Now is the time to think about spring lawn care. First, rake up the dead grass under the growing grass. This is called thatch and if it is ½ thick or greater, you want to remove it to allow better water and air penetration to the soil. Thatch is usually caused by mowing too tall of grass blades several times during the summer.
If you have small areas of dead grass due to foot traffic, dogs, or heavy snow, you can overseed or dig up those areas and replant them. Fall is the preferred time to redo large areas of the lawn.
Fertilize with lawn fertilizer, especially if not done in the fall. A good time to apply is before rain or water in. Applications are made from May to early June. If you keep the clippings for mulch, wait till after two mowings before using so there is no herbicide residue left in the grass blades.
If you use a weed and feed type of fertilizer, wait till you see weed growth then fertilize. Always follow the rates and directions on the bag. You will have to go around later in the season and spot-treat those pesty weeks with a liquid fertilizer with a hand sprayer. In using a weed and feed fertilizer do not water and make sure there are at least 2 days without rain so the herbicide is not washed off. When applying, do it early in the morning when there is a due on the grass blades so the granules stick or water the lawn first.
The main question is always when to apply a preemergent crabgrass control. Crabgrass germinates when the soil temperature gets to 55 degrees. So, it is best to apply the crabgrass control granules before this. Crabgrass control usually lasts 4 weeks in the soil unless it rains heavily then much less time. The preemergent herbicide kills the crabgrass seeds as they germinate, so it does need to be watered down into the soil. This can usually be timed for when the lilac blossoms swell and when they start to open. Some people apply two applications four weeks apart if their lawns have been overtaken with crabgrass.