Jay from Phoenix, Az writes
Stoning yards in Phoenix ... no grass and we want it to stay that way.
The best way to treat under the landscape would be to remove the rocks and treat the ground below it before replacing the rocks so that you can be sure the herbicide actually reaches the ground below it. If you are able to do this, and there are no desirable plants in the area, then you could use a product such as Martins TVC, which will prevent new plant growth for up to a year when used on the bare ground itself. (You would not want to try to spray this product directly on the rocks because of its blue color.) If you only get occasional weeds popping up, then it would be easiest just to spot spray as needed with a non-selective post-emergent such as RoundUp QuikPro. You may have luck using a granule pre-emergent which is then watered into the ground, but it would be very important to use a high enough volume of water to carry the active ingredient down into the ground. If the rock layer is thick, then this would not be effective. Keep in mind that many pre-emergent herbicides have a dye in them that could stain the rocks, as well. If you would like to tell us more about what specific weeds you are targeting and how much area you need to treat, then we would be happy to make a more specific recommendation for you.
Answer last updated on: 11/26/2018
