If you love butterflies, don’t plant butterfly bush!
Rip it out, if you have some. Butterfly bush (Buddleja davidii) helps exterminate butterfly populations, and is detrimental to songbird populations, too. Native to China, it is not edible by the caterpillars of our butterflies. Sure, it attracts them with its nectar, but the butterflies lay their eggs on the plant and their offspring starve to death.
Songbirds, even the vegetarian species, feed their young almost entirely on caterpillars. It takes at least 2,000 caterpillars to raise a nest of cardinals. Doves are the only exception.
Plant milkweed! Common milkweed, Asclepias syriaca, a native plant that produces beautiful fragrant flowers will attract many butterflies. There are also many other native species of milkweed that are equally good. If you care about butterflies and songbirds, a good rule is to plant native species. You would be amazed at how many beautiful garden plants are native to our area.