By Sam Burbach, Education & Programming Coordinator – 1/27/2022

Each year, the last Saturday of January is celebrated by gardeners as National Seed Swap Day. This “national day” began when Kathy Jentz of Washington Gardener Magazine organized a seed exchange on January 26, 2006 in Washington, D.C. The event was so successful that it continued as an annual event, and even spread to other cities, eventually becoming National Seed Swap Day.

Sharing seeds is a great way to pass on plants to friends, family, and other gardeners. More importantly, it helps promote genetic biodiversity and preserve heirloom varieties. Saving seeds is easy and exchanging them can be a low- to no-cost way to add new plant varieties to your garden. If you already save and share seeds from your garden, that is great! If you’re new to collecting and saving seeds, there are a few things to keep in mind as you pick out seeds you intend to collect from.


Self-pollination vs. Cross-pollination

Pollination is the transfer of pollen from the male anther to the female stigma to fertilize the ovary to produce fruit and seeds. For seeds to grow into plants like the parent, they need to be open-pollinated plants that are self-pollinated or cross-pollinated by other plants of the same variety.

Flowers that are self-pollinated are fertilized by pollen of the same flower. Self-pollinated open-pollinated plants are the easiest to collect seed from because they are the most likely to produce true-to-type seeds. Beans, peas, peppers, and tomatoes are good self-pollinating plants to collect seed from.

Cross-pollination occurs when pollen is transferred from the flower of one plant to another, and the two plants may not be of the same variety. Two varieties of the same species of plant can cross-pollinate through insect or wind pollination, thus producing hybrid seed unintentionally. For example, if you plant two different types of squash in the garden, they can easily cross-pollinate from insect pollinators. The squash on each of the plants will grow how you expected them to grow, but the seeds produced inside of each of those fruits will be a hybrid that will not grow true to the squash you collected it from. If you are planning to save seed from a plant that cross-pollinates easily, such as corn, cucumbers, melons, squash, and pumpkins, you should only plant one variety in the garden to prevent unwanted hybrids.

Collecting seed

Seeds need time to mature before they are viable to produce new plants, so it is important to harvest seeds at the correct stage. Many fruits and vegetables that we eat do not have mature seeds at the stage that we eat them so a few fruits should be left on the plant to mature into viable seed. For example, to collect seeds from a pea or bean plant, a few pods should be left on the plant to dry before harvesting. On the other hand, tomato seeds can be successfully saved from a fully ripened fruit that you are about to eat or cook with.

Collecting seeds from flowering plants is simple but will require you to hold off from dead-heading a handful of flowers. The flowers left on the plant will produce a fruiting structure and can be harvested once it is dried out.

Storing seeds

The key to storing seeds is keeping them dry and cool. Seeds should be allowed to dry out completely before storing them in an airtight container or paper envelope and placing them in a cool, dry location. Make sure that you label each of the seeds as well!

Swapping seeds

Seeds can be shared with family, friends, and other gardeners on a personal level or through seed swap events. Some seed swaps are found online as well so you can share seeds through the mail.

Saving seeds can be fun, easy, and an inexpensive way to get new plants or share plants with others. If you’ve saved seed from last year’s garden, consider surprising a family member or friend with a small packet of seeds this Saturday for National Seed Swap Day! If you’ve never saved seeds before, give it a try this growing season so you can participate next year!


Resources & additional information about saving seeds:

Seed Savers Exchange: https://www.seedsavers.org/how-to-save-seeds

Seed Saving Chart: https://www.seedsavers.org/seed-saving-chart