Aerate, dethatch, mow and feed an Idaho lawn

What to do

1. Core-aerate compacted, high-traffic or poorly infiltrating soil while grass is actively growing; spring or late summer/early fall are the usual windows, with early fall often preferred.
2. Measure the thatch layer. University of Idaho guidance treats more than about 1/2 inch as excessive; aeration may help, while power dethatching should be reserved for a demonstrated buildup.
3. Mow with a sharp blade at the appropriate height for the grass—commonly about 2 1/2–3 inches for cool-season turf—and remove no more than one-third of the blade at a mowing.
4. Leave ordinary clippings when they disperse; University of Idaho notes that clippings decompose and do not create thatch.
5. Before fertilizing, identify the grass, consider a soil test and follow University of Idaho guidance plus the exact product label. Avoid overapplication, heat-stressed or dormant turf, frozen ground and application before heavy rain.
6. Sweep material off pavement, keep it out of drains and water, and use a licensed lawn professional when diagnosis or application is uncertain.