Poison ivy

Asked April 26, 2019, 2:47 PM EDT

What is the best way to rid my garden plot of poison ivy? Is there a product other than Roundup? I want to keep the pollinators safe. Are there any natural remedies that you can recommend? One plan I am considering is to dig up the entire area, remove the dirt and roots that are there, and put in fresh dirt. I am thinking I would need to dig 10 inches or deeper. Do you have any advice on this plan? Thank you very much Shauna Tindall

Washtenaw County Michigan

1 Response

There are many reasons why people may or may not want to use certain herbicides. This comment was a new one to me. The research I believe you are referring to (Motta et al. 2018) concluded that when consumed glyphosate has the potential to decrease the density and diversity of the microbes found in the gut of honeybees, making them potentially more susceptible to pathogens. While I am not here to sway you one way or another, I added a comment on how you may be able to minimize this type of exposure in the herbicide comments below.

Careful physical removal of the above and below ground portions (taproot and rhizomes) of the weed may be an option for control. Care should be taken when removing the plants by covering exposed skin. Plant material should not be burned, but bagged and disposed of with trash. Repeated efforts may be needed depending on the size of the plants you are attempting to remove.

The two most popular herbicide active ingredients for poison ivy control are glyphosate and/or triclopyr. These products are most effective when applied as a concentrate to cut stumps (and if the stump is large enough drilling holes in it helps). Examples of such products include Roundup Concentrate Poison Ivy and BioAdvanced Brush Killer Plus Concentrate, though there are many others. Applying the products as a concentrate to the cut stump(s) would minimize the risk of exposing foraging bees to these products due to the reduced treated area and the lack of foliage and flower. Triclopyr is often more effective than glyphosate in controlling poison ivy, however, it would likely pose a carryover risk if you desire to replant the area within the coming season. Glyphosate does not pose a risk to re-planting once dry due to binding with clay and organic matter in the soil. Use caution with these products as they will kill or injure other plants with which they contact green foliage, green bark (non-mature), or exposed roots. Always read and follow the label when using a herbicide for weed control. Both herbicides may require re-treatment, again depending on the size and establishment of this population.

If you have more questions please do not hesitate to reply to this message or email me directly at hiller12@msu.edu.