Easy Steps for Saving Seeds From Your Garden
Question: I would like to collect and store seeds from my plants. How do I go about doing this? Would seeds left over from last year still sprout?
J.D., Anaheim
Answer: As summer is winding down, now is the perfect time to save seeds from flowering plants. Both hybrids and open pollinated varieties will produce seed. It is important to remember, however, that hybrid plants have several different parents and will not produce true to type.
In other words, the seeds you harvest from them won’t reproduce the same plant. With this in mind, you may wish to start with seed collection from nonhybrid plants.
As plants start to bloom, you may want to consider staking up any heavy flower stalks. After the flowers drop, the seeds start to form, swell and then dry. The goal is to let the seed capsules dry, but collect them before they drop to the ground and start another plant cycle.
It is important to observe the entire life cycle of plants to help you ascertain when their seeds might be ripe. Seed heads tend to mature from the bottom to the top or from the outer edges to the center. Below are some guidelines to aid you in harvesting and storing your seeds.
Harvesting
* Watch for drying, brown flower stalks and seed pods that have turned from green or yellowish brown to brown, gray or black. Most herbs, for example, turn black or brown when ready to harvest.
* A good way to check for seed maturity is to lightly tap on the dry flower stalk. Seeds that rattle or are dislodged are ready for harvest.
* Birds also tend to begin eating the seed heads once they are nearly ready to harvest (although some may eat green seeds).
* Small seeds or those contained in pods are a bit more difficult to assess. Rub your thumb on pods in various stages of maturity. Green ones will seem a bit waxy and mature ones will have a papery texture.
* Plants with explosive seed capsules such as California poppies can be picked just shy of complete ripeness and will finish the ripening process in a paper bag. The ripe seed capsules of many annuals will open slightly without spilling any seed, making them very easy to collect.
It is important that the seeds are dry, as moist seeds will mold. To assure that all plant parts are dry, harvest seeds late in the day.
* Only collect seeds that separate easily from the plant. If they do not separate easily, you may inadvertently injure the seed or it may not be fully developed.
* Harvest dry seed every couple of days by bending seed stalks into a paper bag and shaking off the dry seeds. You can even cut the entire seed head when some seeds at the bottom have begun to drop and most seeds have changed color. Hang the stalks upside down, out of direct sunlight, over a basket to dry.
* When you shake seeds off of dry plants you will get a mixture of seeds, soil and crumbled leaves. Put seeds in a strainer and shake gently to remove debris.
* Never dry seeds in direct sunlight. To assure that they are completely dry, spread the seed out in trays in a warm dry place. This process will weed out a variety of little pests such as caterpillars and weevils.
Storage
* The optimum storage temperature for seeds is from 35 to 65 degrees Fahrenheit in an area with low humidity. The refrigerator is ideal if you have the space. Store the seed in sealed containers such as baby food jars or medium-sized jars if you are storing several different seed packets.
* Seeds will live longer and germinate faster if kept dry. To keep moisture away from your seeds, add a homemade desiccant of two tablespoons of dried skim milk powder wrapped in four layers of facial tissue, tied with a rubber band. Place this little bundle in the bottom of the jar and it will absorb moisture.
Be sure to replace the powdered milk pouch every six months. Other desiccants such as silica gel, found at camera stores, can also be used.
* Check your seeds periodically for mold and insect damage. If the seeds change to a black sooty color, a black downy dust appears when they are sprinkled out onto a sheet of white paper, or they clump together when the jar is slowly turned, mold may be present. If so, discard the seed.
If you find dust at the bottom of the container, insects may be present. If you suspect an infestation, freezing the seed for a couple of days will kill the insects.
Seed shelf life is partly dependent on storage conditions, as well as seed variety. Charles Ledgerwood of Ledgerwood Seeds in Carlsbad has identified the storage life for the following flower seeds:
* 1 year: Delphinium; lavender; phlox; vinca; viola.
* 2 years: Aster; Clarkia; columbine; coreopsis; dahlia; dimorphotheca; forget-me-not; four o’clock, foxglove; gypsophila; helichrysum; impatiens; nemesia; pansy; platycodon; poppy; scabiosa; schizanthus; verbena, zinnia.
* 3 years: Alyssum; calendula; campanula; candytuft; carnation; centaurea; cosmos; daisy; dianthus; godetia; hollyhock; ipomoea; larkspur; lobelia; lupine; nasturtium; nicotiana; petunia; sweet pea.
* 4 years: Celosia; gaillardia; linum (flax); stock; wallflower.
Some gardeners have found flower seeds of Shasta daisies, calendula, sweet peas, poppies and marigolds to still be viable after five to 10 years.
To ascertain whether your seed is still viable, do a yearly germination test. Place a few seeds between two moist paper towels on a plate and put in a warm place (around 70-75 degrees).
After a week, peel the paper towels apart to see if the seeds are sprouting. Based on the percentage that sprouted, either throw them out or when planting, sow more seeds to adjust for the decreased germination rate.
Have a problem in your yard? University of California Cooperative Extension (UCCE) Master Gardeners are here to help. These trained and certified horticultural volunteers are dedicated to extending research-based, scientifically accurate information to the public about home horticulture and pest management. They are involved with a variety of outreach programs, including the UCCE Master Garden hotline, which provides answers to specific questions. You can reach the hotline at (714) 708-1646 or send e-mail to ucmastergardeners @yahoo.com. Calls and e-mail are picked up daily and are generally returned within two to three days.
