In my garden I have a Camperdown Elm, Ulmus glabra “Camperdownii”, affectionately known to the family as Quasimodo. I first saw this type of tree in California, a beautiful older specimen with drooping branches hanging to the ground in its full summer glory. The photo above is my Camperdown after twenty years. For the first ten years I just thought it was a slow grower. It is hard to adjust to growing conditions up here. For the next ten years I threatened to rip it out every summer as I watched its huge American Elm type leaves turn yellow and new growth slowly die. The year before last I laid down the law, if I couldn’t see improvement Quasi would have to go. That spring I finally noticed scale insects all over the trunk and down a few branches. The enemy thus identified, we three went to work educating ourselves about scale and how we could help our tree. Could we actually save him?
Dormant oil spray seemed to be the least toxic remedy. It is a distillation of a highly refined petroleum that breaks down quickly. Mineral oil is a petroleum product you may be familiar with. Mixing the oil with water works as a contact spray and smothers the insect. We decided to use an all-season dormant oil that can be sprayed throughout a trees life cycle. We decided to spray in late winter as there is no chance of leaf burn while the tree is dormant. Dormant oil sprays need to be applied when temperatures are above freezing for 24 hours. That happens at our elevation of 6,500 feet about mid-March. Moisture breaks it down so it can’t rain for at least a day. We waited eagerly for these conditions to arrive and went for it.
Quasimodo is greatly improved. He didn’t lose any leaves or branches last year. I see him growing in my garden family for many more years. The lesson here is to pay attention to the plants that are not thriving and learn how to help them. I’m embarrassed that I let him suffer for so long but very glad that I finally paid him mind. He would have been greatly missed. My advice this week is to look over your deciduous trees and learn how dormant oil can be used to keep them healthy.
Monika and the boys.