If you want to save time and money in the garden, and create an ongoing crop of some favorite plants, it's as simple as saving seeds from your own plants, or letting some plants "naturalize."

Seed-saving is a tradition that also preserves heirloom varieties, many of which are vanishing from catalogs. Naturalizing, which can be defined as the practice of letting a plant spread through your garden on its own, is an accidental technique that can be used to advantage if done purposefully.

Save your faves

If you haven't yet cleaned up the summer vegetable garden, you can begin your seed-saving experiment right away. You also can start now with winter vegetables that have just been planted. The summer crop will naturally have a few stragglers — the carrots or beets still in the ground, or the lettuce that didn't get eaten. Those might be the start of your seed plants. Individual starts from your winter vegetables, like spinach, can be designated as seed plants while they're growing.

There are a few considerations to successful seed-saving:

Do you have open-pollinated or hybrid seeds? Open-pollinated seeds will grow true to their parent plant, while hybrid seeds will not.

Both types of seeds have value: While open-pollinated seeds tend to be cheaper to buy, hybrids may have been bred for better yield or disease resistance. For seed-saving, open-pollinated is the choice.

Do you have a good specimen? It's not ideal to save seeds from the weakest runt in the row. Designate the healthiest one as your seed plant — something that can be done now with your winter vegetables. But using your summer leftovers may give you a chance to try your hand at the technique. Don't save seeds from a diseased plant.

Did your plant possibly cross-pollinate? Some plants need pollination from other flowers, and the seeds of those plants could result in a different cultivar. If you're growing multiple varieties, isolate your designated seed plant.

Is the plant an annual or biennial? Annual vegetable crops such as tomatoes and peppers will have seeds to harvest and dry this year. Biennial plants such as carrots or lettuce will need another year to produce seeds. You'll see an annual "going to seed," but you'll want to plan for the biennial, because it will take extra care.

Seed-saving has become a political act as well. Over the years, many heirloom varieties have been lost as companies have focused on selling hybrid seed. Iowa-based Seed Savers Exchange (which also has a useful book on seed-saving techniques) and Port Townsend-based Seed Alliance can be good resources. They also offer programs worthy of support for those who want to prevent the demise of more seed varieties.

Let nature do its thing

Do drying, bagging and storing sound like too much work? Why not just let seeds drop where they are and sprout? This merges gardening practices with nature's own cycle. Rather than harvesting seeds, storing and replanting, let them replant themselves in a continuous cycle.

This technique is not advisable for all food crops, but is possible for some. Hardy greens such as arugula and kale will readily drop and sprout, moving around the garden from season to season. It's only up to the gardener to thin the starts or remove them from areas where other plants are desired.

Conversely, letting tomatoes self-sow would not be healthy (even if it were possible in our climate), because soil-borne diseases such as late blight mean it's wise to not continually grow tomatoes in the same location.

Whether you're saving seeds or just letting them drop, making an attempt to close the loop from planting to replanting is another way to cut down on seed costs, enjoy your favorite varieties year after year and follow through on efforts to be a practical gardener.

Bill Thorness is a freelance garden writer in Seattle: bill@thorness.com.