According to the calendar, summer is here. But for turf, the ups and downs in temperature and rain since mid-March make it seem as if summer has been with us for months now. Unless you’ve been lucky enough to have your patch of green positioned under an isolated thunderstorm or covered by irrigation, it’s likely now a patch of brown. Many homeowners choose not to irrigate their lawn and after about two or more weeks without significant rainfall, the concern becomes whether or not the lawn might be suffering and possibly approaching death.
For Kentucky bluegrass lawns, which are the majority of lawns in Michigan, there is usually no danger that the lawn is going to die unless water is lacking for six to eight weeks. However, there are really no hard fast numbers for predicting whether the turf will die as many other factors will come into play such as high temperatures and traffic. Even if you are not an irrigator, it might be a good idea to give the turf a little water if the turf hasn’t received any water for a month. Apply about a 0.5 to 1 inch of water just to make sure the lawn makes it through this cycle of drought. The goal of this irrigation is not to turn it green, but just to prevent the turf from completely desiccating (severe drying out) and, possibly, death. If we continue in this dry spell, I would continue to give the turf a drink every three to four weeks at a minimum.
Here are some other helpful tips for managing turf during our current, hot and dry conditions.
Don’t worry about trying to control weeds right now in drought stressed turf. Just like the turf, many of these weeds are slowing down their growth and trying to control them now would be more difficult – besides, they might be the only green color in the turf.
Heat tracks have been everywhere from home lawns to golf courses. Anytime you put traffic from a cart, mower or spreader on turf that is nearing the wilting point or has already wilted, you will likely see a track in the following days or week. For those who have irrigated and still have some green turf, avoid mowing during the heat of the afternoon. Mow during the cooler times of the day, early morning or in the evening after dinner. Also, maintain the highest mowing height possible. Don’t think that by mowing lower you’ll help the turf by reducing the amount of leaf area the roots have to support. Remember, if the turf doesn’t have any leaves, it can’t harvest light for photosynthesis and the result is that more energy will be spent to produce new leaf tissue. Mow high and mow in the coolest part of the day.
If you have an irrigation system, watch the heads to make sure everything is firing on all cylinders.When conditions get dry, gaps in coverage become obvious and green and brown circles are indicative of poor irrigation coverage becoming prevalent.
Soil differences across an area can result in visual differences in turfgrass, very similar to those seen with poorly functioning irrigation systems. Although we would all like to think we have a very uniform soil type to grow our turf and landscape plants in, that is often not reality.
(This article was written by Kevin Frank, Michigan State University Extension, Department of Crop and Soil Sciences.)