Question: My lawn doesn’t look good. I fertilize and water, but it doesn’t seem to help. The grass is sparse and pale, and a brown patch has developed where the grass seems to have died off. Is it thatch? Should I treat it for grubs? What am I doing wrong?

Answer: It could be either grubs or thatch, but before any treatment is applied, you need to investigate. If the problem is grubs, you will find them munching on the grass roots, so turn over a couple of shovels of sod and count the number of grubs you see. If there are only one or two, the problem is not grubs. If you find a lot of them — a dozen or so — in a square-foot area, treatment of a grub killing agent is probably necessary.

If your lawn is receiving adequate sunlight, and the brown patch is not a favourite urinating spot for your dog, it sounds as though your lawn may be suffering from compaction, possibly too much nitrogen in the spring and poor drainage. Our soils contain a lot of clay and often do not provide optimum drainage. Do not overwater; an inch of moisture per week is all grass needs, and if you are working with heavy clay, it might be better to water lightly, to a depth of an inch or two, rather than providing the needed inch of precipitation all at once.

It is difficult to diagnose lawn problems without knowing what came before. Winter kill, buried objects, hot spots such as engine exhaust or hot liquids can damage turf. Grass can wear out and die from overuse, such as along paths or under swings. If the grass crown was not removed, the area should recover given proper care.

This week’s answer comes from Joyce Kohley, University of Illinois master gardener, Winnebago County.

Rockford (Ill.) Register Star