Dutch elm disease, oak wilt, Verticillium wilt (vascular wilt) samples 
Collect three branch pieces, 1/2 to 2 inches in diameter, 6 to 8 inches long, from recently wilted branches. Pieces from branches that are partially alive and partially dead are best. * DO NOT * send branches that have dried out and have a brown layer directly under the bark.

Soil samples (Call prior to submission to verify test availability)
Collect soil samples from several locations in a field to be tested. Try to collect a sample that represents the soil from all areas of the field. These small samples (subsamples) can be mixed together for shipment.

Testing for Aphanomyces euteiches races in soils collected from alfalfa fields requires 2 gallons of soil.  For detailed instructions on how to collect this sort of sample, as well as a submission form, see “How to Submit a Soil Sample for Aphanomyces Race Testing on Alfalfa“.

Testing for pea/bean root rot pathogens requires 2 gallons of soil per sample.  For detailed instructions on how to collect this sort of sample, see “How to Submit a Soil Sample for Pea/Bean Root Rot Testing“.

Tree and shrub root samples
Select three to four sites around the drip line (i.e., the edge of where the branches extend) of the tree or shrub. Dig down 3 to 6 inches at each location and look fibrous (small) roots from the tree or shrub.  Roots from all locations can be mixed together for shipment.  A handful of roots is needed for testing.

Turf samples
The PDDC does not diagnose turf diseases.  Turf samples submitted to the PDDC will be forwarded to the UW-Madison Turf Diagnostic Lab for analysis.