Heat Wave Putting our Trees at Risk – Residents and Businesses Urged to Help by Watering
July 29, 2015, Toronto, ON – The past few weeks of extreme heat coupled with lack of rain is putting urban trees at risk, say urban forest advocates at LEAF (Local Enhancement & Appreciation of Forests). They are calling on residents to help the trees along streets, in parks and in their own yards by giving them a much needed drink of water!
“Urban trees offer great benefits during the hot summer months, reducing the need for air conditioning and lessening the strain on our electric grid. Unfortunately, during hot dry periods of summer, they are much more vulnerable than they appear,” says Janet McKay, Executive Director, LEAF. “Often by the time the effects of drought become noticeable, it’s too late.”
Our urban trees act as natural cooling systems, providing shade and reducing temperatures of the surrounding air. Large trees can discharge up to 375 litres of water per day drawing water molecules up through their roots and releasing them out through each leaf surface. Without an adequate supply of water, this process, called evapotranspiration, cannot take place. Leaves may begin to droop or wither, and trees may even begin to drop as the tree tries to conserve water. If it survives the drought, the stress may leave it more vulnerable to pests and disease.
“We desperately need our urban trees to help cool our cities and clean our air,” says Janet McKay, Executive Director, LEAF. “Right now they are struggling to do that because of lack of water. They can’t come in out of the heat like we can. They have to stand there and bake in the sun. The least we can do is give them a much needed drink!”
McKay suggests watering trees in the early morning or evening. Ensure water does not run off onto driveways, sidewalks or streets where it will be wasted. Street trees are particularly vulnerable because they are often surrounded by paved surfaces. “Imagine standing out on the pavement all day in the burning hot sun,” continued McKay. “That’s what our trees are facing.” Businesses can help by watering the trees in front of their stores.
Small or young trees should be given three to four buckets of water every other day. More mature trees should be watered with a soaker-hose or regular garden hose. Water should be allowed to flow slowly from the hose for up to an hour once or twice a week. The hose should be moved around periodically to ensure the whole area under the tree’s canopy gets a good amount of water. Sprinklers should be avoided as they waste water through evaporation and lead to sun scalding on the leaves of trees and shrubs.
“Everyone can help by getting out there and watering the trees around their homes and in their neighbourhoods,” concluded McKay. “The benefits will not only keep our city green, but will ensure our trees are able to keep providing us the shade and cooling we so desperately need.”
For more information on proper tree care or how you can get involved in your community visit, www.yourleaf.org.