Self-Seeding Plants

With plants like Melampodium, a self-sowing annual, and the herbaceous perennial tuber rose (figure A), Hoffman creates cultivated garden spaces in a natural, easy-to-care-for setting. Self-seeders are so easy to care for because they virtually grow themselves. For example, the California poppy (figure B) and the ever-popular cosmos (figure C) are both annuals, which die after a season after their single season of bloom. However, Hoffman recommends letting Mother Nature use wind and rain to plant their seeds for you. The plants may look a bit scraggly as the seed head dries out (figure D), but the results are well worth it.

There are several ways to collect seeds. One method is to gently dislodge the seeds from the seed head and store them in a plastic container. You can also sweep up any disconnected seeds with a hand broom and dustpan. Another method called deadheading is as simple as shearing off the spent flowers with pruning shears. If you have a large area to cover, you can even use the lawn mower to cut an area of flowers. Then either dry the clippings and store them in a cool, dry place, or spread the clippings directly on the areas that you want to naturalize.

Because black plastic draws the sun's heat into the ground to destroy the plants' roots, it's most effective to lay it down during the hottest months of the year. Three to four months after applying the black plastic, the plants underneath should be gone.

Hoffman advises to avoid adding any nutrients such as compost or fertilizer to your soil to maintain as natural a state as possible. "Wildflowers like an area of low fertility and full sun." For example, Hoffman planted verbena in his garden and treated the area with fertilizer and compost, meticulously watering the space to encourage growth. However, the verbena would not grow there, but to Hoffman's surprise, it hopped out of the treated area and grew vigorously in a nearby area with more natural soil conditions. The moral of this story is wildflowers actually prefer no extra water, fertilizer or compost.

During the fall, you can let the rain water your seeds for you. Most self-seeders should sprout. "In an area that has several self-sowing plants, use a lightweight compost as mulch," says James. "Heavier mulches such as bark chips can hinder the seeds from reaching the ground. And if they can't reach the ground, how are they ever going to grow?"

If you still need another reason to encourage a garden that replants itself year after year, Hoffman says self-seeders are also home to lots of beneficial insects, such as hoverflies, lacewings and ladybugs, all of which enjoy the pollen and nectar from the flowers. By hosting beneficial bugs in your garden, you will help keep the all-important environmental balance.