Diagnosing Plant Problems

"Diagnosing plant problems requires patience"

The above title was posted by Karen Bernhard, Entomologist, Lehigh Co. Cooperative Extension, on November 8th on The Morning Call web site http://blogs.mcall.com/master_gardeners/

Many times the folks at the County Extension office know what’s happening with your plant, lawn, vegetable, shrub or tree because they have received other calls or they are seeing the same problem in their own gardens. Sometimes the information will be posted on the blog.

Sometimes the question is extremely difficult to answer. These are the problems that take time and patience. Is it caused by a bug, a virus, bacteria? Or is it cultural – the weather, site problems, hardiness problems, problem with sprays, or a host of other reasons?

In the Master Gardener Blog, a helpful questionnaire is posted under “Garden Resources” in the right-hand column. Click “Send Questions to a Master Gardener.” Click again on “Submit your questions online”. The form will give you some idea of the information needed to accurately assess the problem.

If it is a really difficult problem, you may be asked to bring a sample. Take as much of the plant as you can. Often the answer is in the transition zone between the good growth and the problem zone. Sometimes it is even in the roots. The samples will need to be fresh. If you can’t get to the office right away, store the sample in a plastic bag, keep it cool and get it there as soon as possible. When you call, the people at the Extension Office will advise you how to handle the specimen.

A helpful guide for the do-it-yourself gardener “A Guide to Diagnosing Diseases of Landscape Plants” Virginia Cooperative Extension http://www.ext.vt.edu/pubs/plantdiseasefs/450-800/450-800.html

If you have a difficult problem, be prepared for a tough answer.

- Sometimes there is nothing you can do. The plant is toast.
- Treatment may be delayed until another season. A pesticide may only work at a certain stage of the insect’s life.
- Sometimes there’s nothing you need to do. It will eventually go away.

Hopefully, the people at the extension will be able to provide a plan of action and not a dire diagnosis.