BROOKINGS, S.D. - Fall is the time to control tough perennial broadleaf lawn weeds. Good moisture in most places in August helped contribute to significant fall growth of perennial weeds. Fall is a good time to target weeds such as dandelion, ground ivy, creeping bell flower, field bindweed, and white clover. Ground ivy is also known as creeping charlie and field bindweed is often referred to as creeping jenny.
Results of the SDSU Weed Evaluation Extension Evaluation (WEED) project show fall timing has the best chance for control of dandelions. Active new growth is important for good results. Allow the grass to grow up and delay mowing to get good growth. Spraying can start anytime in September. For the toughest weeds, like ground ivy and creeping bell flower, make a repeat application as soon as the product labels allow, ideally two weeks after spraying.
Fall works best for perennial weeds because the herbicide moves into the root better. If you wait until after a light frost, other plants in the yard are less sensitive to drift. Apply with care and use low pressure and coarse droplets to reduce drift. Do not make applications if it is windy. Most broadleaf lawn products are a mixture of herbicide ingredients and they are available in several product brands. Check label guidelines for mixing and applying instructions.