An 8-inch zinnia in full bloom is a workhorse annual that carries color from July through frost without complaint. Flowers range from pompom doubles to dahlialike forms in reds, pinks, oranges, yellows, and whites, depending on variety.

Full sun and decent soil with regular water keep zinnias flowering hard. Deadhead spent blooms to push more flowers, and they'll reward you with armfuls for cutting all season.