My fourteen year old green maple in my garden has not been thriving since last year. It is situated about 5 ft from back of my house. Its top and sides are exposed to sun. My garden faces north and is fenced from surrounding households. Neighbours’ trees provide some shade above the fence area.
It started with a sidebranch facing east having leaves turning brown early and shrivelled off. Despite my adding topsoil and inserting fertilizer spike in early summer, and regular watering, tree has not improved. In fact the thick midportion leaves spent a long time in pale green-white color phase before transitioning to full green. More side lower branches develop early browning and falling off.
Any suggestions?
Thanks.
I’m sorry to hear about your tree. It looks like this is a Japanese green maple. It sounds like your tree is experiencing a combination of environmental stress and possibly some care issues. Here are some suggestions based on core categories of tree care (and two key Toronto Master Gardeners resources – The Toronto Master Gardeners Guide for trees called “Planting a Tree for Life” and a specific guide to growing Japanese maples called “Growing Japanese Maples“):
Watering: While we have had days with significant rain this year, we’ve also had long periods with no rain. Ensure your tree is getting consistent and deep watering.
Sun exposure: While your tree gets some sun, it might be too much for it, especially in the afternoon. The shriveled leaves could be a result of leaf scorch. Prolonged high temperatures, hot and drying winds, and low rainfall are the most common reasons for leaf scorch.
Soil (and fertilization): It’s good that you added topsoil and a fertilizer spike, but be cautious with fertilization. Overfertilization can cause leaf burn and other issues. I can’t see the base of the tree but it appears there is grass up to the base of the tree. Ensure you clear an area the width of the canopy under the tree where you don’t have any other plants (so that other plants aren’t competing with the tree for water and nutrients). Also ensure that the root flare of the tree is not covered by soil. Read more about how to find a root flare at the Colorado State Forest Service on how to properly plant a tree. If the flare is covered try scraping back the soil until you can see it, and follow the suggestions in the article. Apply a layer of mulch around the base of the tree to help retain soil moisture and regulate temperature (but ensure the mulch doesn’t touch the base of the trunk).
Pests and diseases: Check for signs of pests like aphids or diseases which can cause browning and leaf drop. There is a good list of Japanese maple pests and diseases at this Gardening Know How site.
Pruning: Remove any dead or diseased branches to improve air circulation and reduce the risk of further issues.
Given the specific symptoms you described, it might be helpful to have a professional arborist take a closer look to provide a more accurate diagnosis and tailored treatment plan. To find an arborist in Toronto please see the Trees are good Find an arborist site.
September 2024