Q: I am concerned about my ‘Rising Sun’ redbud planted in June 2017 in my front yard in full sun. It appears to be getting scorched and has started to drop leaves. Sue Weinshenker, Atlanta
A: June is not a great time to plant a tree because it takes a lot of effort to keep it watered properly in the following summer heat. My guess is the root system of your tree has not expanded very well since it was planted. Leaves should not be scorched now. You can probably nurse it back to health by watering deeply once a week and covering the soil out to the drip line with wood chips. Do not fertilize. This will only add stress to the tree.
Q: I’d like to nominate a champion tree but I cannot imagine how to measure the height of our trees that go back to the 1800s. Any suggestions about getting help with that? Barbara Knott, email
A: I think it’s high time you hired a certified arborist to check your trees for health and safety. If they are as old as you think, there will inevitably be faults that will be easier to cure now than later. When you hire them, ask if they might bring a clinometer, which is used to measure tree heights.
Q: What can I use to clean a green mold off landscape rocks that have Zorro zoysia growing around them? I don’t want to hurt the grass with the wrong chemical. Jeff Thomas, email
A: Iron, in plant-available form, is toxic to mosses, green mold, and some broadleafed weeds but is a fertilizer for grass. Products such as Moss Out (ferrous ammonium sulfate) can be used to control moss, etc.
Q: What is the best way to get rid of Japanese beetles on my 30-foot-tall Princeton elms? Eileen Borkovich, email
A: Japanese beetles do sometimes feed on elm trees, but if you are seeing large portions of the tree with lace-like leaves, you have a different insect present. The most likely culprit is elm leaf beetle. The large brown larvae of this beetle feed voraciously on leaves in summer, leaving a skeleton of veins. Trees appear “burned” and brown.
In fall, the larvae crawl down tree trunks to pupate and spend the winter in soil. One way to control them is to spray landscape insecticide on the trunk so larvae are exposed on the way down. They are not common every year, but damage sometimes can be severe. A friend had the top two-thirds of his elm chewed up last year, but there’s been no sign of the critters this summer. Predators and parasites normally keep populations of elm leaf beetle down.
Walter’s email address is georgiagardener@yahoo.com. Listen to his comments at 6:35 a.m. on “Green and Growing with Ashley Frasca” Saturday mornings on 95.5 WSB. Visit his website, www.walterreeves.com, or join his Facebook Page at bit.ly/georgiagardener, for his latest tips.
About the Author
