Q. My lawn took a beating from last years drought. I have about an 8,000-square-foot lawn, and about a quarter of it looks dead. It has numerous brown patches that dont appear to be recovering. I didnt water at all last year. Was that a mistake? My neighbor told me that my lawn would just go dormant during the summer and would recover in the fall.
A. Lawns established on poor compacted subsoil in urban areas are more likely to not recover from intense summer drought. This phenomenon occurs because of the intense heat that city lawns can experience because they are surrounded by asphalt and concrete. These materials absorb and then radiate heat that can dry out turf more quickly than lawns in rural areas. When subdivisions are built, the soil is bulldozed, rolled, bulldozed and rolled over and over to make a site suitable for home building.
Unfortunately this construction can ruin soil structure, making the lawn site more like a bowling alley. When rain falls on compacted soil, it is not absorbed. Instead, the water runs off into the streets and storm drains rather than being absorbed by the turf.
The bottom line is that most lawns in urban areas can handle about three weeks of intense heat and drought. After that, the turf grass will begin to die if it is not watered.
As I mentioned last year, about a half-inch of water applied weekly to a lawn during a summer drought will keep it alive. It wont look great, but it will survive.
This is the time to renovate lawns that suffered from last years drought. Rake off any dead material. Rent a core aerator from a specialty rental company or hardware store. Run the core aerator in two separate directions. Fill the holes left by the aerator with quality compost or Canadian sphagnum peat moss. After aerating and top-dressing, reseed the area using a premium blend of Kentucky bluegrass with about 15 percent to 25 percent or perennial ryegrass.
This can be accomplished by broadcasting the seed over the area – again going in two different directions. After seeding, cover the area with clean straw. Use enough straw to cover the seed but not so much as to blanket the soil. After seeding and strawing, keep the area moist by spritzing with water so that the upper one-quarter to one-half inch is kept moist. The top one-quarter to one-half inch of soil must be kept moist – not soggy – for at least four to six weeks. Sometimes nature helps by providing rain so we are not outside spritzing all the time.
One can also rent a slit seeder for mildly damaged areas. These devices drop seed into grooves made by the machine, which may also be rented at local stores.
Wait at least six weeks after lawn establishment to fertilize or apply a weed control.
Hopefully, this season will be characterized by abundant rainfall so we wont have to worry about lawn renovation next spring.