This workshop is an update of “The 22 Questions of Plant Diagnostics,” this time focusing on the many difficulties encountered with the diagnosis of plant problems. It also features a mystery: Question 23. Plant problem diagnostics is a key to good tree health care management and a precursor to proper and effective arboricultural treatment.
Diagnostics is a Socratic process that begins with key questions about the plant: addressing plant identification, what is normal for the plant, and what are the common problems for the plant. It proceeds through a list of systematic questions about signs and symptoms, aspects of the site, information from those who know the plantings best, and a constant asking of the “what else?” question about what might be involved with why this good tree has gone bad.
This three-hour workshop, modeled on programs we have given at conferences and to nurseries, tree care and landscape companies throughout the U.S., makes extensive use of samples and case studies. Environmental and cultural problems, pests and diseases, herbicide or chemical injuries, and other problems will be addressed. We will also address the problem of diagnostic hubris. The key to diagnostics in understanding the limitations diagnosticians often have and the mistaken lure of being a one-step know-it-all.
Many a diagnosis has gone wrong because of the failure to properly answer one of the 22 questions, such as the true identity of the plant and whether what is seen is normal or abnormal for that plant, or whether the “common problems” question is trumped by a new problem. The only truly sure-fire rule of plant problem diagnostics: there are no sure-fire rules. But asking the 23 questions is a big help.