Question
hi William,

On a seperate issue, i'm trying to prevent my crazy neighbors vines from running across my yard.  So i'm thinking about getting some pre-formed decorative rataining wall blocks from Home Depot.

Do i have to lay a layer of gravel or sand before placing the bottom row of blocks?  Or can they be placed right on the dirt without sinking into the ground?

Looking forward to hearing from you,
Wayne

Answer
Hey Wayne, Yes you will have to use some 3/4" gravel as a base for the wall. You want to dig down far enough to put a good 6"-8" gravel base as well as burying half of the first row of block. You will need to or should fill behind the wall with 3" to 4" of gravel up to half of the last block(top one) and before adding the back fill rock you might want to us some of the weed blocking material up against the inside part of the wall. This will help with keeping weeds from growing out of your wall, and it will keep roots from growing through the wall which could really mess your wall up. You don't want to do all that hard work and have some roots making it uneven. You mentioned you were getting the block from home depot. I live in So. Cal. Ocean Beach. There are places named "RCP rock and block", and "KRC brick and block" that sell several type of garden wall blocks that come in many sizes and colors. They a block that is called " legacy block" Very nice to work with and looks great. But more important they are cheaper in price, and they can deliver the block and the 3/4" gravel to your home and put it were ever you tell them. Saves on the back a bit. Not sure if they have those places in your area or not. But it might be worth looking it up in the phone book or on the net. Have fun with your project. And feel free to write anytime. Thanks Bill