Don’t confuse this weed with clover – it’s MUCH smaller and has tiny yellow flowers. A relative of woodsorrel, oxalis is a woody herbaceous plant – unlike clover, which is a legume. Oxalis has a nasty habit: it has exploding seed heads! As each tiny yellow flower dies and dries up, a seed bud forms, and a powerful spring mechanism grows inside the bud. When the trap is sprung (usually by a passing lawn mower or a gust of wind), multiple seeds are thrown out up to 18″ away from the plant. The seeds germinate, and make new oxalis plants.

Control: Oxalis is easily killed using Ortho Weed-B-Gon or Bayer Advanced All-in-One Lawn Weed Killer, but you will need to spray several times to get the newly sprouted plants, as the seeds are unaffected by the weed killer. These chemicals will not damage the lawn grasses when used properly. As with all broad-leaved weeds, spray in between mowing and do not water for several days.