By late summer a garden starts doing something it kept hidden all spring. It goes to seed. The lettuce shoots up a tall stalk, the beans swell and dry in their pods, the sunflowers droop their heavy heads. It is easy to read all of this as the garden winding down. It is closer to the truth to say the garden is packing next year's lunch. Learning to save seeds is one of the oldest, cheapest, most satisfying things you can do out there, and you can start with what is already standing.
Here is a plain guide to saving seeds from your garden, including the one catch worth knowing before you begin.
Start with the one catch
Before you save a single seed, check whether your plant is an heirloom or open-pollinated variety, or a hybrid (often labeled F1 on the packet or tag). Seeds saved from heirloom and open-pollinated plants grow up looking like their parent. Seeds saved from a hybrid usually do not. They scatter back into the two plants that were crossed to make them, so you never quite know what you will get. It is not dangerous, just unpredictable, and it is the reason a saved-seed tomato sometimes surprises you. If you want next year to match this year, save from heirlooms.
The easy ones to start with
Some plants practically save themselves, because they pollinate their own flowers and do not cross much with their neighbors. Beans, peas, lettuce, and tomatoes are the classic first four. Peppers are simple too. If you grew sunflowers, zinnias, marigolds, or let some cilantro flower, those are generous as well. Skip squash, cucumbers, and corn for now, since they cross readily with other varieties nearby and take more care to keep true.
Beans and peas: let them rattle
The simplest seeds of all. Leave a few of the best pods on the plant and stop picking them. Let them stay until they are brown, papery, and rattle when you shake them. Then bring them in, split the pods open, and tip the dry seeds out. That is the whole job.
Lettuce and herbs: wait for the fluff
Once lettuce bolts and sends up its stalk, let it flower and go to seed. The seed heads turn dry and a little fluffy, like a tiny dandelion. Snip them into a paper bag and give it a shake. Cilantro, dill, and basil work the same way. Let the flower heads dry on the plant, then collect the seeds from the spent blooms.
Sunflowers: let the head hang
A sunflower tells you it is ready by drooping and browning on the back of its head. Let it dry on the stalk if the birds will let you, or cut it and hang it somewhere airy indoors. When it is fully dry, rub your thumb across the face and the seeds come loose in handfuls. Keep some for planting, and leave a head or two out for the birds, who earned it. (Sunflowers make so many seeds, and hold up so much of the garden, that we named a whole book after one. Sunny Plants a Party has the biggest heart in the garden, which feels about right for the plant that feeds half of it.)
Tomatoes: the one extra step
Tomato seeds come wrapped in a slippery gel that stops them sprouting inside the fruit, and you have to remove it. Scoop the seeds and their gel into a jar with a splash of water and leave it on the counter for two or three days, stirring once a day. It will look unlovely and smell a little sour. That is the point. Once the gel has broken down, rinse the seeds in a sieve until they are clean, then spread them on a plate or paper towel to dry.
Drying and storing
Whatever you save, the rule is the same. Seeds must be bone dry before they go into storage, or they will mold. Spread them in a single layer somewhere warm and out of direct sun for a week or two, until they snap rather than bend. Then store them in a paper envelope or a small jar somewhere cool, dark, and dry. Label every one with the plant and the year, because you will not remember by spring, and most seeds stay good for a few years when they are kept this way.
A season worth sharing
Seed saving is a fine job to do beside a child, because it is slow and forgiving and a little bit like a treasure hunt. Let them shake the bean pods and rub the sunflower head and tuck the envelopes into a box. You are handing them a quiet idea along with the seeds, that a garden is a circle, not a straight line, and that the end of one season is just the start of the next. If you would like a story to read once the seeds are put away, the ebook of our first book, Moss Finds His Spot, is free when you join our list, along with one unhurried note a month if you would like the company.