In some homes, March and April are thought of as the beginning of the lawn care season. After all, the grass plants are coming back to life, greening up and giving a welcome change to the brown hues of winter. The same is true of September; lawns are usually browned out from disease, insects, drought, heat, etc. and a little attention is due to them. Here’s what to do:
First, it’s aeration time. Core cultivation serves to open up the turf, increasing air penetration, prunes and stimulates roots, relieves compaction, and sets it up for fertilization and overseeding. Aeration is a bit invasive, which necessitates that it be done at a time that is conducive to recovery. September is that time.
After 3 months of a gradually decreasing fertility level, applying 0.75 to 1.0 lbs. N per 1,000 sq. ft. of a slow release product for cool season turfs such as turf type tall fescue and Kentucky bluegrass is warranted. However, if the lawn is buffalograss or zoysiagrass, none should be applied as it should be allowed to begin its winter shutdown, without encouraging new growth. For bluegrass lawns, fertilization at this time will enhance the spread of rhizomes.
September is a good time to check the lawn for thatch levels. Thatch is a necessary evil, in that a thin layer is helpful for resiliency and separation of the turf from extreme heat, however if the layer builds up to much, the roots begin to grow in it rather than the soil. If the layer exceeds 3/4th of an inch, use a powerrake to remove it. Or if you want a really good workout, a hand thatching rake can be used as well. After thatch removal, overseed to replace damaged and removed turfgrass plants.
Two turfgrass diseases are commonly seen in September, powdery mildew and stem rust, both foliage diseases. Unlike most other foliar diseases, powdery mildew does not require free moisture on the leaf blade. It appears as if turf blades have been dusted with flour and causes a thinning of the stand. Best control efforts include applying a fungicide in advance of the infection and increasing the air circulation in the landscape. Stem rust commonly occurs on under-fertilized turf as is common in late summer. In many cases, control can be achieved through proper nutrient application described above.