Metro DetroitAugust 1, 2012
Experts offer tips to keep trees, lawn alive during drought
By Robin Ruehlen
C & G Staff Writer
What is the secret to nurturing your trees, flowers and lawn through the withering record heat and lack of rainfall that is crippling the Midwest?
Watering — and learning exactly how much and how often your greenery needs to be doused each day, while avoiding bogginess and rot.
Lili Ennes of Ray Wiegand’s Nursery in Macomb Township advises people to get to know their soil types and water accordingly.
“Sandy soil drains quickly, so you have to water every single day. If you have clay soil, which holds water well, it needs a thorough soak with a good slow trickle,” she said.
Even the giants in the yard suffer during drought-like conditions — something Ennes said many people don’t realize. Larger shade trees such as maples, oaks, crabapples and cherry trees need at least 70-plus gallons of water per day.
“It goes by caliper size. A tree with a 3-foot caliper needs, at minimum, 50 gallons a day,” Ennes said.
“Michigan State University recommends that if a tree has a 20-foot caliper, it needs 200 gallons in one watering. Sprinklers don’t work well for trees, and running them longer just ends up making your yard boggy. Instead, use soaker hoses and drip irrigation.”
According to Michigan State University Extension’s Drought Resources page, curling and wilting leaves on deciduous trees and drooping leaders on conifers are signs that a tree needs water immediately. Both types of trees may drop leaves or needles under severe stress and encounter leaf scorch — a high temperature injury that occurs when leaves are unable to cool themselves due to lack of water in the soil.
Ennes said she is also a big advocate of the Treegator — a slow-release watering bag that can hold up to 20 gallons of water and connects directly to a tree. Treegators come in different sizes for trees and shrubs, and cost anywhere from $18-$25 per bag.
“Treegators have a slow gravitational feed, and you want it very slow,” she said.
National gardening expert Melinda Myers advises that gardeners learn to prioritize watering for plants and gardens, and make sure that the newest plants, moisture-loving types and stressed plants are the first priority.
Myers also recommends checking container gardens at least twice a day in extreme heat, and moving planters into shadier spots to slow dry and reduce the risk of scorch and heat stress.
“Flowers need shallow, frequent watering up to twice a day, and vegetables too, especially tomatoes,” Ennes said.
“A slow soak is the best, making sure the water gets all the way down to the feeder roots.”
Dormant lawns should remain that way, as taking a lawn out of dormancy with inconsistent watering takes a greater toll than dormancy itself. Myers recommends providing a quarter inch of water once a month in order to keep the crown of the grass alive without breaking dormancy. Minimizing foot and equipment traffic on dormant lawns, and avoiding pesticides or fast-release high nitrogen fertilizers will help keep dormant lawns from damage.
Adequate mulching will also help keep the moisture in the lawn, cool the ground and reduce the growth of weeds. A 2- to 3-inch layer of woodchips, bark, shredded leaves or evergreen needles will improve the soil as it decomposes.
Ennes added that due to last year’s mild winter, gardeners should keep watering their lawns and trees right up until the ground freezes in late fall.
“Some people had their sprinkler systems shut off in September last year, and we were already going through a drought, so trees and plants were already under a great deal of stress before winter hit,” she said.
“Everyone is trying to fertilize their trees now, but it’s best to wait until the week of Halloween for that. Water is the most important thing for trees right now.”