Landscape and Turf - Diagnosing Horticultural Plant Problems 1.

This is the first in a series on diagnosing plant problems in the landscape.

Diagnosing horticultural plant problems is similiar to being a detective. The investigator must examine and evaluate all clues, establish the facts, and synthesize them into a conclusion. A number of principles can be helpful in solving problems. These include the following: start by being prepared, bringing sampling tools, keeping an open mind, and investigating all possibilities. Gather a complete history. Be diplomatic. Collect environmental data and take adequate representative samples. Keep collected samples in good condition and solicit expert opinions when you're not sure. Diagnose the problem and then help your client correct it. Keep a complete record. Above all else, the troubleshooter must begin with an open mind and learn to investigate ALL the possibilities. Jumping to conclusions is the bane of successful troubleshooting. Don't assume that the current problem is the same as the last similar one. Don't let one of the interested parties lead you to erroneous conclusions. If you're not sure about some aspect of the problem, bring in an expert to help. Difficulty in diagnosing problems can occur when more than one cause is involved. Often symptoms become more severe or damage becomes more severe when a combination of causal agents are involved. Clues to the problem are either signs or symptoms. Symptoms are the external and internal reactions or alterations of a plant as a result of a disease or insect. A sign is either the pathogen or pest or its parts or products that are seen on a host (infected/infested) plant.

Adapted from Diagnosing Horticultural Plant Problems by Derby Walker, Jr., Extension Agriculture Agent (retired); Dr. Richard W. Taylor, Extension Agronomy Specialist; and Robert P. Mulrooney Extension Plant Pathologist, University of Delaware Cooperative Extension.