Pre-emergent for lawns and beds prevents future annual grasses and broadleaf weeds from germinating during the growing season. These products work best when applied in advance, so the timing of the application is important. In Virginia, generally the best time to apply these products is in February and early March. Don’t wait for the Forsythia to bloom, as this may be too late.
Examples of annual weeds in lawns controlled by pre-emergent herbicides include crab grass, goose grass as well as a host of broadleaves such as spurge, lespedeza and oxalis. It is important to water them after each application within 7-10 days, as they break down in sunlight.
For annual weed control in flower beds, these products are best applied in late February or early March in conjunction with mulching. Plan on applying the pre-emergent herbicide prior to mulching, as this helps it last even longer. Also, a non-selective product should be utilized to clean up existing winter annual weeds in the beds. Please don’t pull weeds in flower beds after an application of a pre-emergent herbicide, as this breaks the barrier.
Measuring your lawn or bed size is critical to the success of these applications. If you need landscape assistance this spring, please do not hesitate to contact Virginia Green, the local experts. Our staff is glad to assist you in making your landscape the best on the street.