Note: Most homeowner samples may be diagnosed by the Master Gardeners or County Extension agents and will not need to be submitted to the clinic at University of Delaware. Please call your County Extension office first.
Examine plants carefully and select leaves or plant parts showing a range of symptoms from mild to severe. Often there is a transition zone between diseased and healthy that may provide the best sample. Select enough material to work with, for example 8 to 10 leaves, or several shoots or branches. For turf samples, please dig out a section containing soil and roots. Try to collect a sample prior to the application of any pesticides.
Place the sample between paper towels or in a paper bag. Then place sample in a zip lock or other plastic bag and label the outside with a name and date written in permanent marker. Refrigerate the sample until shipped, or store in a cool location out of direct sunlight. Many samples deteriorate rapidly.
Use a “Delaware Plant Diagnostic Form Nov2014” whenever possible. The form may be printed from this web site, or picked up at any County Extension office. Complete as much of the information on the form as possible, doing so will assist in a faster more accurate diagnosis. The form should accompany the sample, but not in the same plastic bag as the plant material.
Ship the sample as soon as possible or bring it to the nearest County Extension office. Collect. Ship early in the week, so the sample does not sit somewhere over a weekend. Overnight shipment may be best for some samples. Seal the package well and send to:
University of Delaware
Plant Diagnostic Clinic
151 Townsend Hall
Department of Plant & Soil Sciences
531 South College Avenue
Newark , DE 19716-2170