What can be used for safe lawn weed control for a lawn in the woods near wetland/pond?
We live in Isanti County, sandy soil, and live in the middle of 5 acres of woods with a lawn. The perimeter of this lawn entails oak woods (much oak wilt by the way) but also towards the south the lawn slopes down to a wetland where we have a pond. The pond will have frequent stops by waterfowl (mallards/wood ducks), an occasional muskrat, but many frogs as well. We also see a lot of toads in our lawn. I would like to do some weed control on my lawn that is safe for the aquatic life. Through knowledge attained from the extension service, i have achieved a pretty nice lawn for being in the woods but would like to control the weeds (dandelion, lambs quarters, et al) as much as possible. Any safe suggestions?
Isanti County Minnesota
Thanks for your question.
You are to be commended for being concerned about using herbicides around water sources, especially for the safety of animals living there. When used according to the directions on the container, broad leaf herbicides having one or more chemical forms of 2,4-D (look at the ingredient label on the container) are not considered to be a significant threat for animal life. 2,4-D in the soil quickly breaks down. These directions should also say something about use around bodies of water. It is effective when weeds absorb it directly. However there are certain good practices that should be followed when using a broad leaf herbicide around water sources:
1. Use a hand sprayer that can be directed against the weeds themselves. This is in contrast to something that is attached to a hose and the herbicide is then sprayed over the entire lawn. Avoid this latter option.
2. Apply the herbicide when there is little or no wind. This will prevent any spray droplets from being blown into the water.
3. Broad leaf herbicides are most effective when weeds are actively growing (which may or may not be the current case for your weeds) and there is no possibility of rain for at least 24 hours. This latter is especially important when application is done around water sources as it precludes water run off of herbicides into the water.
The following will give you more detailed information about possible toxicity effects of herbicides containing 2,4-D: