General guidelines for cool-season grass, LATE spring lawn care:

Examine lawn for signs of insects or diseases. Raise the mower deck and cut grass higher to enhance stress tolerance for warmer weather. Fertilize or compost. Water deeply as necessary. If broadleaf weeds are a problem, apply postemergence broadleaf herbicide. Use a grass catcher on mower to reduce thatch and spreading weed seeds. Edge and trim as needed.