Many of the vegetables we grow in our gardens produce seeds that, if harvested and stored correctly, have the potential to grace us with free plants. And the end of summer is the perfect time to start collecting them.
A few notes: Make sure the plants you are collecting seeds from are heirloom or open-pollinated varieties. These are plants in their original forms whose seeds will produce plants with the same qualities as their parent.
Hybrid varieties, on the other hand, are created by crossing two or more different types to capture the best qualities of each. Attempting to grow seeds collected from hybrids will yield a disappointing harvest, as the resulting plants will not have the expected attributes but instead will have the traits of only one of the parents, and there is no way of knowing which it will be. For this reason, it is best not to grow seeds from supermarket produce.
Many plants cross-pollinate in the garden when pollinators, other insects, animals, and the wind transfer pollen from one plant to another. To ensure that the seeds you collect grow into plants that match their parents, different varieties of the same crop should be kept between 100 feet and a mile apart, depending on climate, weather, and other variables. This is often impractical, if not impossible, in the home garden.
To avoid cross-pollination surprises, plant only one variety from the category of plants you plan to harvest seeds from. If you want to save tomato seeds, for example, grow only one type of tomato in your garden.
If that seems too limiting, go ahead and experiment, knowing that even if it is cross-pollinated, both parents are heritage varieties that you selected and planted. They will probably be fine even if they are not what you expect.
Store all seeds in a cool, dry place in a covered glass jar or paper envelope away from ripe fruit, which will affect seed germination. Temporarily adding a silica gel packet to the jar will remove any remaining moisture, but remove it after a couple of days to prevent it from drying out too much.
Here’s how to collect and save seeds from the most common home crops.
At the end of the growing season, the lettuce will sprout or send out a flowering stalk that will develop seed heads reminiscent of dandelion puffs. When the puffs are dry, remove the entire stem, place it in a paper bag, fold the top over, and shake it off. The seeds will detach from the flower and fall to the bottom of the bag.
Parsley is a biennial plant with a two-year life cycle that produces only edible foliage in the first year and leaves and flowers in the second. Allow those flowers to remain on the second year plants until they turn brown and brittle. Cut them off the plant and store them in a paper bag to dry completely for a couple of weeks. When you remove them from the bag, rub the flowers between your fingers to separate the seeds, then blow on the light, dry plant matter and discard.
Beets and Carrots
These biennial plants produce seeds only in their second year, after a period of vernalization or cold storage. In areas with cold winters, simply leave the plants in the ground over winter.
In hot climates, you’ll need to “winter” indoors: At the end of the first season, cut back the foliage to 2 inches, carefully pull the roots out, and store in a cool refrigerator or cellar over winter. Replant them outdoors the following spring.
When the leaves of second-year beet plants turn brown, remove the seed stalk from the top of the plant and place it in a paper bag. Store in a cool, dry place for at least two weeks, then shake the bag well to separate the seeds. Pour them into a plate, then blow on them to separate the chaff.
Allow the second year carrot flowers to dry on the plant, cut them off and dry them further in a paper bag for a week or two. Shake the bag well and pour the seeds into a plate, blow on them to separate the chaff.
Select the prettiest bell pepper from your healthiest plant and leave it on the plant until it is overripe and shriveled. Cut it in half and remove the seeds, discarding any that are discolored or otherwise undesirable. Spread the seeds out in a single layer on paper towels and let them dry in a warm place away from direct sunlight. Mix the seeds from time to time to ensure even drying, which should take about a week.
Allow an eggplant to over-ripen on the plant until it hardens and shriveles, losing its shine and color. Cut it open, remove the seeds and place them in a container of water. Swirl the water with your hands to separate the seeds from any meat attached to them. Strain, then towel dry the seeds and spread them out on a towel or screen to dry, stirring daily for up to a month until completely dry.
Because green beans produce a continuous crop throughout the season, enjoy the first flush or two, then leave the developing pods on a plant until they are completely dry and brown. You’ll know they’re ready when they play like maracas. Cut the pods off the plant, place them in a cool, dark place to dry further, and then remove the seeds. Discard any that appear discolored or damaged, and spread the rest out on a towel for a few days to harden.
There are two ways to save tomato seeds: the right way and the easy way. Full disclosure: I like easy and I’ve done it with the shortcut. Your results may vary.
Start by cutting a tomato in half, then squeeze its seeds and pulp over a bowl.
Fermentation improves germination rates and kills some seed-borne pathogens that could make plants sick. To ferment seeds:
1. Place a slightly askew lid on the container and let the seeds sit in their juices without touching them for three days.
2. Pour the contents of the container, which may be covered with white film, into a larger container and add water equivalent to at least 3 times the volume of the seeds.
3. Shake the water by hand and pour out the liquid. You will notice that most of the seeds will have sunk to the bottom of the container; are the viable seeds.
The ones that float are rags, so pour them in with the juice, pulp, and water. Repeat the rinsing process two more times.
To ensure pathogens are killed, soak the seeds for 30 minutes in a solution of 90% water and 10% bleach, then rinse thoroughly. Spread the seeds out on a towel and let dry for about a week, stirring occasionally.
Or you can just let the whole mess of seeds and pulp dry in a dish in the open air for a week or so, then scrape or remove the seeds.