Genetics of good seeds
Long before seed companies existed, gardeners collected seeds from their best-performing plants to start next year’s garden.
Now, it’s convenient to just purchase seeds and plants each year, but there are still good reasons to collect your own seeds.
Saving seeds allows gardeners to fully participate in the circle of life in a garden, and it also lets them select seeds from plants with desirable characteristics to plant again. If a particular plant did especially well in your garden this year, it probably has the genetic predisposition to thrive again in this climate and soil.
Seeds also are fun to give away as gifts, since they really came from your home and hard work. They’re cheaper than purchasing new seed every year, and you can control the variety of plants you grow in your garden.
To make the most of saving your own seeds, it’s helpful to know the basics of plant genetics, how your garden plants are pollinated and whether you have hybridized varieties.
If you reach way, way back in your mind and transport yourself to high school botany and biology, the lesson of Gregor Mendel’s genetic experiments with the pea plants can help you (by the way, thanks to Mr. Rieniets and Mr. Schaefer for that knowledge). When you cross two parents, you have a variety of possible outcomes in the first generation of offspring, depending on the dominant and recessive traits coded in the alleles (the variation of the same gene). In humans, these alleles can code for traits such as eye color or blood type, but in plants they could stand for other traits such as color or size.
Hybridization is tricky and requires far more patience and time than I’m willing to commit. Basically, hybrid plants are the result of crossing two highly specialized (inbred) varieties. The first generation of this offspring will be bigger, better and more improved than the parents. This is called “hybrid vigor,” in this first generation.
Think of what happens when a male donkey and a female horse breed. Their offspring is a mule, which is taller and stronger than either parent. The same thing happens with plants. The result of hybridization is a larger, better-performing plant.
How do you know if you have a hybrid plant? Heirlooms and most open-pollinated plants are not hybrids. Often, hybrids will have fancy names, such as “Better Boy” or “Early Girl” in tomatoes, because they’ve been hybridized to produce more fruit, earlier and with more disease resistance. It can take years of selecting for specific traits to produce what’s called a “true line,” or a reliable set of genetic traits that have resulted from self-pollinating that plant repeatedly.
If your original seed package says “F1 hybrid,” you planted the first generation of plants produced by cross-pollinating the original parents. You could end up with a lot of different combinations (and disappointment) if you save seeds from this generation. It won’t “produce true,” as some say. They could revert to the parent genetics, express some hidden recessive genes, or be totally sterile. But if you have open-pollinated seeds, or seeds from plants that self-pollinate, you can successfully save seeds.
Understanding pollination is vital to get desirable results. Sometimes it’s impractical for a gardener with a small plot to save seeds. To avoid cross-pollination between varieties of some vegetables, you need at least 1/4 mile separating those varieties, according to Colorado State University Extension. But some garden plants are self-pollinating, such as tomatoes, beans and lettuce, so you don’t really have to worry about this problem in smaller areas.
Some plants are pollinated by insects, like curcubits (cucumbers, melons and squash), peppers, and cruciferous vegetables (cabbage, Brussels sprouts, kohlrabi, broccoli, etc.). If you want to save seeds from these plants, only plant one variety. Even then, the possibility of a bee pollinating your cucumber with the neighbor’s cucumber pollen exists.
Harvesting viable seeds is important and can be a little tricky. With juicier vegetables and fruits, you want to let them over-ripen, but not rot. If it starts to decompose, the increased temperatures can damage the seeds.
Then you’ll need to scrape out the seeds, rinse them off and dry them out before storing them. I dry them on paper towels or newspapers on the counter.
With seeds heads, you want to let them completely dry, but catch them before the wind sweeps them away or they fall on the ground. It’s difficult to time this correctly, so with smaller seeds such as lettuce or cosmos, I take a paper bag and tie it over the seed heads so they will drop into the bag when they’re ready. Don’t use plastic bags as they retain moisture and will cause problems.
Properly storing seed also is important, so you don’t waste all your time and effort. Keeping light and heat away from seeds makes them last longer. According to “The New Seed Starters Handbook,” most seeds stored between 32 and 41 degrees Fahrenheit usually keep well.
You can keep seeds in your freezer, but make sure they are completely dry first, or the moisture in the seeds will expand and destroy them. Make sure to label them so you know what you kept. It’s easy to slip them into envelopes, old film canisters or small paper bags for storage.
How long do seeds last? Generally their germination rate declines over time, no matter what kind of plant they came from. Some seeds last longer than others, with lettuce seeds lasting at least five years and peas only lasting a year or so, according to the handbook.
For more information, I highly recommend reading Nancy Bubel’s “The New Seed-Starters Handbook,” as it has all the information you could want to save your seeds and grow your garden year after year.