Knowledgebase
Where to start #930499
Asked May 04, 2026, 5:22 AM EDT
Hennepin County Minnesota
Expert Response
Several things can cause bumpiness. Most common are tree roots and night crawlers. But other critters can leave lumps. And so can grubs, although they would not be high on my list. Read here about bumpy lawns:
https://yardandgarden.extension.iastate.edu/how-to/bumpy-rough-lawns
https://apps.extension.umn.edu/garden/diagnose/plant/turf/bumps.html
As for the bentgrass, without knowing how much of your lawn is affected, it is hard to say how to proceed. If more than half the lawn is weed, we recommend starting over. That means killing everything there, usually with glyphosate, then replanting. If the lawn is less than half weed, here is a good source of information about control of perennial grass weeds:
https://hort.extension.wisc.edu/articles/perennial-grass-weeds-in-lawns/
Treatment for grubs is not usually necessary. You need to first decide if grubs are a problem before applying pesticides. Read here:
https://yardandgarden.extension.iastate.edu/encyclopedia/white-grub-control-turfgrass
Here are some further references on growing a lawn:
https://extension.umn.edu/lawns-and-landscapes/lawn-care