What’s causing bare spots in my lawn?

Q. Part of our front and east side lawn has large bare spots. What is the cause of these bare spots? Have grubs or the large maple tree in front caused this?

A. There can be many reasons for bare spots in lawns, including grubs and excessive shade or competition from a nearby tree.

Generally, a grub’s habitat is under grass that is in full sun, not around trees. The easiest way to look for grubs is to dig up areas of lawn on the fringe of the bare spots. The grubs will be 2-3 inches below the surface and look like little shrimp. Typically, you will see 5-10 in a square foot. You will not miss them if they are the problem.

If you don’t see grubs, and the maple tree is a Norway Maple, the problem is the dominant nature of the tree. The shade and roots from the tree will overcome the grass every time.

• Annual seeding with a shade grass mix may improve the situation, but only for a short time – usually not even a full season.
• You could replace the grass with a ground cover like Pachysandra, which seems to compete well with Norway Maple.
• Spreading a layer of organic mulch around the tree is another option (to replace the grass).
• If you really think you need or want grass in that particular spot, you could remove the tree. 

In the case of the Norway Maple versus grass battle, I am afraid we see this as an ongoing problem, and we face few options.