|when do you treat for grubs|
|First of all, be sure that grubs are present (that the problem is not chinchbugs or some other pest) and the population is large enough to be causing damage to the lawn. If not, there is no need to treat.
You could apply beneficial nematodes in spring or fall. These are available from garden centers and from mail order sources such as Gardens Alive.
For help in identifying the pest in your lawn you might consult with your local county extension. They may also have control recommendations based on knowing specifically which pest it is.