Grub treatment and lawn treatments - Ask Extension
Hello! I have read all your pages on Grubs along with asking others questions. I am still not clear on whether it makes sense to try to treat grubs ...
Knowledgebase
Grub treatment and lawn treatments #849016
Asked September 07, 2023, 1:54 PM EDT
Hello! I have read all your pages on Grubs along with asking others questions. I am still not clear on whether it makes sense to try to treat grubs this Fall as the window is closing. I have a 2 lot yard in Robbinsdale and had a fairly good yard/ lawn till this last year. My creeping charlie, Voles and Sumac Feas seem to be better under control. I fertilized in Spring with Triple X Scotts. My neighborhood was hit with Grubs the last 2 years. I treated them with Grub X in Spring but still have some areas where I believe they are present. There are many articles that say to Treat the grubs in Spring for preventive and then other places that say to treat in Spring and Fall. I read your page about grubs and went to review some of the products and am still not clear as to best approach for Fall. I know I probably need to fertilize, arate and treat grubs and do some seeding or overseeding. I have a sprinkler system. Could you please advise me on the grub issue first and foremost and then an order of what I should do given what I have listed?
Thank you so much. My phone number is 612.823.1070 if you prefer to talk. Many thanks Cindi Claypatch
Hennepin County Minnesota
Expert Response
It depends on which grub you are dealing with. Identification is crucial because different methods work best for different types of grubs. If they are Japanese beetle grubs they are best treated in June/July as they emerge. You can do rescue treatment in September hoping to catch them before they go deep into the soil; but it is not as effective. They are too far from the surface in the late fall to treat effectively.
https://extension.umn.edu/yard-and-garden-insects/japanese-beetles
If they are other white grubs they are best treated in the summer before they go deeply underground for the winter. Preventive insecticide treatments should be applied from late May to early August. The insecticide must be watered in with irrigation or rainfall to be effective (0.5-inch minimum). Applications after mid-August and in the spring time, when grubs are fully grown, are not effective.
https://extension.umn.edu/news/white-grub-control-lawns
The key to grub control is knowing which grub you are dealing with. It can get very confusing if you are not aware of the differences. See:
https://extension.umn.edu/yard-and-garden-news/fall-turf-grass-problems-grubs-might-be-culprit
https://extension.umn.edu/yard-and-garden-insects/japanese-beetles
If they are other white grubs they are best treated in the summer before they go deeply underground for the winter. Preventive insecticide treatments should be applied from late May to early August. The insecticide must be watered in with irrigation or rainfall to be effective (0.5-inch minimum). Applications after mid-August and in the spring time, when grubs are fully grown, are not effective.
https://extension.umn.edu/news/white-grub-control-lawns
The key to grub control is knowing which grub you are dealing with. It can get very confusing if you are not aware of the differences. See:
https://extension.umn.edu/yard-and-garden-news/fall-turf-grass-problems-grubs-might-be-culprit
