Buttonweed (Diodia) is native to North America and Africa and has many different species, but we usually just see 2 kinds in our service area– annual common buttonweed (diodia teres) and Virginia buttonweed (Diodia virginiana). It is the latter we are concerned with, since it’s a warm-season perennial and can be a nuisance in lawns, pastures, and some crops.
Virginia buttonweed produces tiny, star-shaped white flowers during the summer, with four petals – this weed is readily identifiable by the flowers. Its leaves are long and leathery, sometimes purplish and frequently mottled yellow with a fungus that seems to plague it. It reproduces by seed, an extensive root system, and stem parts. Its root system includes underground rhizomes (like bermudagrass,) which allow it to spread quickly. The seeds float, so rain easily disburses them from your neighbor’s lawn to yours.
Originally found in the southeast, buttonweed has spread farther west, usually in potted plants. Although it thrives in moist, wet areas, it can also survive drought.
Control: We control buttonweed with a post-emergent in our weed control applications. There is no pre-emergent for buttonweed. We can also spot spray them, but spot-spraying usually takes 2 sequential treatments and can yellow surrounding turf (which will recover with mowing and watering.)
Some recommend hand-pulling it when you notice it, being careful to get as much of the root as you can.
Frequent mowing and good fertilization is usually always the best way to help control weeds. However, buttonweed grows and spreads so low to the ground that frequent mowing, even on the lowest setting, sometimes doesn’t reduce the possibility of the plant reseeding, and doesn’t stop it from spreading.
Virginia Tech has some good, identifying pictures of virginia buttonweed on their website.
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Wild Violets