For maximum effectiveness, the herbicide should be watered-in within two or three days of application. Consult the label for additional information. Timing is everything when it comes to application of a preemergent herbicide. While it is commonly assumed that blooming of forsythia signals the time to apply the herbicide, this assumption does not always ring true. Under normal conditions, in this part of Pennsylvania preemergent herbicides for control of crabgrass should be applied between March 15 and April 15.
Snow mold is a fungal disease that attacks turfgrass.
Signs of this disease are usually noticed in the spring as the snow melts and typically appear as off-color, crusted, matted leaves of turfgrass. Affected areas may range from several inches to several feet across. Fungal bodies, called sclerotia, are responsible for creating patches of snow mold. If there is no snow cover or if snow rests atop frozen soil, gray snow mold is unlikely to occur. While a application of a fungicide may be warranted in unusual cases, gray snow mold can for the most part be successfully controlled with the proper cultural practices.