Black-Eyed Susan

Black-eyed Susan is not quite what most gardeners think it is. The common roadside form, Rudbeckia hirta, is technically a short-lived perennial, but in practice it behaves more like a biennial or an enthusiastic annual — it blooms hard for a year or two, sets a prodigious amount of seed, and then quietly disappears. The confusion comes from the fact that seedlings tend to fill in where the parent plants were, so the patch persists even as individual plants come and go. A gardener who expects the same clump to return for a decade will be disappointed.

The upside of this habit is that once you have black-eyed Susans established, they tend to maintain themselves. The seed heads ripen in late summer and fall, goldfinches strip them down, and the seeds that drop germinate the following spring. If you deadhead religiously, you get a tidier garden and fewer seedlings; if you leave the seed heads standing through winter, you get birds and a self-renewing bed. Most gardeners find a middle ground — cutting back half the plants and leaving the other half to reseed.

Drainage matters more than fertility. Black-eyed Susan tolerates poor, lean soil without complaint; what it cannot tolerate is sitting in wet clay through a damp winter. Plants that thrive in their first summer may rot out over the winter if the soil stays soggy. A raised bed or a sloped site tends to give better long-term results than a flat, heavy bed that holds water. Fertile soil, oddly, can work against you — plants fed too much nitrogen grow tall and floppy and need staking, which defeats the whole low-maintenance premise.

The flowers open in July and keep coming until frost if you cut them regularly. Each bloom lasts about a week in a vase, and the chocolate-brown cone in the center is what gives the plant its name. Pollinators — bees, butterflies, beetles — mob the flowers in late summer when not much else is blooming. The foliage is coarse and hairy; you won't want to brush against it in shorts.

If your patch starts to thin out after a few years, the usual cause is poor drainage or competition from aggressive perennials. Black-eyed Susan tends to get shouldered out by stronger-rooted neighbors unless you give it space. A light scattering of seed in fall, pressed into bare soil, usually restocks the bed without much fuss. The species tends to be more vigorous and longer-lived than some of the fancy cultivars, which can be shorter-lived still and less inclined to self-sow true to type.