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March 17, 2011 Volume 32, No. 24

Ready to plant? Network of experts is standing by to help


MU Clinic can diagnose plant-related problems

As the weather warms up and people start thinking about getting plants into the ground, the University of Missouri Plant Diagnostic Clinic is open for business.

The clinic draws on a network of experts to diagnose plant-related problems and provide accurate, timely answers and recommendations. If you have spots on your tomatoes, your petunias are wilting or have any other plant-related issue, send your sick plant to the clinic, said Adam Leonberger, the new director of the Plant Diagnostic Clinic.

When submitting plant samples, send entire plants, roots and all, when possible. “For larger specimens, sample from the transition zone between healthy and symptomatic tissue,” Leonberger said. For suspected tree wilts such as Dutch elm disease, oak wilt or pine wilt nematode, submit live branches 1-2 inches in diameter, cut from branches that are beginning to show symptoms. For oak wilt detection, submit branches exhibiting streaking in the sapwood and keep samples cool during shipment by packing with ice packs.

For plant/weed identification, place the sample flat between layers of dry paper. Try to prevent excessive folding of the leaves and place flowers so that you are looking into the center of the flower. Pack the wrapped bundle in plastic, preferably with a piece of cardboard to keep the sample flat. To make packaging easier, fold tall plants once or twice or cut into shorter lengths. For trees and shrubs, collect a terminal or end portion of a leafy branch with at least five leaves or buds.

For insect and spider identification, place a leak-proof bottle or box in a sturdy shipping container with plenty of packaging material to prevent damage.

Preserve soft-bodied insects such as caterpillars, aphids or mites in a leak-proof bottle with rubbing alcohol or hand sanitizer gel. Do not submit insects in water, formaldehyde or without alcohol as they will readily ferment and decompose. Hard-bodied insects such as butterflies, beetles or bees should be killed by freezing. Cushion specimens in layers of tissue.

“It is important to remember that a good diagnosis depends on a good sample, so don’t let it go bad in the mail,” he said.

Wrap samples with a few layers of paper towels, newspaper or other dry, absorbent material. Excess moisture will cause the sample to spoil during shipping. Use a sturdy box to send your plant. Include a completed sample submission form with your sample. Forms are available at

Leonberger recommends mailing samples early in the week to ensure they arrive by Friday and won’t languish over the weekend.

Mail samples to the Plant Diagnostic Clinic, 23 Mumford Hall, University of Missouri, Columbia, MO 65211.

There is a $15 fee for general diagnosis, insect/arachnid identification and plant/weed identification. There is an additional $10 fee when virus testing or bacterial or fungal isolation are necessary for a diagnosis. Commercial turf and putting green fees are $25 and $50, respectively.

“It’s a small fee for a lot of information,” Leonberger said.

For more information, see