Though Your Garden May Be Fading, It's Still Filled With Seeds of New Life

• Kelly Senser
• Oct 01, 1999

Autumn’s here and it’s time to harvest. Though your flowers may have faded and your plants begun to droop, your garden remains filled with promise. Thousands of seeds are ripening, and they could provide the foundation for next year’s expansion of your wildlife habitat. Collecting them costs nothing and may offer you access to native plants that are not readily available at most local nurseries.

“Habitat restoration is critical for wildlife in urban and suburban settings where commercial and residential development has eliminated most natural areas,” says Craig Tufts, chief naturalist at the National Wildlife Federation. While the seeds from all types of backyard plants can be collected and sown, native species support 10 to 50 times as many varieties of indigenous wildlife as do nonnative plants. Native plants also require less fertilizer, less water and less effort in controlling pests. That’s why growing such species in your yard not only ensures preservation of valuable plants but also the diversity of animals and insects that depend on them.

Before you begin collecting, take the time to learn more about the process so that your initial efforts are successful. Knowing how to identify a mature seed is one key element. (For practical purposes, the examples that follow will focus on nonfruit-bearing perennials.)

As a rule of thumb, seeds of plants are ripe about a month after flowers fade, when seed pods--which form in place of blooms--and stems turn brown and become dry and brittle. Seeds may not be viable if harvested earlier, as the embryos inside them need time to fully develop.

Keep an eye on your plants throughout the growing season. The seeds will mature anytime from spring until fall.

A dry, sunny afternoon is the best time to harvest. (Rain or dew on seeds can promote mold in storage.) While some seeds such as New England aster can be plucked by hand or shaken directly into a collection container, you should first cut the seed pods from plants such as cardinal flower and blazing star and allow them to air dry in paper bags for a few days. These seed capsules can then be shaken until the seeds fall out.

Noting that Mother Nature does most of her planting in late summer or fall, some experts recommend gardeners sow what they harvest right away. Seeds that benefit from such quick planting include pasque flower, columbine and marsh marigold. Still, other perennials, such as purple coneflower and yellow jessamine, can also be stored safely for future planting in winter or spring. If properly cared for, the stored seeds may grow at rates equal to or better than those that are sown immediately. Understanding the germination requirements of your plants will help you determine whether or not storage is appropriate.

Because plant debris left on or around seeds in storage may harbor insects, fungi or moisture that can damage the seeds, be sure to thoroughly clean and dry what you have collected. One way to winnow out chaff is to pour seeds from one container to another while blowing gently on them. Screens or sieves can also be used.

To dry out the seeds, simply lay them down indoors on newspaper. In air-conditioned environments with low humidity, seeds should become dry enough for storage in a couple of weeks. In homes without air-conditioning, where humidity will prevent seeds from drying sufficiently in the open air, silica gel can be used to absorb excess moisture and to prevent mildew from developing later in storage containers. Seeds packaged in paper envelopes and placed in sealed containers with an equal weight of the substance dry in about one week´s time, after which you should remove the silica gel to avoid overdrying and killing the seeds.

“For the longest, low-tech home storage, seeds can be dried then stored in jars in the freezer,” says Jack Rowe, manager of the nonprofit Seeds of Texas Seed Exchange. You can also place containers in a cool, dark cupboard or the vegetable crisper in your refrigerator. Household items appropriate for seed-storing include screw-top glass jars, plastic or metal film containers, cans with metal lids and prescription medicine containers.

Experts emphasize the importance of labeling the seeds you have collected. “Nothing is more frustrating than ending up with several bags of mystery seeds,” says botanist Suzanne Ashworth, a volunteer curator for Seed Savers Exchange, a nonprofit group based in Iowa. Be sure to note the plant names and harvest dates on each of your storage containers.

Sharing the information and seeds you collect is valuable too, according to Rowe, who encourages people to seek out local native-plant societies, gardening clubs or seed exchanges in their communities. By joining one of these organizations, you can interact with other enthusiasts who share your passion for natural gardening. These groups also tend to be good places to obtain native plants or seeds that are not yet commercially available. 

Wild seed collection on private land may also be an option, provided the landowner has granted you permission. But experts caution against being greedy. “By gathering as many wild seeds as you can, you are not trying to protect what is growing naturally,” explains Ashworth.  Conservationists also point out that it is usually much easier to preserve existing natural areas than it is to restore them.

According to the Center For Plant Conservation, a St. Louis-based organization dedicated exclusively to preventing the extinction of rare plants, one-quarter of U.S. species--roughly 5,000 native plants--are currently “of conservation concern,” plagued by development, overcollecting and invasion by exotic species. Taking special care not to disturb such plants in the wild and educating others about their importance is key to their survival.

“So often we forget that the most intelligent response to finding a new plant population or community is to do nothing--just look and enjoy,” says Rowe. “By focusing your attention on your  yard and the native-plant seeds available there, you can help support biological diversity in your community.”

Find out how you can turn your garden into a Certified Wildlife Habitat.