We all love a lush green lawn. But there’s only so much we can do when the dog days of summer arrive with record heat and lately, record drought.
It can be frustrating to watch our lawns turn from lush green to crumbling straw during a stretch without rainfall. When coupled with watering restrictions, it can be disheartening to say the least. But there are strategies we can use to get our lawns safely through the heat of summer and drought until rain returns and cooler temperatures prevail.
How much water does a lawn need in summer?
In the heat of summer, cool season grasses turn brown. It’s what they do and is not necessarily a sign of a dying lawn. Warm season grasses on the other hand will stay green during summer, assuming your heatwave isn’t extreme and you’re not in a severe drought.
You might be surprised to learn that lawns need very little water in the heat of summer to survive. As they’re dormant at this time (responsible for the brown color), growth above and below the soil line nearly comes to a halt. The grass slows its growth to conserve water so that when cooler temperatures return, it has the resources to start growing again.
When dormant, a lawn only needs about 1/4-1/2 inch of water every 2-4 weeks (0.63-1.2 cm). This is enough to maintain moisture in the roots and crown to let the turf survive until conditions improve. It’s certainly possible to keep the lawn lush and green during this time, but it will require inches of water every week at a time when water is becoming a scarce resource.
How to maintain your lawn during a drought
This is the sort of thing that people who love to tinker hate to hear: do less.
If drought is a persistent problem, consider an alternative to lawn turf.
Turf planted in arid areas and areas prone to drought is no longer sustainable, and probably never was. Consider replacing your turf grass with native plants that are drought resistant and appropriate for your region. This will not only conserve water but will be much easier from a maintenance standpoint. See our suggestions for lawn replacement here.
Mow lawns higher in the summer heat and less often.
During the dog days of summer, only cut your lawn if it’s reached 3″. This might not happen for 3-4 weeks if it’s very hot and without rain. Set your mower deck to 2.5″-3″ (6.3-7.6 cm) so that mowing is less frequent, but regular. Taller blades of grass benefit the lawn by shading the soil to conserve moisture and insulate grass roots. If you have lots of thatch in your lawn, drought stress will show up a lot sooner. Rake out the thatch, aerate your lawn, and add compost to stimulate the biological activity at the soil surface to get rid of it.
Use a sharp mulching blade on your mower
Bagging grass clippings is such a waste. Mulched grass clippings feed your lawn, return organic matter to the soil, and insulate the soil.
Water efficiently.
Never water your lawn if less than 3 weeks have passed without rain. If you water, only do so when the grass begins to wilt (wilting leaf blades fold in half lengthwise and take on a bluish-gray color). Water early in the morning – right after dawn – when the grass can most easily use it and very little water will evaporate. And water deeply and infrequently – this is far more effective for the grass than watering a few times a week for a short time each. If you do turn on the spigot, water gently – only apply it at a rate at which the soil can absorb it. If the soil is baked hard from summer heat, water very slowly to give it time to soak in. Otherwise the water will run off your soil like it does the sidewalk. Use a rain gauge to measure how much water the lawn gets (1/2″ or 1.2cm should be your goal and no more) and do not overwater.
Never fertilize your lawn in summer heat or drought.
If your lawn is in any condition to use the nitrogen (it may not be), the fertilizer will cause a flush of top growth, which is exactly what you don’t want at this time. Wait to fertilize until temps cool and rain returns in the fall.
Sources: Managing Lawns During Drought, University of Illinois Extension; How Do I Keep My Lawn Alive in a Drought?, University of New Hampshire; Lawn Care During a Drought, South Dakota State University Extension; Lawn Management During Drought, University of Florida Gardening Solutions; Lawns: Care During Drought, Royal Horticultural Society; Home Lawn Watering Guide, University of Missouri Extension.