Pretty perennial may boost your immune system.

Even if coneflowers, otherwise known as Echinacea, weren’t famed around the world as healthful tonic, they’d be popular as garden plants. The tough perennials will form clumps of foliage over time, producing ever more flower stems to enchant the eye. And although you might be interested in making your own Echinacea tea from the leaves and flowers, you should certainly leave blooms for the bees and butterflies.