Many Susans are worth planting in flower gardens

What gave Susan a black eye? Her central florets, that's what.

Black-eyed Susan flowers are actually made up of many small florets, two kinds. The florets in the center of each flower -- the eye -- lack petals and are dark. Hence, the black eye.

Florets around the outside edge of the eye each have one petal, large and orange yellow. These petals point outward around the black eye like a sunburst.

Over much of the country, black-eyed Susans have spread open their petals in sunny fields, laughing off summer heat and unfazed by dry spells. This flower's not finicky about soil either, thriving almost everywhere it can grab a half a day or more of sun.

With such qualities, it's no wonder that black-eyed Susans have been moved into flower gardens, usually as a short-lived perennial. Sow seeds in early spring to enjoy blossoms beginning that same season. Sow seeds now and enjoy blossoms beginning next year.

Despite individual plants being short-lived, there's no need to grow new plants every year or two, because the plants reseed themselves naturally. To collect seeds yourself from wild plants, cut off fading flower heads, then let seeds finish ripening in an open paper bag in an airy, warm room. Whether you sow the seeds this summer or next spring, give them warm soil, at least 70 degrees, in which to germinate.

Gloriosa daisies are a botanical form of black-eyed Susan often grown in gardens. With double the usual number of chromosomes, gloriosa daisies have large flower heads, six inches or more across, and sometimes extra rows of petals.

If you like black-eyed Susans for cutting, grow the variety during Indian summer. The flower heads are up to eight inches across, but best is how long the flowers last once cut.

Surprisingly, they look better after a couple of days in the vase than when first cut, then keep looking perky for about 10 days.

Goldsturm is another popular garden variety of black-eyed Susan, actually a different species from the roadside Susans and a bit more demanding of water to put on its best show. Give Goldsturm good conditions, though, and the two-foot high plants will be smothered in three- to four-inch deep yellow blossoms -- with black eyes, of course.

Yet another species, sweet black-eyed Susan, is very drought-tolerant and blooms in late summer. The biggest difference between this black-eyed Susan and the others is plant height: Sweet black-eyed susan flowers perch prominently atop five-foot stalks.