You don’t always have to kill chinch bugs

Q: My St. Augustine grass has a problem. Large areas are drying out, but water does not help. Do you think I am going to need to replace the brown areas? — Joao Geraldini, Conroe, Texas

A: I think you have chinch bugs. You may not need to replace the grass at all. Several years ago, I had a gorgeous St. Augustine lawn. St. Augustine is not a common lawn grass in metro Atlanta because it’s not very cold-hardy. I selected St. Augustine grass from a house in Candler Park, which had St. Augustine grass for 20 years. I theorized that the 20-year-old St. Augustine grass had already survived several cold winters, and the susceptible grass was gone. I planted the runners at my house in Decatur where they prospered.

Despite not being cold-hardy, St. Augustine grass is very shade-tolerant, and shade is what I had. A large crape myrtle was encroaching on the sunny side of the lawn. Fast forward 10 years, and the St. Augustine grass was covered with shade. Not only that, but the grass had turned brown. There were bare spots in the lawn that had not been there before.

At first, I suspected drought, but no matter how much I watered, no improvements could be seen. I used my fingers to part a thin clump of grass and examined the base. I saw hundreds of tiny insects, the largest of which was barely an eighth of an inch long. The body was dark, but short white wings could be seen folded flat on top. I spotted smaller insects that were red.

I had chinch bugs. After a few minutes of thought, I did not reach for a bag of lawn insecticide. I had enjoyed the lightning bugs flashing over the lawn recently. I remembered the ground bees emerging from the soil to pollinate my blueberries during the last spring. Good gardeners should always keep in mind that their actions rarely affect only one part of the ecosystem. I like lightning bugs and the bees that work for me, so applying insecticide to control chinch bugs would have affected both. Consider this for your situation.

Q: Could you suggest an umbrella-shaped tree with large leaves that would provide shade in an area that gets full sun? The tree will be planted in a container 4 feet wide. — Marsha Brenner, email

A: I think your only option for an umbrella-shaped tree that provides shade is bigleaf magnolia because it has huge leaves and can take full sun if the root system is healthy. The container could be a big problem. A tree should be planted so the top of the root ball is level with the surrounding soil. The tree roots would be stressed if planted as you describe. A shrub would be better suited for the space.