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Science Lesson: How to Save Seeds

These instructions are kindly provided by Alicia and Dave with KC Farm School at Gibbs Road. Thanks to the Farm School for helping us learn to be stewards of our world! The Farm School has a seed library that will take your extra seeds as donations and is open to anyone who need seeds to plant. It is a gift economy.

Seed Library Instructions

KC Farm School Seed Library is for everyone; there is no membership and you do not have to return seeds, although you are welcome to do so. We want you to take seeds home, plant & harvest the benefits of growing your own food & flowers!

Taking Seeds

Find the seed you are planning to grow. If you want only a portion of seed from any envelope, take what you will plant and put your seeds into another small envelope from the top of the catalog and label your new seed envelope, leaving the other envelope in the box where you found it. If you want a whole small envelope, help yourself to what you will grow in the next year. Return any small box you take out to the slot where you found it ( they should be alphabetized). Do this for all the seeds you will be using, filling separate small envelopes for each. Go grow! Share with friends and family.

Sharing Your Seeds

Harvest and preserve your seeds based on your experience and the recommendations you can gather from trusted sources. At 4223 Gibbs Road, Kansas City, KS, 66106, Fill out a Seed Library envelope with the seed type, date collected, and location where it grew (include all the details you know). Write down any known growing Instructions on the seed packet. Put the seed in the Seed Library Envelope and place it in the appropriate box in the Seed Library Catalog.

Thanks to the El Cerrito Community Garden Seed Library for guidance on these instructions.

Saving Seeds

Want to save vegetable seeds to replant next year? Here’s our seed-saving guide for beginners. Learn how to harvest and save seeds from some of your favorite garden vegetables, including beans, peppers, tomatoes, and more! Using seeds from your own plants connects you with the earth’s natural cycles, and many gardeners find this activity rewarding, especially as it helps to preserve heirloom varieties and promotes genetic diversity. (This information was pulled from a variety of sources, and from staff practices over many years)

Which Seeds to Save

Some crops are easier to save than others. If you are a beginner, we would highly recommend that you start with vegetables such as peas, beans, lettuce, and tomatoes. Also, here are a few guidelines:

First things first. Only save seeds from “open-pollinated” varieties, as this ensures that the seeds produced this year will result in the same plants next year. Also, remember that some crops can cross-pollinate if they are planted too near each other. For saving seeds, it’s best that the variety of seeds you are saving isn’t intermixed with other varieties.

It’s important to know when a seed is fully mature. It is NOT always when you would harvest the seeds for eating.

Tomatoes and Cucumbers

Because tomatoes and cucumbers have seeds that are coated with a gel, the first step is to remove it by fermentation. The process smells bad, however, so don’t do it in an enclosed room in the house. Tomato seeds may last for more than five years. Follow these steps:

Squeeze or spoon the seed mass into a waterproof container (glass, jar, plastic cup, or deli container).

Add enough water to equal the volume of the seed mass, and put the container in a warm spot out of direct sunlight. Stir the contents at least once a day.

In a couple of days, the viable seeds will sink to the bottom and bad seeds and debris and white mold will float to the surface. Wait five days for all the good seeds to drop, then rinse away the gunk at the top. Wash the seeds in several changes of water, and lay them out in a single layer on a glass or plastic plate or screen. Put the plate in a warm place until the seeds are fully dry, which can take several weeks.


Cut peppers open to find the seeds in a mass on the central stem. Brush them off the stem onto a plate or screen. Put seeds aside to dry.

Squashes and Pumpkins

When squashes are ready, break them open and remove the seeds. Hold the seeds under running water, rubbing them between your fingers to remove any stringy material and membrane.

Then lay them out on a plate or screen to dry.

Peas and Beans

Pick the brown pods from the vines and remove the seeds, which will require about six weeks of air-drying. One way is to put them in loosely woven baskets and stir them once a day. If frost or other inclement weather threatens legumes that are ripe but not dry, pull up the vines by the roots, and hang the plants upside down in a warm area, such as your basement or barn. The pods will draw energy from the plants for another few days, which will increase the seed viability.


For watermelons, simply rinse the seeds under running water to remove any traces of flesh or membrane. For cantaloupe and musk melon, seeds will have more fibers and membrane attached to them. Wash this off, rubbing the seeds between your fingers to remove as much as the debris as you can. Then put the seeds in a container of water, and the good seeds will sink to the bottom. Remove what comes to the top, give the good seeds another rinse, and dry them on a plate or screen.

Lettuce and Greens

Radishes, lettuce, and Asian greens also produce seeds in pods after the plant has flowered. With these vegetables, too, it is best to let the pods dry on the plant. These plants, however, tend to dry from the bottom up, a few pods at a time. The dry ones are prone to shattering and spreading their seed all over the ground, so either bag the seed heads—literally putting a paper bag tied at the base over the plants to capture the seeds—or pick the dry pods on a daily basis. Old nylons or row-cover materials work well for bagging because you can still see what’s going on with the plant.


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