Perennial
All zones
Full sun
Average water
Sweet marjoram is a perennial in Zones 4-24, 29-31; elsewhere, it is treated as an annual or grown in containers and moved indoors for winter. Plants reach 1 to 2 feet tall; the tiny gray-green leaves have a sweet, floral scent and a milder flavor than oregano (to which sweet marjoram is closely related). Start this herb from seed or purchased transplants; space plants 6 to 9 inches apart or thin seedlings to this distance.