Question
I live in southeast Wisconsin. A local lawn care company applied pre-emergent crabgrass control along with fertilizer this week. There were still a lot of dead leaves on a large area. Was it a waste to fertilize this area? When should dethatching or aeration be done? Should have have been done first?

Answer
Crabgrass pre-emergent needs to get down to the soil. If there was a thick mat of leaves in a section, then that section did not get a good application. It's as simple as that. You should call the company and tell them to re-apply to that area. The technicians should have known better.

Dethatching: Is there a thatch problem? If not, then you don't need to do this. All too often, I see landscapers ripping the daylights out of a perfectly healthy lawn that doesn't need anything of the sort. It's overkill and it will usually do more harm than good. If you lived down south and had to deal with the absurdly aggressive grass species down there, it might be a different story. Up north, you don't need to dethatch as a regular thing.

Aeration: I prefer to aerate in September.

Good luck with the season Kim.

Sincerely,
C.J. Brown
www.TheLawnCoach.com