Dutch elm disease (DED) testing is conducted on suspected diseased elms at the Crop Protection Laboratory (CPL) in Regina. Samples are tested for Ophiostoma novo- ulmi, the fungus that causes DED, as well as Dothiorella ulmi, a fungus that causes another disease known as wilt.
More information on symptoms and spread of DED is available on the Dutch Elm Disease webpage.
DED testing is done free of charge for Saskatchewan residents. We do not accept out-of-province samples.
How to Take a Good Sample
- Examine the elm tree. Look for yellow/brown wilting or curling leaves.
- Only sample an elm tree between June 1 and August 31 as infected leaves may be confused with leaves changing colour in the fall.
- Sterilize your pruning tools with 10 per cent bleach, 70 per cent rubbing alcohol, or gas line antifreeze.
- Choose a branch showing symptoms of wilting or flagging. Infected wood may appear to be stained brown. To confirm, peel back the bark and look for brown staining in the sapwood, or just under the bark. While staining is a strong indicator of DED, it is not always present in a diseased tree.
- Select a smooth and straight branch, without any cankers or knots, and that is not dried out or dead. Ensure branch is 1 to 1.5 cm in diameter (about the size of your index finger).
- Cut three to four branches. Each piece should be 10 to 15 cm long (see photos 1 and 2). Please do not send elm leaves, elm trunks and large branches to the lab.
- Remove the leaves and twigs from the cut pieces of the branch, but do not remove the bark.
- Wrap all branch pieces in wax paper and secure with tape to prevent drying.
- If sampling more than one tree, be sure to sterilize your pruning tools between trees. Keep each sample separate and clearly marked/identified.
- Place the sample(s) in an envelope and make sure to include your name, address, phone number and the location of the tree(s).
- Send the sample as soon as possible to:
Crop Protection Laboratory
1610 Park Street
Regina, SK S4N 2G1
Important Points to Remember
- Samples can be submitted between June 1 and August 31 each year. Samples will not be accepted after August 31.
- If the sample needs to be stored temporarily prior to submission, it should be kept in a cooler or a fridge to prevent deterioration of sample.
- Ensure that the sample is taken from a branch showing symptoms; otherwise the results may not be accurate.
When to Expect Results
Testing begins in June. Samples are tested on a first come first serve basis. Results for diagnoses will be provided within 15 working days of the CPL receiving a viable sample.
A positive result means DED is present on the sample and the tree must be removed. A negative result indicates the absence of the disease in the sample tested.
What to do When the Tree is Tested Positive for DED
Dutch elm disease is provincially regulated under The Forest Resources Management Act and is federally regulated under the Plant Protection Act. Trees confirmed to have DED (a positive test result) are to be removed immediately and the wood must be promptly disposed of at the nearest elm tree disposal site. The Saskatchewan Ministry of Environment will be notified of any positive results.
To find out more about Dutch elm disease and what you can do about it, or if you suspect an elm tree has the disease, contact the Saskatchewan Ministry of Environment DED line at: 1-800-567-4224. Contact your local municipal office for more information about infected elm tree or wood disposal sites.