Storage Didn't Cause Gladiolus Color Change

Q. Last year I had many different color glads. Over the winter I stored the bulbs all together in mesh bags, but this summer most of the bulbs produced the same color - a salmon hue. Did storing the different colors together cause this?

A. Storing your gladiolus corms together certainly isn't the cause of them changing color. Each corm is genetically programmed to be a certain color and this is not likely to change unless something causes those genes to go bananas. There is a disease called white break, caused by the cucumber mosaic virus, which can cause the color change you describe. Aphids are often the disease vector, so controlling them may prevent future problems. It's probably best to get rid of your glads and start over next spring with new corms.

Q. I've noticed some trees in my neighborhood infested with what appear to be tent caterpillars. Is this possible?

A. The life cycle of the western tent caterpillar limits the time that it injures plants to the spring period. Their activities are over by the end of June; however, usually by late July another caterpillar begins to feed on trees and create those ugly webs. This bug is called fall webworm, the larval stage of a quite attractive white and orange moth often seen at outdoor lights in the evening. Females lay eggs on host trees like willows, poplars, walnut, fruit trees and cherry laurel. These hatch out into yellowish-brown, long-haired caterpillars that feed on the foliage within the webs that they spin. Usually only one branch, or part of a branch, is enveloped in the web, but a really serious infestation may cause large portions of a tree to be covered with webs. The webs obviously help protect the worms from predatory insects, like yellow jackets, as well as birds.

WSU Extension entomologists recommend controlling them mechanically, if possible. Clipping out the infested branch before the webs become too large may be possible without destroying the symmetry of the plant. Various chemical insecticides are labeled to control this pest, but B.t., Thuricide or some other brand of Bacillus thuringiensis will work, if applied while the larvae are still small. Sprays must be applied forcefully to penetrate the webs and coat the foliage.

Gardening runs Friday in the Scene section and Sunday in Home/Real Estate of The Seattle Times. It is prepared by George Pinyuh and Holly Kennell, Washington State University/King County Cooperative Extension agents, Mary Robson, Master Gardener program assistant, and volunteer Master Gardeners. Send questions to: Gardening, The Seattle Times, PO Box 70, Seattle, WA 98111. Questions of will be answered as space allows.