(You just can't have enough of this plant in your garden.)
My wife is always saying that our gardens are not lush enough. They just don't look as "full" as Mrs. Lydiya's gardens, the Latvian neighbor with a green thumb. "Why do we have all those gaps between the perennials in the flower gardens or all that space between those squash plants in the vegetable garden? You are so stingy with your planting. Buy more, divide more, plant more, fertilize more." Jeez o'Pete. I am the one who is out there swatting deer flies, swallowing gnats, squishing Japanese beetles, and lifting 20,000 year old rocks out of this forlorn clay soil. Do I get no respect at all? If I quit weeding I'll bet the gardens would look lush enough.
But then, I discovered a panacea to my perennial gardening space problems: Rudbeckia. More specifically, I think I have Rudbeckia hirta, or black-eyed susan. Plant a clump of this one and your worries are over. It spreads like crazy from its original patch and it pops up in bare ground from the previous year's seeds. In fact, it is almost a weed once it gets started, although it is a very attractive weed. It makes me feel like I am doing something right in the garden, that Mrs. Lydiya really doesn't know something I don't know, and it makes my wife proud. What a plant!