I have this 35-year-old tree in my front yard in Lake Zurich that is not doing well. Do you think the ivy is causing the demise of the tree and if I were to remove the ivy around the trunk, is there a chance it would recover?
— Bert Gaide, Lake Zurich
Thanks for writing in, Bert. We at the Garden often speak about planting trees and shrubs that are best suited for our Chicago-area climate. The tree in your photo appears to be a Douglas fir, which does not perform well here. I planted a few, but they grew poorly, declined within five years, and were removed soon afterward. Your tree is in decline, and I would not expect it to improve with any intervention, both because of age and the species. The shade trees on the side of your photo seem to have been growing over the years and increasing the amount of shade, which resulted in the loss of branches. Removing the shade trees will increase sunlight, but the tree would not grow any new branches on that side. The ivy growing at the base and on the trunk of the tree is not causing any problems, but it could be masking a visual clue on the trunk. If you like the look of the ivy, there is no reason to remove it.
It looks like a 3- to 4-inch raised circular bed was created around the tree some years back. Adding soil around the trunk and roots of a tree can create stress for the tree and should be avoided. This is not worth correcting now, as you would lose all the ivy and it would not improve the tree’s health.
To improve the growing conditions for your tree, carefully prune adjacent shade trees to increase the amount of sun. I would not compromise the shape or health of these trees though, as the existing fir is in decline. Consider fertilizing annually and providing supplemental water under the drip zone and a bit beyond when there are excessive dry periods. The drip zone is the area under which rain will drop off the crown of the tree.
For more plant advice, contact the Plant Information Service at the Chicago Botanic Garden at plantinfo@chicagobotanic.org. Tim Johnson is senior director of horticulture at the Chicago Botanic Garden.