We have a potential client in Northern VA (zone 7) w/ a couple lg. dead spots in his Tall Fescue lawn. Lawn is irrigated via sprinkler system & was plenty moist when I checked it out. There are 2 lg. spots, one in the front about 500 sq. ft. & the other in the back about 300 sq. ft. I noticed a lot of sm., quick moving spiders in his turf & quite a few sm. holes that I believe the spiders inhabit. The rest of the lawn looks great, any ideas why these areas are dying out? Would you recommend top-dressing w/ compost, seeding, & strawing in a few weeks or is there another problem at hand?