All this work and planning is unnecessary with flowers that self-sow, replanting themselves from seed every year. Count among self-sowers some annual, biennial and perennial flowers.
NO PLANTING NEEDED
One favorite self-sowing flower, twinkling up at you each spring with its starry, white-eyed, blue flowers, is forget-me-not. Nurture and plant it once, and a new crop of seedlings appears each spring — reliably and without your helping hand.
Shirley poppies are another self-sower, unfolding papery, cardinal red flowers each spring.
Also reliably coming back each year, all by themselves from self-sown seeds, are calendulas, also known as pot marigolds. Well into fall, they brighten the garden with their orange and yellow flowers.
Want more? There's ferny-foliaged cosmos as well as that old-fashioned flower, bush balsam, a relative of impatiens with upright stems along which open red, pink or white blossoms that resemble miniature roses. Even impatiens itself sometimes is a self-sower.
These self-sowing flowers do need a little care beyond their first planting. You can't tell self-sowing flowers just where to grow; forget-me-nots, for instance, might decide to inch their way into a vegetable garden that's close enough to their original home. Calendulas may need help because they often self-sow too thickly.
Your job in caring for self-sowing flowers is, in late spring, to pull some out where they are overcrowded, and to pull all out where they are not wanted.
KEEP AN EYE ON SELF-SOWERS
You may sense that self-sowing flowers walk a fine line between being garden plants and weeds. True.
Foxglove is a self-sowing biennial that may be too freely self-sowing in your garden, so much so that you have to "weed" it out completely. Or not.
Nicotiana is also very free in this sense. Then again, you may want to keep it around anyway so as not to miss out on its irresistible nocturnal fragrance.
Fright is not a word usually uttered in the same breath as such charming, dainty flowers as chamomile and Johnny-jump-up. But these flowers can be frighteningly prolific in an environment that is too congenial. Chamomile not only self-sows but also spreads by runners. Johnny-jump-ups can be charming or, because they also produce underground seeds from flowers that don't even open, a little alarming.
FRIEND OR FOE?
Whether a self-sowing flower becomes a friend or a weed varies from garden to garden. Not only does the site itself matter, but also how you garden: whether you turn the soil, whether you mulch and, of course, just how diligent you are about weeding.
With the right site and gardener, both chamomile and Johnny-jump-up are wonderful garden plants.
When you decide to plant a self-sowing flower, be aware that offspring will not necessarily be identical to each other or replicas of their parent — definitely not if you begin with hybrids. But the resulting variability and reversion to wilder forms lend a relaxed, friendly air to a garden. Moreso because self-sown flowers never line themselves up like soldiers.