Q:  I have a lot of Creeping Charlie weeds in my lawn.  When is the best time to apply a weed killer?

A: Mid- to late autumn is an excellent time to apply post-emergent herbicides to control invasive weeds in turf such as Creeping Charlie (Glechoma hederacea), White Clover (Trifolium repens), and Violets (Viola).  Chemicals applied to weeds at this time of year are more effective because the plants are actively translocating nutrients downward to the plants’ root systems to prepare for winter.  For best results, don’t mow right before or right after application to allow more leaf surface to absorb chemicals.  Apply only when no rain is expected for approximately 24 hours.  Also, it is important to apply weed killer when the air is still to avoid the possibility of chemical drift which can damage desirable plants.  If possible, spot treat weeds instead of applying herbicides to the entire lawn.  Please contact Plant Information Service for chemical recommendations.