Seed Saving Basics
Article By: Jessica Warren, ANR Agent, Camden County
As interest in gardening has increased over the changes and challenges of the last two years, so has an interest in seed saving. There are many reasons that people get interested in saving their own seeds. For most people they enjoy learning and gaining more in-depth knowledge about the plants that they work with. Other reasons include the opportunity to influence crop traits, regional adaptation, preserving heirloom varieties and saving money.
The first thing that you need to know about saving seeds is that there are two broad categories of seed varieties – open pollinated and F1 hybrids. Hybrid seeds are a cross of two parent varieties and will not breed true. This means that if you save those seeds, the plant that grows from them may not look or taste like the plant you harvested the seeds from. Open pollinated seeds are the only seeds recommended for saving. There are two categories of open pollinated seeds – self-pollinating and cross-pollinating. Self-pollinating seeds are much easier to save, and if you’re just starting your seed saving journey I would recommend starting with self-pollinating varieties. Self-pollinating crops include peas, beans, tomatoes and peppers. Cross-pollinating crops such as broccoli, cabbage, kale, collards, corn, carrots, beets, squash, cucumbers and melons, require isolation to produce seeds that are true to type. This means either physical isolation by not planting another plant or variety in the same family within a prescribed distance, or tying flowers shut and hand pollinating them to ensure they don’t get pollinated by a different variety. Today we’ll only be discussing self-pollinating plants.
There are three types of fruits/seeds to harvest for seed saving. Fleshy fruits such as tomatoes, berries and figs, dry fruits like grains and grasses, and dry pods or flowers such as beans or basil. Each of these have different methods to collect and prepare the seed for saving.
Some seeds require a fermentation process to remove germination inhibiting substances from the seed coat. The fermentation process mimics the natural process that takes place as fruits rot or pass through the gut of an animal. Fermentation can increase germination rates and kill some seed borne pathogens. Fermentation is required for saving seed from tomatoes and cucumbers. To start the fermentation process, place seeds and pulp in a container. If the seed/pulp mixture is too thick to stir, you can add a little water. Place the container in a warm location (72-86 degrees F) and stir the mixture 2-3 times per day. Fermentation takes between 48 and 72 hours. You may see a small amount of white mold on the mixture – it’s not harmful and can be stirred in. Closely monitor the seeds for sprouting. Sprouting is a sign that the seed has soaked too long. If the gel around the seeds is completely gone, the process is finished. Once the fermentation process is completed, rinse the pulp from the seed using a strainer and pressurized water. After rinsing, pat the bottom of the strainer with a cloth towel and let it dry for a few hours with the seed in it. Next, spread the seeds on a plastic, glass or ceramic plate (do not use paper towels or wax paper on the plate). Spread seeds in a single layer and dry in an airy, dry location such as an air-conditioned room. Keep the humidity between 20% and 40%. The drying process usually takes 2 weeks or more. Make sure to label your seeds – especially if you are saving seeds from more than one variety in the same family.
Different plants may have different harvest methods. To harvest tomato seeds, allow fruit to ripen fully and scoop out the seeds along with their surrounding gel before you eat or cook the tomatoes. Follow the fermentation process described above. To harvest pepper seeds, allow some fruit to stay on the plant until they become fully ripe and start to wrinkle. Remove the seeds from the peppers at this point and spread them out to dry. If beans or peas are on your seed saving list, allow the pods to ripen on the plant until they are dry and brown, and the seeds rattle in the pod. Strip the pods from the plants and spread them out to dry indoors. Dry the pods for at least two weeks before shelling, or leave the seeds in the pods until planting time. When saving seed from herbs or other flowers avoid deadheading and wait for the petals to drop and expose the dry seeds. Remove the entire flower. There are a few different methods you can use to remove the seeds from the other flower debris. You can place the flowers in a paper bag, hold it shut, shake it vigorously, pick out the clean seeds from the bottom of the bag and discard the chaff. Alternatively, you can spread the flowers on a paper towel and rub gently, use tweezers to pick out the clean seeds and then discard the chaff. Often my favorite method is to crush the dried flowers in your hands and blow gently to remove the chaff. If you are working with seeds that have fluff attached, such as milkweed seeds, you can use a piece of old stocking to gently rub them to separate the fluff from the seeds. Examine all of the seeds that you collect and only save the largest, plumpest seeds. Small deflated seeds are not viable.
Proper seed storage is one of the most important steps in seed saving. Clean, dried seed should be stored in airtight containers such as glass jars with gasketed lids. For small quantities of seeds, you can place each variety in a paper envelope and put several envelopes in an airtight jar. Label each envelope and jar clearly with the variety of plant as well as the date of harvest. Store in a cool, dry, dark place. A climate-controlled closet or cupboard is good, an airtight glass container in the refrigerator is even better. Plastic does not act as an effective moisture barrier. Always let refrigerated seeds warm to room temperature before opening the container. Depending on the quality of preparation and the species, most seeds remain viable for 2-5 years in storage. You can test the germination rates of your stored seed by placing 25 seeds on a wet paper towel, rolling it up and placing it in a plastic zip top bag with some small pinholes in it. Keep this in an area that is consistently at least 75 degrees F. At day 7 and day 14 unroll the paper towel and see how many of the seeds have sprouted. At the end of day 14, take the total number of sprouted seeds and divide the number by 25. This will give you your germination rate (for example if 23 seeds sprouted, 23/25=.92 or a 92% germination rate). Happy gardening!