|Daniel, saving seeds from an over-ripe zucchini.|
I've posted about saving seeds a few times already--here, here, and again in my most recent post. The thing is, all of those posts are fairly general, or focus on a specific event, rather than the specific action of saving seeds. I feel very strongly about saving seeds, even though I'm fairly new to it. There's something autonomous about the action--yes, there are great seed companies out there, and I have written in praise of a couple Etsy seed sellers; nonetheless, saving seeds is a logical step in the cycle of growing. When I save seeds, it allows me to get to know the plant better. I learn to look at the fruit/plant health not just in terms of what will be useful for eating, but also in terms of quality of seed. Sometimes we forget that plants are not only food producers, but also self-perpetuators. Also, saving the seeds from something usually yields a lot more seeds than are usually in a seed packet.
Before beginning to save seeds, it is important to know whether the plant you wish to save from is an heirloom (or open-pollinated) or hybrid. Heirloom and open-pollinated plants produce seeds that will re-create the plant variety true to type. So if you have a Cherokee Purple tomato and save seeds from it, the seeds will grow into a Cherokee Purple when planted. Hybrid plants, although often seemingly strong and perfect, will produce seeds that will not have the complete genetic information from the plant; when planted, seeds from hybrid plants will often make a plant that reverts to the characteristics of one of the parent plants. For example, if you save seeds from a SunGold tomato and plant them, you may have a couple plants that are scrawny, a few plants that produce tomatoes quite unlike the SunGold (too small, and probably not very sweet), etc. When I was saving seeds last year, I didn't know about this, and saved a lot of SunGold seeds. Most of the plants from those seeds weren't strong enough to survive hardening off, and once I realized that I'd planted a hybrid, I got rid of the remaining 2 plants, not wanting to nurture a plant that would later disappoint me.
Once you know that the plant is open-pollinated or heirloom, you can proceed to saving seeds. Last year, I saved the seeds of sweet peppers and squash, seeds that I'd usually discard. (I later learned that squash cross-pollinates very easily, but not until I grew some strange--but edible--mystery squash.) So far, at Beardsley Farm we have saved the seeds of okra, zucchini, cucumber, and sunflowers. All of these have very evident seeds that are easy to save. All that it took to save the seeds was cutting or splitting the vegetable and taking out the seeds. We had to dry the seeds of the cucurbits, but the okra and sunflower seeds were already dry, so all we had to do was collect them. Also, you should select the seeds from the most ripe and most perfect fruit. If you have seen the seeds of a plant (during planting time), you know what they should look like as you collect them. For example, okra seeds are dark greenish-black, whereas in edible young okra, the seeds are white; as the okra pods mature and become too tough to eat, the seeds mature, too. Finally, when the okra pods dry out, the seeds are ready for saving. This process is similar with cucurbits--wait until they are ripe (for cucumbers and summer squash, they should be ripe beyond what is acceptable for eating), and then collect seeds, drying them out as necessary. Saving tomato seeds is a little more involved, but there are resources out there to help you with that, too.
Once you have saved the seeds, make sure they are dry and ready for storage. I've been storing my seeds in small jars or paper envelopes. The very things a seed needs to germinate--light, water, soil--are the opposite of what a seed needs to remain dormant. Saved seeds need dark, cool, and dry storage areas.
I wish I could write more about saving seeds; I have become quite passionate about it. I try to save many different kinds of seeds--just earlier in the week, I plucked a dried out marigold flower, and saved the seeds from it. There's something wonderful about noticing the cycle of plants and helping them continue it. Keep an eye open for a local seed swap near you, and start collecting seeds to trade with others.