.

This is often accomplished by pouring material that has been threshed from one vessel to another, allowing the contents to fall freely through lightly moving air.

Other winnowing methods include tossing the contents into the air from a basket and catching the falling seeds (fun, but a bit tricky at first), by sifting the chaff through various sized screens, or by using a batten and tarp or board that has been set on a slight incline and allowing the heavier seeds to roll down to the bottom while the chaff is held back by the batten. For home gardeners and seed savers, removing all of the chaff is not necessary to the function or preservation of the seed itself.

Storage Safety

Seeds are living, breathing, life forms capable of remaining dormant for long periods of time, germinating only when environmental conditions are just right for the growth of the plant they will soon become.  But even the best kept seeds don’t last forever.

Clean lettuce seed.

If you save your own flower, vegetable or herb seeds, you can help increase their lifespan by following just a few simple steps.  To learn more about the right way to dry and store your seeds and how long you can expect them to live, check out my article Seed Saving Time: Drying and Storing Your Home Grown Seeds.

Happy Seed Saving!

© 2015 Jill Henderson  Feel free to share with a link back to the original article.

The Garden Seed Saving Guide by Jill HendersonThe Garden Seed Saving Guide
Seed Saving for Everyone!

Save money, become more self-sufficient and avoid GMO’s by saving seeds!  This excellent resource for beginning and hobby seed savers takes you step-by-step through every aspect of saving your own seed in plain English.

Available in the Show Me Oz Bookstore
Look inside!

Jill Henderson is an artist, author, and the editor of Show Me Oz . Her books, The Healing Power of Kitchen Herbs, The Garden Seed Saving Guide and A Journey of Seasons can be found in the Show Me Oz Bookstore.  Jill is a contributing author for Acres USA and Llewellyn’s Herbal Almanac and her work has appeared in The Permaculture Activist and The Essential Herbal.

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3 responses to “Seed Saving Time: Harvesting Dry Seeds

  1. Great post! A lot of good information:-) I will pass this on to those that ask me for more information on seed saving!

  2. Pingback: Seed Saving Time: Harvesting Dry Seeds | Share the Seed

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