Wednesday, September 3

Free flowering

Collecting and storing seeds

Saving seeds is a great way to ensure abundant blooms next season. Photo/Ann Tice

Summer is over. Did you blink and miss it, too? It seems that only last week I was getting the first back strain of the season bringing containers up from the basement. Now it's time to start my annual fall ritual of collecting and saving seeds for next year.

Saving seeds is a time-honored tradition with me. I'm cheap, and saving seeds gives me next year's plants for free.

Not all seeds are worth saving

Today's hybrids have been bred to have specific traits we find desirable. But their seeds are often sterile or at least won't breed true; they produce plants with different, often inferior characteristics from the parents. Other seeds may have been open pollinated — fertilized with the pollen of a different variety of the same plant growing nearby. Once again you get an unpredictable mix of traits that may not be much like the plant they came from.

What kinds of seeds are worth saving then? Good candidates include those plants marked ‘standard’ or heirloom varieties that you can be fairly sure haven't been cross-pollinated.

Because setting seed keeps the plant from producing more flowers or fruits, early in the season select a few of the most robust, disease-free plants — with the most beautiful flowers and most flavorful fruits — for seed harvesting. Keep deadheading and grooming the rest so the garden will stay bright and blooming, but allow your seed plants to fully ripen and mature. Pod plants like beans are ready when the pods are brown, dry and brittle. Most flowers will fade and get some sort of puffy top or heavy shell. Fleshy fruits will start to shrivel and become very soft when their seeds are ready.

The dry method

Most flower and herb seeds, as well as beans, peas, and onions, are collected and prepared using the dry method. Let the seed structures remain on the plant as long as possible, then remove and continue to dry them by spreading the seed heads in a single layer on a screen or tray in a dry, well-ventilated area. Blow away chaff or remove pods as the seeds become thoroughly dry. For extremely tiny seeds, such as those of lobelia, poppies or carrots, put the dry heads into a paper bag to catch the seeds as they fall.

The wet method

The seeds of some plants, like these rudbeckia, need exposure to cold in order to germinate successfully. Photo/Proven Winners

All the fleshy fruits — tomatoes, melons, cucumbers, roses (yes, they're part of the apple family) — are cleaned and prepared using the wet method. Scoop the massed seeds out of the fruits and place them in a container of warm water. Let this slurry ferment for a few days, stirring daily. The fermentation causes the good seeds to sink to the bottom of the container while the bad ones float to the surface. Pour off the pulp and bad seeds and layer the good seeds on paper towels to dry thoroughly. When your seeds are completely dry, put them in clearly labeled envelopes, noting the plant and variety and the date the seed was put into storage. Put these envelopes in a large jar and pop it into the freezer for 48 hours to kill any pests, then transfer the jar to a cool, dry place like the produce drawer of the refrigerator. I like to put a small cloth bag filled with dry powdered milk in the storage jars to absorb moisture. Don't use silica gel, though. It is too efficient and will draw the life right out of the seeds.

Speaking of cold, the seeds from many plants native to chilly climates — such as iris, aster, rudbeckia, buddleia and lavender — need a period of stratification (exposure to cold) to germinate successfully. Put these seeds in damp sand or sphagnum moss in a plastic baggie in the produce drawer of your refrigerator. The rule of thumb is 90 days in a moist, cold environment, but exact time and temperatures can vary with specific plants. The seed company Thompson and Morgan offers a detailed and comprehensive seed germination guide on their Web site at www.tmseeds.com/germination-guide/index.html.

Summer may have gone by for you in an instant this year. It sure did for me. But harvesting and saving the seed from some of my favorite vegetables and flowers gives me the satisfaction of knowing that, if I can wait out the winter, I'll have a head start on next year's garden.

Active in the horticultural industry since 1994, Glen O. Seibert is a former editor for Garden Gate magazine and now works as a writer, landscape designer and self-professed “gardening media mogul.”