Help! My Cherry Tree Is Oozing!

I was warned by people a heck of a lot smarter, and far more experienced, than me to choose anything other than a purple leaf sand cherry. But the temptation was too great. Tall, dark and cheap. Sold! Ten years ago, my gardening brain was more like that of a teenage girl hell-bent on the bad boy. No one could dissuade me. I thought I could change him, mold him in such a way that would extend his notoriously short lifespan. Pests? What pests? His care would be so suffocatingly complete that he’d thrive and do exactly what I wanted. After all, isn’t that what gardeners do? Force plants that would never cohabitate in the real world to mingle and look good doing it. In the cherry’s case, I wanted nothing more than for him to add some dark foliage interest to the east entrance of my garden. For nine years, he did it without complaint. Until this summer when it became clear that his demise was imminent. Here’s my cautionary tale…

The Courtship

It began innocently enough with a small bed on the side of the house. I wanted an anchor, something dark that I could shape to form a canopy of sorts over my garden’s east entrance. The price was right and I planted a spindly purple leaf sand cherry (Prunus x cisterna) in May 2009. Being the impatient gardener that I am, his fast growing attributes were appealing, but also a throbbing red flag that I chose to ignore. He was delivering the goods and I was happy to overlook his longevity issues.

As the months turned into years, I limbed him up so that his branches arched over the gate. He was perfect and all who entered that side of the garden commented on his handsome shape.

I was always careful to disinfect my pruners so as not to introduce disease. For nine years we carried on this way. Perennials came and went but the cherry remained steadfast. Little did I know that each time I wielded the pruners and made another cut, the lesser peachtree borer (the caterpillar of the clearwing moth) heard the knock of opportunity. The welcome mat was out and the moth moved in, laying eggs at the base of the tree and on the trunk. Wounded bark, pruning cuts and cankers are the only areas where the borer can establish.

The Beginning of the End

The lesser peachtree borer is a pest of all fruiting and ornamental trees in the Prunus species, including peach, nectarine, plum, cherry and apricot. The moth deposits its eggs either at the base of the tree or along the trunk and branches. When the larvae hatch, they burrow just beneath the bark to feed on the cambium, or inner layer of bark, and remain there through the winter. They emerge as moths from May to September and begin the cycle again. Their giveaway is the marmalade-like frass (or poop) that oozes from the trunk and infested branches. The treatment window is narrow, beginning around June 1 and ending Aug 15. An insecticide painted on the trunk and branches during the egg-laying stage would have prevented further harm. Unfortunately, it couldn’t repair the already extensive damage. The infestation had become too severe.
And if that’s not enough, large bulbous cankers are girdling the main branches. The death warrant has been signed and a new kid is moving in this fall. It’s serendipitous really.

As I was considering replacements, a package arrived from Iseli Nursery in Oregon. It contained a North Wind maple sapling to trial in my garden. The tree is part of the company’s Jack Frost collection and sports palmate red leaves in spring, transitioning to green by mid-summer with striking pink samaras, then shades of orange and scarlet in time for autumn. It’s a smaller tree with excellent cold hardiness to zone 4. While not as fast growing as the cherry, North Wind averages 12-15 inches per year. I’m all in and much more reasonable these days. Only time will tell how this relationship will pan out, but I’m hopeful it’s a long-term thing and the garden approves.

Have you made some poor garden decisions?