Property owners who notice winter damaged areas on their turf grass should consider skipping the application of crabgrass preventer if overseeding or patch seeding of the damaged areas is being considered.  Grass seed will not germinate properly if crabgrass preventer has been applied.  The same ingredient that prevents crabgrass seed from growing will also prevent lawn grass seed from germinating properly.

This means that you will have to skip crabgrass preventer this year, or apply crabgrass preventer very carefully only on healthy areas and not at all on damaged areas where you plan to do seeding of turf grass.  This selective application of crabgrass preventer may be quite difficult to do with accuracy.  I recommend just skipping the crabgrass preventer this year if you plan to do any grass seeding.