Q: My have annual bluegrass in my fescue lawn. I know this weed can be prevented by applying a pre-emergent in fall. The problem with this is that I have to overseed fescue in September to correct dead spots. A landscaping guru on national TV said there is a pre-emergent that will prevent crabgrass while still allowing fescue seeding to be done. What is it?

A: The guru was referring to the pre-emergent chemical siduron. It has recently become available as in Scotts Starter Fertilizer plus Crabgrass Preventer. Siduron works as described on crabgrass but it does NOT control annual bluegrass. I’ve collected the thoughts of experts on fall bluegrass control at Annual Bluegrass – Control in Fall-planted Fescue.