Some crops are self-seeding. With a bit of light management each generation can be coaxed into providing seeds season after season. One of the characteristics of a truly sustainable garden is that it produces at least some of its own seed. This is most often done when gardeners select, harvest and store seeds until the proper time for planting the following year. But some self-seeding crops produce seeds so readily that as long as you give them time to flower and mature, and set seed, you will always have free plants growing in your garden.

You can simply let the seeds fall where they are, or toss pieces of the seed heads into the corners of your garden, or whichever area you want them in — no harvesting, storing or replanting required. With most self-seeding vegetables, herbs and annual flowers, you’ll just need to learn to recognize the seedlings so you don’t hoe them down. Should seedlings require relocation, you can simply lift and move them — after all, they are sturdy field-grown seedlings.

In addition to getting all the free garden plants you need (and some to share with family and friends), nurturing self-seeders is also a great way to provide a diversity of flowers that supply pollen and nectar for beneficial insects. Self-seeding flowers, herbs and vegetables that show up in early spring include arugula, calendula, chamomile, cilantro, dill, breadseed poppies and brilliant red orach (mountain spinach). Nasturtiums, amaranth, New Zealand spinach, and even basil or zinnias appear later, after the soil has warmed.

Starting a new colony of any of these annuals is usually a simple matter of lopping off armloads of brittle, seedbearing stems in the fall, and dumping them where you want the plants to appear the next season. It’s that easy. Most of the seedlings will appear in the first year after you let seed-bearing plants drop their seeds, with lower numbers popping up in subsequent seasons.

Working with reseeding, or self-sowing, crops saves time and trouble and often gives excellent results, but a few special techniques and precautions are in order. Some plants that self-sow too freely — especially perennials such as garlic chives or horseradish — will cross the line into weediness if not handled with care.

Spring Seeds for Fall Crops

The first group of plants to try as self-sown crops — both because they’re the easiest and they’ll be ready the same year — are those that tend to bolt in late spring. If allowed to bloom and set seed, dill, radishes, arugula, cilantro, broccoli raab, turnips and any kind of mustard will produce ripe seeds in time for fall reseeding in most climates. Lettuce will take a little longer, but often gives good results in Zone 5 or warmer.

One way to encourage self-seeders is to select vigorous plants from a larger planting, and let these plants grow unharvested until they bloom and produce seeds. This will work well enough, but it’s often bothersome to have one lone turnip holding up the renovation of a planting bed. To get around this problem, use a Noah’s ark approach: Set aside a bed or row and transplant pairs of plants being grown for seed into the ark bed. As the weeks pass, weed, water and stake up seed-bearing branches to keep them clean, but don’t pick from the “seed ark” bed.

When seed pods dry and begin to shatter, gather and store some of the seeds as usual for replanting next year (just in case the reseeding effort isn’t successful). Shake and crumble the rest where you want the next crop to grow, and pat the soil to get good contact between soil and seeds.

Or, simply lay well-broken seed-bearing branches over a prepared bed and walk over them. This will shatter seed pods and push seeds into the soil at the same time, and the stem pieces will serve as a starter mulch. With fast-sprouting crops such as arugula, a drenching rain or good hand-watering is all it will take to bring on a lovely fall crop.

Many of the seeds that hit the ground will rot or be eaten, but hundreds will survive winter and sprout in spring. Their strength is in their numbers. When you sow a bed of cilantro, for example, you might plant between 25 and 50 seeds. But when nature is in charge, a single plant may shower your garden with a thousand fresh, plump seeds. Cilantro seedlings are easy to dig and move, and they make well-behaved “weeds.”

Managing Annual Self-Seeding Crops

Many annual crops will reseed themselves if you leave them in the garden long enough for the seeds to mature and the fruit to decompose. Annual veggies that frequently reseed and provide volunteer seedlings include winter squash and pumpkins, tomatoes and tomatillos, watermelon, and New Zealand spinach.

There are two issues to consider when managing this band of garden volunteers: disease and location. The two most serious diseases of potato and tomato — early and late blights — can actually be perpetrated by encouraging disease-carrying volunteer plants. Especially if you saw late blight in your garden the previous season, you should seriously consider breaking the disease cycle by digging up and composting potatoes that sprout from the previous year’s patch, along with all volunteer tomatoes and tomatillos that appear early in the season.

However, sometimes in late summer, I do adopt tomato volunteers that have a potato-type leaf, because I know what they are. ‘Brandywine’ is the only potatoleaf tomato variety I’ve grown in the last five years, so any potatoleaf volunteers are highly likely to be ‘Brandywines.’

You also can recruit healthy volunteer tomatillos based on their distinctive leaf shapes. I locate these foster children around the garden as single plants, spaced far from my main ripening crop. Or you can consider moving volunteers to containers and growing them outside of your garden as a disease safety precaution. With late blight, it’s better to be safe than sorry.

Volunteer Veggies

If you’re growing open-pollinated (OP) varieties, it can be fun to let volunteer winter squash, pumpkins, gourds and watermelons ramble along the garden’s edge, or scramble over wire fencing. (Remember that seeds from hybrid varieties usually won’t grow “true to type.”)

Check the plants weekly for signs of powdery mildew disease, which is a common problem with older open-pollinated varieties. Squash or pumpkin plants that show signs of powdery mildew before the fruits have set should be pulled out, but don’t worry if the white mildew patches appear later on when the fruits are almost ripe.

The plants will still bear a good crop. If volunteer winter squash are always a part of your garden’s landscape because so many seeds survive in your compost, you can introduce powdery mildew resistance to your local population by growing OP varieties which are resistant to powdery mildew, such as ‘Honey Nut’ butternut and ‘Cornell’s Bush Delicata.’

34 Easy Self-Seeders

Herbs: basil, chamomile, cilantro, cutting celery, dill, parsley

Vegetables: amaranth, arugula, beets, broccoli raab, carrots, collards, kale, lettuce, orach, mustards, New Zealand spinach, parsnips, pumpkin, radish, rutabaga, tomatillo, tomato, turnips, winter squash

Flowers: bachelor button, calendula, celosia, cosmos, nasturtiums, poppies, sunflowers, sweet alyssum, viola

Managing Self-Seeders

• In the fall, toss seed heads wherever you want seeds to germinate. Or, next spring, transplant volunteers to the spots where you want them to grow.
• Be sure not to hoe “weeds” too early in the spring.
• Learn to identify the self-seeder seedlings.

Source: www.motherearthnews.com