How Can I Permanently kill grass/weeds?

Concrete the area is the only close to permanently way to get rid of grass and weeds and even then they can still grow. Best way professionally is to spray roundup twice a year in the area and heavy before laying the rocks down. Also you can place a barrier under the rocks such as a thick dark plastic area under the rock to stop the weeds and grass from coming through. However in time this can not look too well and has to be replaced.

hi Hippyman, What you can do is remove the sod/weeds with a spade, about 1/2" into root zone. Then put down landscape fabric. Then put you rocks on top. River stone, pea stone, etc. The sod/weeds can be composted or placed at least 6" at the bottom of a garden. To kill vegetaion without removing it, cover the area with plastic. Basically, deny the plant light, water and air. Good luck

put weed stop cloth under the rocks

I don't think there is anything. What I would do is put down Roundup and let the weeds wilt, add Preen, add landscaping cloth and in this case rather than a nice hardwood mulch, pea gravel. Then landscape with the rocks. I saw some mulch made out of recycled tires at both Sam's and BJs that I think would be something long lasting in place of wood mulch if you aren't going to use an area for planting. I think it came in both red and black. Please use all the chemicals according to directions. We don't like the weeds, but we don't want our wells and water ways any more contaminated.

Vinager works real well. and it won't hurt anything.

1 way try to make the grass grow more always works for me if i try to grow grass nothing will grow another way is till in alot of lime (can cause health problems) but the lime can eat all the grass roots out of the ground if it is a smallish area say 4ft by 8 ft lay a piece of plywood down starve the grass of light salt the ground can be tilled in road salt might work lots of table salt will the slat and the lime will kill just about everything and wont let anything grow back so be sure oh and the lime can eat your skin off so take protective precautions AND KEEP THE KIDS AWAY FROM IT

Ditto, i'm interested in this too. I have some grass that keeps coming through an empty garden bed and my hubby has used boiling water, acid and petrol and it still wont die. So frustrating.