Because of record-setting heat and prevailing drought conditions throughout much of the Chicago metro area, many local gardeners have been called upon to establish MASH unit-like priority lists. What plants get water and TLC? What plants are left to fend for themselves?
Why not ask the experts? Heather Green, an arborist with The Village of Oak Lawn, and Heather Blackmore, a master gardener with the University of Illinois extension service, agree the first thing you need to do is let your lawn go dormant.
“You can allow your grass to go dormant and it will do so on its own without any rainfall or irrigation after about six weeks,” Blackmore said. “It will turn brown. Most lawns look pretty crispy, pretty burned out this summer. By the seventh week, you can apply some water.
“But the key is to offer water sparingly. Give the grass a quarter-inch every couple of weeks—just enough to keep it alive. But you don’t want to bring it out of that dormant state. It’s not going to green up in this heat anyway. Let it do that on its own as the cooler weather arrives come fall.”
Tips for Surviving the Drought
1. Prioritize. Trees and shrubs should get most of your attention in these drought conditions, particularly immature trees and recent plantings. Green suggested thinking of the problem this way: Trees are the most costly plants in your yard to replace. And they can provide energy-saving relief by throwing large cooling shadows over the rooftops of your home.
2. Water smartly. A general rule of thumb is to apply one-inch of water per week for lawns, trees, shrubs, flowers, fruits and vegetables. Avoid over-watering. Most mature trees and shrubs can be watered every two weeks.
And know this: When watering trees, focus your watering on the tree’s natural drip line—at the point of the canopy. Green suggests asking yourself this question: Where does rain drip off the leaves?
“People want to water at the base of the tree’s trunk,” Blackmore said. “That’s not where trees take in water, not where the roots are located.”
Green said most tree roots are found spread in a circular pattern around the trunk within 15-18 inches of the ground surface.
3. Slow and steady wins the watering race. If possible, use a sprinkler or soaking hose to circle trees and shrubs throughout your watering cycle. Let them run for 30-60 minutes at a time.
“You want to make sure that it’s slow and at a low rate,” Green said. “You want the water to sink in and go deep. If you’re out there watering with a hose, moving it back and forth, that’s not enough, not it all. It needs to be out there for a half hour at a really slow trickle.
“You could put fire hose pressure out there, but it’s just going to go across the top, into the sidewalks, into the street, which is not going to do you any good. You need gravity to help you bring the water down. The way to do that is do it slowly.”
4. Test your soil. Dig up some dirt and check to see whether it’s moist or crumbly. Take an ordinary screwdriver and use it as a tool to measure how effectively you’ve watered around a tree. Press the screwdriver into the ground. If it goes in easily, the ground is moist. If not, then it’s still too hard and too dry and you need to apply more water. Measure how much you’ve watered.
“This can be done by using a rain gauge,” Blackmore said. “You can get one at any of the big-box stores. They’re not expensive. Shut your water off when the gauge shows you’ve reached that one-inch mark or that target mark. Move your sprinkler to the next area.”
5. Timing is everything. Water during the early-morning hours. This helps prevent the onset of disease and lessens the likelihood of evaporation. Watering during the heat of day is a waste your time, energy and natural resources.
“I can’t tell you how many times I’ve seen that,” Blackmore said. “You’re paying for it to do nothing. You’re sending that water into the atmosphere.”