Pests and diseases pose a serious threat to our state’s crops, forests and plants, and some may be lurking in your living room.
Wisconsin is one of the top five Christmas tree-producing states in the country — it’s big business here. So keeping all of that greenery — including wreaths, garlands and trees — pest-free is a big job that falls to the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP).
DATCP inspectors start many months before the December holidays, licensing around 2,000 nurseries and Christmas tree farms every year. The least the rest of us who celebrate with live evergreens can do is to help them out by disposing of our greenery properly.
Director of DATCP’s Bureau of Plant Industry Brian Kuhn says a top concern is an invasive pest called elongate hemlock scale (EHS) which show up as brownish bumps on the needles on the underside of the branches. (See photo.)
In both 2018 and 2019, plant health inspectors found EHS at multiple retailers who imported greenery from other states. Pesticides are not effective at killing EHS, which attacks more than 40 evergreen species, including the popular hemlock, fir and spruce.
“You can leave decorations up for the holidays, but we want to make sure consumers are disposing of infested evergreens properly to prevent this pest from establishing itself in Wisconsin,” says Kuhn. “If you know your evergreen did not come from Wisconsin, or it is showing signs of EHS, make sure you dispose of it properly [to protect] our state’s forests and Christmas tree producers from EHS.”
This past holiday season, “infested stock was comprised of fir trees, wreaths, and décor from suppliers in North Carolina with some material labeled as ‘fresh from the Blue Ridge Mountains,’” according to DATCP. Wisconsin retailers who sold these products cooperated in removing them from their shelves and properly destroying them, but many had been sold by the time they were discovered. It’s also possible, according to DATCP, that other retailers had EHS-infected greenery that were not discovered.
How to dispose of holiday greenery
The advice from DATCP’s plant bureau:
The preferred method is to burn an EHS-infested evergreen to kill the pest. Prior to burning, check the Wisconsin Department of Natural Resources website at https://dnr.wi.gov/topic/ForestFire/restrictions.html for any burning restrictions in your area.
The other method is to bag your evergreen wreaths or décor separately and put them in the trash. If your municipality picks up Christmas trees, you may put an infested tree out for municipal pick-up.
To prevent the pests from spreading, do not compost or place infested evergreens in a forest.