With all the hot weather we’re having in Iowa, my bluegrass lawn looks kinda brown. Would a summer feeding help it to green up?
When a lawn is stressed from heat, fertilizer is the last thing it needs. Cool-season turf grasses, including bluegrass, fescues, and perennial rye, slow their growth in response to hot weather. If the weather is dry as well as hot, you’ll notice a lot of brown blades among the green. This summer “dormancy” can last through Labor Day or until cooler weather and fall rains prompt a return to green.
You could keep the lawn green through summer with copious amounts of water. But I would argue against that sort of wastefulness. Instead, why not take a break from mowing and allow the lawn to go dormant?
There’s one caveat to letting the lawn brown out, and that is the chance that patches of turf will die if the weather stays dry for too long. A good soak every 2 or 3 weeks is all it takes to keep bluegrass alive. Depending on your soil type and how dry the soil is to begin with, it could take between one-half inch and one inch of water to soak the ground to a depth of 6 inches. If natural rainfall fails to provide this much, you’ll have to step in. Apply water in the early morning, when less will be lost to evaporation, and water slowly so every drop sinks in.
Other summer strategies for keeping a lawn healthy include setting the mower blade high—up to 4 inches—and using a mulching blade that drops finely chopped clippings back on the lawn.
Save the fertilizer for fall. Bluegrass and other cool-season grasses naturally regenerate in fall, when temperatures drop and soil moisture is more abundant. In fall, bluegrass will devote the extra nutrients to extending and thickening its root system instead of producing more top growth. Choose a slow-release organic product. —Doug Hall