Editor’s note: Kelly R. Jackson’s Garden Corner column is taking on a new format. He now takes questions called into his phone recently at the Christian County Extension Office and answers them in the column.
Question. I’m finding brown roaches in my house. Where are they coming from and how do I control them?
Answer. Fortunately, brown roaches are what we call accidental invaders. While other types of roaches live and breed in homes, brown roaches, also called Wood cockroaches, prefer moist woodland habitats where they can feed on decaying organic matter. They are very active in the summer and, being attracted to lights, may fly short distances to your home. They can enter the home by crawling under exterior door gaps or gaps around pipe or electrical services, so your first defense should be to seal these gaps. You can also reduce clutter around your home, remove stacks of firewood, and keep the landscape tidy. In severe cases, insecticides can be applied as a barrier treatment around the base of the foundation. There are many commercially available products but be sure to read the label.
Q. What’s causing my azaleas to look bleached out?
A. Most likely, lace bugs are feeding on your azalea leaves. They use their mouthparts to suck out the plant sap leaving bleached white leaves that drop during the summer. You can confirm this pest by looking on the underside of the leaves for the adults or tarry black waste spots. Some damage is tolerable without harming the plant. But when damage is extreme, an insecticide will give you control over lace bugs. Insecticidal soaps and horticultural oils can provide control but you need to spray under the leaves. Other systemic products, like imidacloprid, work by moving through the plant’s vascular system. This can give you season-long control of lace bugs.
Q. My maple has a discolored seepage running down the trunk of the tree. Will this kill my tree?
A. Occasionally maples, elm, oak, birch and a few other shade trees can develop a wetwood disease. Tree owners first notice a vertical streak of wet bark on the trunk beginning at a crack or wound up on the trunk and extending all the way to the ground. This seepage is often accompanied by a discoloration of the bark where the water flows. Sometimes this flow becomes foul-smelling indicating an associated product call slime flux. The quick explanation of what has happened is that bacteria have infected the heartwood and inner sapwood of the tree. The waste produced by the bacteria, namely methane and metabolic liquids, start to build up pressure until they are forced out the nearest available opening, usually a trunk wound or pruning cut. As the fluid runs down the tree, it is feed on by fungi, yeasts and bacteria until it changes to a brown, slimy ooze. Wetwood disease does not appear to directly harm the tree but it does not go away and can be an additional stress to the tree over time. So far there is no effective preventive or curative controls.
Kelly R. Jackson is the Christian County Extension Agent for horticulture. He can be reached at 270-886-6328 or visit Christian County Horticulture online at www.christiancountyextension.com.