Weed group: Summer annual
Characteristics: Reproduces and spreads by seed. It’s leaves will close in the heat of the day. Small yellow flowers with heart shaped leaves. The roots are long and slender with rhyzones. Grows vigorously in weak grass. Oxalis is very common not only in lawns, but flower beds and green houses. It often accompanies the new plant that you just purchased.
Control:
- Cultural: Loves fertile warm moist soils as well as shade. Takes advantage of thin bare areas in the lawn. As the seed pods begin to dry out, they will end up pressure popping open and spreading the seeds.
- Natural: DO NOT scalp your lawn in the spring. If seeds cannot contact the ground nor get sun light they will not geminate. Very easy to hand pull. Plus, if you do not get the entire root, it will not grow back.
- Chemical: Pre-emergent herbicides are effective prior to the seeds germinating in the spring. Little success with post-emergent herbicides. Prevent spring weeds by NOT scalping your lawn in the spring. If seeds cannot contact the ground nor get sun light they will not geminate. The best weed control is a healthy managed lawn.