A year ago we tilled up our soil, layed down weed block and covered it all with recycled glass sand. Now half of the yard is covered in nut grass. Spraying with Manage has not touched it. We began digging it up and realized these nuts are NUTS!! and spread prolifically.
As I have been researching like crazy, I am considering two options. One is using heavy dosing of dry molasses repeatedly, OR salinating the soil and possibly including rock salt in the sand. How horrible is the salt for the soil? We won't be using that dirt for anything else (except there's a few yuccas and a tree), but what are the repercussions in the distant future? Can it be restored? Will it kill the yuccas and established tree?
Anne - There are certain times of the year when nutgrass is suceptible to herbicides. Read the labels, follow the directions exactly and be patient.
"Repeat applications will be required for control, as there are always dormant tubers not affected by the treatment which can sprout later in the season."
DO NOT USE SALT! You will kill everything and it's hard to get rid of - not impossible, but it's a solution with long-term problems attached.
Weed block isn't thick enough, you need something like 30 layers of newspaper with the glass sand on top to even slow it down. I would use vinegar at as strong a concentration as possible - at least 15% acetic acid and preferably stronger.
I keep pulling mine, but don't have a lot so haven't worried. I do remember pulling that weed and putting it into a zip-lock bag and laid it down on some grating. Forgot it and at the end of the summer I found it again, alive and well setting in the hot sun all summer without any soil or water. I do remember our local Radio Garden person saying there is a herbicide that will do the job but a small bottler runs around $50 and will last a very long time so you would need to find some one else to share the use and cost? I don't know if salt would even slow it down as it seems to do well even on the coastal areas.
