I have this low lying weed spreading in some areas. (Pictured - the one that's not clover) I live in Minnesota. Does anyone know what it is and best practices for prevention or killing it without impacting the lawn?
2 Answers
That's creeping charlie, which is very difficult to kill other than by hand-weeding. You could try an herbicide that contains Dicamba, which is as far as I know the only herbicide that will kill it. It will require you to spray every single leaf in order to stop the spread of the weed.
The most likely possibility is Glechoma hederacea, commonly known as ground-ivy or creeping charlie. G. hederacea is in the mint family, so if you check the stems they should have a square cross-section and if you break a leaf you should get a rather distinctive and strong aroma from it.
Like other plants in the mint family, it is notoriously difficult to get rid of because it’s resistant to most targeted herbicides and is difficult to completely remove mechanically because any small piece left behind will tend to re-root and grow back.
The only truly targeted herbicide I know of for this particular weed is triclopyr (sold under a number of trade names in the US, including Garlon, Turflon, and Remedy). However, you have to be careful about potential runoff with triclopyr, as it’s potentially nastily toxic to many aquatic species.
The next best option is dicamba. Dicamba is not exactly a targeted herbicide though, so you will need to be particular about applying it directly to the plants you want to get rid of, and particularly careful around other plants (it will affect most things other than grasses, and is particularly toxic to conifers).
Then there’s always ammonium sulfamate, but that should be the last resort as it will kill essentially all plants in the application area. That said, it also breaks down very quickly and will accelerate the decay of any dead plant matter in the area, so you could then safely re-seed grass in the area a few weeks later.
Irrespective of your choice of herbicide for this, you will need to ensure that it is applied to every single spot the weed is growing. G. hederacea absolutely will come back if you don’t get all of it, and you’ll quickly be back to square one.
