Jennifer Schultz Nelson
Extension Educator, Horticulture
I'm sure it sounds corny, but one of the first "gardening lessons" I remember being given as a young girl was saving seed from marigolds. I remember my mom showing me how to pick the flowers that were dead and dried on the plant and put them in a brown lunch sack.
I also remember that brown lunch sack sat in a cabinet in our basement, and if you wanted to plant marigolds in the spring, you took some of the dried flowers from the sack. I loved to help break open the flowers and see all the tiny seeds inside.
It sounds a little crazy that all these years later I remember doing this with my mom, but I do. It's not a big momentous memory of some spectacular event, but just quiet moments with my mom. Gardening gives you a lot of these moments. If any of you wonder whether gardening with your children is worth the effort, I will tell you wholeheartedly it is.
Flash forward a few years, and in high school I bought some seed of the first white flowered marigolds. I grew them, and wanted to save seed for next year. Just like I did as a young girl, I picked the dead dried flowers and stored them in a brown lunch sack in the basement cabinet.
The next year when I grew those seeds, I was surprised at the results. Some of the flowers didn't really look like marigolds at all. Some weren't white, but a weird green color with petals that stuck out like spokes on a wheel, more like a daisy than a marigold. What in the world had I done wrong?
The problem was that I had saved seed from a hybrid. Hybrids are cultivars that are developed by crossing, or hybridizing, particular plants as parents. Then the seed from that cross is sold as a hybrid cultivar, a specific combination of genetic material from the parent plants. If you harvest seed from the hybrid plants, you are getting a new combination of the parent plants' genes, and that new combination may look absolutely nothing like the original hybrid.
So you may think that as long as a plant is not a hybrid cultivar, the seed is worth saving. Not so fast. You have some factors to consider. Just because a plant is not a hybrid does not mean that the seed you are saving is what you think it is. For instance, if you planted any combination of squash, melons, pumpkins and cucumbers in your garden, they all have the potential to cross-pollinate with each other.
This cross pollinating does not affect the quality of the fruit consumed that year. But the seed you save from that melon that was the best you ever tasted may not taste so great next summer if the seeds you saved were actually a cross of that perfect melon with the squash planted next to it.
So how in the world does anyone save seed from squash, melon, pumpkin and cucumber? In a commercial setting to produce non-hybrid seed, individual cultivars are separated by half a mile or more.
If you have figured out a plant that you'd like to save seed from, how do you do it? Each crop has its specific needs, but in general you need to wait until the flower and its fruit are fully mature. In some cases, especially with vegetables, you may need to wait until the fruit is way past the stage at which it would be normally eaten. For instance, a mature cucumber which contains ripe seeds will appear very large and usually yellow in the garden-- not the point at which you would want to eat it!
Some crops need specific treatment after the seeds are collected in order for those seeds to germinate. Tomato seeds, for example, have a gelatinous coating on them that contains germination inhibitors. Unless that layer is removed, germination cannot occur. This layer can be removed by just wearing away over time, by passing through an animal's gut, or through fermentation.
As a grad student one of my classmates studied tomato breeding, and he occasionally used fermentation to prepare seeds he harvested. The smell of big containers of tomatoes fermenting was enough to knock you over if you weren't prepared for it. Just think of rotting tomatoes on a hot summer day. Now multiply that by at least ten. That is how bad the smell was. But it was a necessary evil in preparing viable seeds for the next generation of tomato breeding.
There are various pieces of information available for specific crops, but in general seed stores best in a cool, dark, dry place. If seeds are not totally dry when they are stored, it is likely they will mold.
Seed saving has been used successfully for many crops over the years-- the varieties we call "heirloom" are here today because of seed savers. There are many groups out there that trade seeds, as well as tips and tricks on seed saving. Your local U of I Extension office can also give you some suggestions on how to save seed of your favorite vegetable or flower.