Ask a Master Gardener: Pesticide Drift
This question came via Facebook, and I sadly have personal experience with it. You’re trying to grow native plants and support pollinators however you can, and then your neighbors are spraying chemicals all over their lawn. It’s a super frustrating experience, but let’s break this down and see if there are ways to constructively deal with it.
Question:
My neighbors spray their yard for both mosquitoes and weeds. Is there any way to prevent drift from chemical pesticides and herbicides into my yard?
Answer: This is such a bummer. I did some reading about whether the sprays used for mosquitoes affect pollinators. Here’s what Michigan State University says:
“Fogging or spraying for mosquitoes or biting flies around the yard and garden with an insecticide can be very harmful to pollinators. Even if flowering plants are avoided and applications are made after sunset, insecticides applied as a fog or mist can drift onto flowering plants within 100 meters or more depending on the wind speed and direction. The insecticide drift could contaminate pollen and nectar collected by bees for several days or weeks after it is applied, and the residue on leaves can be toxic to caterpillars for weeks or months. Caterpillars of some species of butterflies are extremely sensitive to insecticide residue on leaves.”
I was afraid of that.
Before we get into solutions, let’s also touch on herbicides, which are slightly less alarming depending on how they’re applied. Technically, herbicides should not affect your pollinators, but you may lose some of your plants that are close to the property line—I have. It might not hurt to ask exactly what they’re applying before getting too alarmed.
Unfortunately, there is very little you can do. It sounds like you’ve already tried politely asking and offering education. Here are a few ideas.
If your neighbors are using a lawn care company for pesticide spraying:
- Call the company directly and ask them to use low-pressure nozzles
- Take before and after pictures to document plants that die as a result of drift, and ask for a refund. I have done this successfully.
- After you contact the company, they will most likely make a note on the account. Since I contacted the company that my neighbors use, I have noticed them acting with more caution than they used to.
If your neighbors are spraying pesticides themselves:
- Buy some lightweight frost blankets. Ask your neighbor for a schedule of when they are spraying or for at least 24 hours notice. Then you can cover plants along the property line with the frost blanket while they are spraying.
- If you have a lot of native plants, consider adding signage to your yard. You could register as a Monarch Waystation or with Homegrown National Park or just buy a pollinator sign at a local garden center. Place it conspicuously as a reminder.
- Ask them to consider granular pesticides instead of fogger-type chemicals for mosquito control. In addition, if they apply pesticides in the evenings, bees will be less likely to be out foraging.
Other things to consider include a buffer strip of grass or wood chips along the property line, depending on how big your lot is. That can also help with any complaints you might get about any of your natives that are a little bit more assertive.
Good luck with this one, because it’s a tough situation maintaining a good relationship with your neighbors while also doing your part for pollinators.
Have indoor or outdoor gardening questions? Ask them in the comments below. If we don’t get to yours, you can Ask a Master Gardener online or call the Yard & Garden Line at (612) 301-7590.
Other helpful resources:
The Master Gardener Volunteer program
Jennifer Rensenbrink is a University of Minnesota Extension Master Gardener Volunteer for Hennepin County. She somehow has two mini-prairies on her tiny south Minneapolis property.
About Pesticide Drifts: We have experienced this problem with urns placed at one of the local cemeteries. The cemetery is surrounded by farm fields and in the last two years we have noticed that the plants in the urns (Big Bronze Leaf Begonias) have been affected. The leaves looked shriveled and unsightly and the plants appear somewhat stunted. We continue to water and fertilize them but it takes a long time before they recover. It’s so disappointing when you put a lot of money and effort into planting the urns only to see them damaged by drifts.
Wished that whoever put the chemicals on the fields would be more careful.
Drift from agricultural applications can be even worse — especially when they use airplanes. In that case I see no other option but to talk to the person applying the herbicide and ask them to be considerate of wind direction.
I’d really like to plant an abundance of native species in my garden, but I am surrounded by neighbors who spray their lawns. If I begin to attract pollinators, could I actually cause more harm than good by effectively leading them into a trap? Or do we think having some edible species in the area is better than nothing (most of my neighbors grow only grass and maybe have a tree or two)?
It’s definitely valid to think you may be leading pollinators to their doom. However, as Jennifer mentioned, learning what times your neighbors are spraying, how they are applying it, and even what they’re applying, could give you some peace of mind. If you can, try to start your plants in an area of the yard that’s away from property lines or sheltered by your own trees, a garage, or fencing, if you have it.
Planting a pollinator garden is still important work, and you could even bring awareness and a thirst for more education in your neighborhood with a managed garden and well-placed signs.
We had a large wasp nest in our garden and fire ants that sent caretakers of the garden to emergency when they were bitten . Removal of these pests required lethal sprays. Months later all the monarch caterpillars are dying. How can I neutralize the garden to save the caterpillar?