The Bounty Continues After The Harvest

DIY Seed Harvesting

Written and Photographed by Amy Grisak 

As seed prices increase, saving seeds is a cost saving way to make your garden even more economical. But there’s more to it than simply gathering them at the end of harvest season. It begins in the spring while making planning and purchasing decisions. Along with a few tricks along the way, and knowing which varieties to grow, your garden will be full of the vegetables you love the most.   

It’s important to first understand the difference between open-pollinated, heirloom, and hybrid plants and how they pollinate. 

To save seeds which will grow the same as the parent plant, use an open-pollinated or heirloom variety. Heirlooms are always open-pollinated; an heirloom variety is simply one over 50 years old and often passed down through families or regions. 

Open-pollinated plants are pollinated naturally through wind, insects, self-pollination, or even with a little help from a human with a paint brush, and they produce fruit or plants true to the parent plant. With the exception of cross-pollination with a similar species, saving seed from open-pollinated plants will grow the same variety the following year. 

Hybrids are developed to combine the best characteristics of each parent plant to produce offspring which performs well and maintains desirable features. However, subsequent generations do not grow the same as F1 hybrid, therefore hybrids are not a good option for seed harvesting. 

Vegetables either pollinate by self-pollination or cross-pollination, which is an important consideration when organizing a garden. Self-pollinated plants are monoecious, meaning they contain male and female parts on the same plant, therefore, a second plant is not required to create seeds. On the other hand, dioecious plants are distinctly male or female. For example, an elderberry bush is either male or female.

Most garden plants, such as tomatoes, squash, pumpkins, peppers, lettuce, beans, corn, and peas, are self-pollinating. The trick is ensuring cross pollination doesn’t occur, particularly if more than one variety is grown in a garden. Cross pollination will result in a hybrid which will not grow true the following season. 

The easiest way to prevent cross-pollination is to plant a single variety of each plant. If other varieties are present, contain the pollen by covering the flowers to prevent bees from carrying pollen from a different variety nearby. Use a simple cage covered with screening or floating row cover material to segregate single plants such as broccoli, kale, lettuce, eggplant, and similarly sized plants during flowering. When flowering is complete, the barrier can be removed for the remainder of the season. 

Some plants, like tomatoes and peppers, have “perfect flowers,” meaning the male and female components are not only on the same plant, but also within the same flower. These are less likely to cross-pollinate with another variety, but it’s still wise to take measures to ensure there’s no risk of cross-pollination. Use a mesh bag or wrap the flowers with the lightweight floating row cover to keep them out of reach from pollinators. 

Members of the squash family, also called cucurbits, require more attention. Pumpkins and squash will readily cross-pollinate if planted in the same area. In this situation, manually pollinating the plants with a small paintbrush can help ensure self-pollination. A mesh or lightweight (never plastic) bag placed over the flowers is still needed to prevent any accidental pollination. Then, in the early morning, just as the flowers open, use a small paintbrush to collect pollen from the male flowers and transfer it to the female flowers, which are easily identified by the small fruit behind the blossom. After pollinating, replace the bag or tape the blossom shut.

Corn is even more challenging unless there is adequate space between neighboring corn crops as it is wind pollinated. According to Ohio State University, corn varieties should be planted at least 600 feet apart. If this isn't possible, plant with a privacy fence or a building separating the corn patches to reduce the risk of potential cross-pollination. 

After preserving the variety of plants to grow the following spring, the fun part is collecting the seeds during the summer. For most of the varieties, it’s simply a matter of harvesting the vegetable after it has reached complete maturation. 

In the cucurbit family, vegetables are cut in half, then the seeds are scooped out, rinsed under water, and allowed to dry thoroughly on a rack or paper towel. Peppers, particularly sweet varieties, should develop into a deep red or orange before similarly cutting in half, scooping out seeds, and allowing complete drying prior to storage.

On broccoli, cauliflower, kale, lettuce, and spinach the seed heads must mature on the plant, resembling a stalk of tiny pea pods once complete. The easiest harvest method is to pull the entire plant, hang it upside down to dry completely, then twist the pods over a sheet of paper to collect the seeds. 

Peas and beans should be left in the garden until the pods are quite dry and crunchy. Prior to the first hard freeze, the entire plant should be harvested and hung upside down until the seeds rattle inside the pod, which can take weeks. Once reaching this stage, the pods can be cracked open to remove dried seeds.

Tomatoes are different than most other garden crops due to the pulp encasing the seed, but there is a simple trick for separation. After selecting fully matured fruits, cut the tomato in half, scoop out the seeds and place them, pulp included, in a pint-sized canning jar. Fill it roughly half-way with water then place a cheesecloth or paper towel lightly over the top. In two to four days, it should start fermenting and the mixture might smell during this process, but the seeds are ready once a layer of mold can be seen on the floating bits of pulp and the seeds have sunk to the bottom of the jar.  At that point, the pulp should be skimmed off, the seeds collected in a strainer, then thoroughly rinsed before setting out to dry on a paper towel for several days before storing in an envelope. 

In low humidity areas, like Montana, seeds can be successfully stored for years.  Thoroughly dried seeds should be stored in an envelope or jar in a cool, dark location. While these should last years, added longevity can be achieved by storing them in the freezer. Add a desiccant packet in the envelope or jar for three days to remove any remnant moisture before freezing. 

Harvesting seeds adds to the economic advantages of gardening, ensures preferred varieties are grown year after year, and can add another enjoyable step for gardening enthusiasts.  So, identify those favorites this spring and take the steps to save seeds this fall.