Q.Potentillas And Grass
Bushes overtaken by grass. How to get rid of grass?

Certified GKH Gardening Expert
There are a few ways to do so. You can choose chemicals (Glyphosate will be a fast, spot treatment.), or natural methods. Laying cardboard and wetting it, while allowing it to remain for a few weeks will kill the grass. Just be sure to apply a fungicide before you do so, or it could invite infections to the area.
Here are some articles that will help:
https://www.gardeningknowhow.com/plant-problems/weeds/glyphosate-information.htm
https://www.gardeningknowhow.com/plant-problems/weeds/grass-growing-in-flower-bed.htm