Last year was my first spring/summer in my new house. Not ever owning a home before, I don’t know what to do when it comes to my lawn. Over the summer, a lot of crab grass took route. We applied a fertilizer in the fall. Right now, at the end of March, the snow is gone, the grass has not started to green yet, but I can just see all the dead crab grass and the lawn looks horrible. I know that I should wait to apply the crab grass preventer until when? Late April? Early May? But, what about the dead patches of crab grass that are there now? Should we plant some more grass seed? Will the new grass grow “over” the dead patches of crab grass from last season? If we should plant new grass seed, when should that be done? Thanks!
Crabgrass, unlike most lawn weeds, grows from seed that the mother plant produced the previous summer. The mother plant dies completely over the winter never to be seen again. In early spring the seed germinate and start to grow. Crabgrass preventer is an agent that dissolves and forms a coating on the surface of the soil. ANY seeds that try to sprout and push a root through that barrier are killed. The best way to time your crabgrass preventer application is to keep an eye on a forsythia bush that is growing in your yard or neighborhood. The best time to put your crabgrass preventer down is right as the flowers are falling off the bright yeallow forsythias (right as thelilacs are just opening). It is a convenient coincidence that crabgrass seeds germinate at the same time that forsythias are finishing flowering. Spring weather can be fickle but, if you use the forsythia as your clock, your crabgrass preventer will always go on at the right time. Remember that crabgrass preventer forms a thin film on the surface of the soil so make sure that all your raking is done before you apply crabgrass preventer. If you rake afterward, you will scratch up the barrier and crabgrass will be able to grow.