Extension Educator, Horticulture
You've found it - that perfect tomato. You love the size, flavor and texture, but you are not quite sure what variety it is. Do you just let cindertomato slip away? Saving seed seems like a simple process. Eat a few raspberries or walk through the woods - seeds want us to save them or at least move them around.
So can you save seed and get the same plant next season? It all depends. Depends on the parent's genetics and whether the pollen came from the family or the mailman. Generally in order for seeds to develop, pollen has to be transferred to the female part of the flower either by insects, wind or gravity. If the parent's genetics is fairly stable through generations of inbreeding and the pollen to produce the seeds comes from the family, then the seeds can be saved, planted the next season and will produce a plant very similar to last season's plants. Peas, beans, lettuce, tomatoes, peppers and eggplant are self-pollinated. Seeds from these can easily be saved unless they are listed as hybrids.
Some plants are open-pollinated. They cross-pollinate but are not hybrids. Generally if these are grown in isolation, they produce offspring that is similar to their parents. Many older cultivars and heirlooms are open-pollinated and seeds can be saved with some certainty of getting the same plants.
The tricky part to saving seed is if the parents naturally cross-pollinate with other relatives or if the plant is a hybrid or a cultivar (cultivated variety). With hybrids any saved seeds will produce wildly different offspring from their parents. It's not recommended to save seeds from hybrids. If you are into the unpredictable, however, then seeds saved from hybrids are your dream come true. Keep in mind some cultivars are patented and it is illegal to propagate them.
In order to save seed from cross-pollinated, non-hybrid plants, the plants will need to be isolated by at least 200 yards if insect pollinated or at least a mile for wind pollinated plants. Crops normally cross-pollinated by insects include carrots, parsnips, cole crops (cabbage, broccoli, mustards, collards, kale, kohlrabi, cauliflower, turnips, radish and Brussels sprouts) and members of the squash family (summer and winter squash, pumpkins, cucumbers and melons). Plants cross-pollinated by wind include beets, chard, spinach and corn. Different varieties of cross-pollinated plants will easily cross with each other and their relatives including the neighbor's plants. Although it does not affect the fruit borne this season, if you save the seed and plant them next year, the plants that come from these seeds will be different. So will the fruit. A pumpzini or a zucpkin comes to mind.
Plants that are biennial (carrots, beets and cabbage) will not flower until the second year, so they will have to be left in the ground over the winter to produce seed the next year. Probably more trouble than it's worth.
So you want to save seed from cindertomato? Allow the tomato to ripen on the vine. Cut the tomato open and spoon the pulp and seeds into a glass container. Alert the family and set the pulp and seeds aside for one or two days to ferment, then spray water into the fermented solution. Clean seeds will drop to the bottom of the container. Pour off the sediment. Several rinses may be necessary. Then spread the tomato seed out on paper towels to dry. After seeds are dry, package, label and date for storage in a cool (refrigerator), dry location.
Or try Sandy's lazy (energy efficient) method. Take your favorite tomato. Place it on the ground where you want the plants for next year. Leave it there over the winter. Next spring you will have plenty of seedlings pop up with little effort from you.