By Tim Johnson
Special to Tribune Newspapers
January 17, 2013
Q. I have had some problems with plant diseases in the past and wanted some advice on how to get them identified. --Tom Hansen, Libertyville
A. In order to get an accurate diagnosis of a plant problem, it is important to provide a good sample along with supporting information about the site and cultural practices for review. The more complete your sample is, the better your chances are of getting an accurate and helpful answer. It is best to collect and submit fresh specimens. If you are unable to mail or bring a sample in immediately after collecting, then place it in the refrigerator to hold until shipping is possible.
Avoid mailing samples on Fridays or Saturdays to help ensure that they remain fresh. Ship the specimens in a plastic bag enclosed in a crush-proof package. Collect a large sample of 6 to 12 inches in length. Include plant material that is healthy, in decline and infected. It is much more difficult to diagnose a small sample that only includes the affected part of the plant.
Provide as much information about the plant as you can, including where it is planted, how much light it receives, watering practices, age, chemical treatments, type of soil and pruning practices. If possible, include photos of the plant and site. This background information will be useful in determining problems and subsequent solutions.
When you would like to have a plant identified, a good sample of 6 to 12 inches that includes any flowers, buds and fruit is important. Digital photos also work well, so include an overall shot of the plant along with close-ups of leaves, flowers, buds and fruit.
If you need help with a plant problem, bring or send your plant sample to the Chicago Botanic Garden's Plant Information Service. There are forms on the Garden's website at http://www.chicagobotanic.org that provide guidelines for submitting samples and questions regarding a plant disease or pest diagnosis. To contact the Plant Information Service during business hours, call the Plant Information Hotline at (847) 835-0972.
Wherever you go to seek advice, a complete sample with good supporting information will make it easier to obtain an accurate assessment of your particular problem.