It's illegal to buy, sell or plant purple loosestrife, and It's banned in nurseries and farmer's markets.
The native perennial fireweed produces spikes of magenta flowers July through September.
Asters are the stars of our September gardens, and indeed the word aster means ‘star'.
There are some perennials that provide an added bonus of foliage that changes color in the fall.
Cool fall days give gardeners the incentive to divide perennials, so that new starts can be established before the winter.
"Honesty" has purple flowers followed by seedpods that are shaped like coins. Hence the plant's common name of "Money Plant."