Yellow Woodsorrel
Broadleaf weed
Yellow woodsorrel (Oxalis stricta) is a low-growing broadleaf weed found across most of the United States in lawns, gardens, greenhouses, and container plants. Gardeners and growers notice it because its clover-like leaves and small yellow flowers blend into turf and beds, and because it spreads quickly and pops up almost anywhere the soil is disturbed.
How to identify it
The leaves look like clover, with three heart-shaped leaflets that fold along the midrib and often close at night or in bright heat. Plants grow as a low, branching mound or sprawl along the ground, typically 4 to 12 inches tall, and stems can root where they touch the soil. Flowers are small and bright yellow with five petals, blooming through much of the growing season. The most telling feature is the seed pod, a slender upright okra-shaped capsule that splits open and flings seeds several feet when touched or ripe.
Where it grows
It thrives in lawns, flower and vegetable beds, cracks in walks, nursery pots, and any disturbed or bare soil in both sun and part shade. It grows from spring through fall and can behave as an annual or short-lived perennial depending on climate and conditions. Yellow woodsorrel spreads mainly by seed, ejecting seeds explosively from its pods and moving readily in potting mix and on tools, and it can also root at the nodes of trailing stems.
Why it is a problem
Its explosive seed dispersal lets a few plants seed an entire bed, greenhouse bench, or lawn in one season, and buried seed can stay viable for years. In gardens and nursery production it competes with young plants for water, nutrients, and space, and it is one of the most common and persistent weeds in container stock. The plant contains oxalic acid, which gives the leaves a sour taste and can be a concern if eaten in large quantities by grazing livestock.
How to manage it
Hand pull or hoe young plants before the flowers form seed pods, since removing them early breaks the seeding cycle that makes this weed so hard to control. Try to lift the whole plant, including the shallow taproot and any rooted stems, and pull when soil is moist so more of the root comes free. In beds, a 2 to 3 inch layer of mulch blocks light and greatly reduces new seedlings, while a dense, well-fed, and properly mowed lawn crowds it out of turf. For containers and greenhouses, start with clean potting mix, keep benches and floors free of stray plants, and remove new seedlings promptly so they never reach the pod stage.
Commonly confused with
It is most often confused with true clovers and with black medic, but those have rounder or oval leaflets and different flowers, and neither has the sour taste or the pointed, seed-flinging pods of woodsorrel. It also closely resembles creeping woodsorrel (Oxalis corniculata), which tends to sprawl and root along the ground more and often has reddish or purple-tinged leaves.
General guidance for US lawns and gardens, focused on prevention and non-chemical control. For a confirmed identification and options specific to your area, contact your local Cooperative Extension office. Page updated Aug 4, 2026.