Some oxalis are grown for ornamental purposes, but two, Oxalis stricta (an annual) and O. corniculata (a perennial), are common weeds throughout the yard and in greenhouses. Also called yellow wood sorrel or sourgrass, the perennials grow most commonly in well-maintained areas. The pale-green or purple leaves are divided into three leaflets, like clover leaves. Small, bright-yellow flowers bloom from May to September. Cucumber-shape, light-green seedpods develop from the fading flowers. The seeds germinate throughout the growing season. Plants grow 4 to 12 inches tall.
Oxalis can also be hand-pulled or hoed if it is done before rooting occurs on stems. Follow recommended lawn care practices for a healthy, vigorous lawn. A healthy lawn helps smother the oxalis.