Hi, I built my raised boxes with un-treated wood solid at the corners and lined the bottom with small gap chicken wire and garden black weed cloth. I am cleaning and covering mine up so I can just add a bit of water is needed and go! I saw on a page where a man took bales of straw (not hay, didnt want to chance seeds) and made a large bed using the bales. he then put down more straw, newspapers, organic compost and dirt ... all the good things in life. (I make my garden mix with 'mels mix' from square foot gardening. I have roots that push up up become little trees (I trip on them all the time) My neighbor told me to round up the buggers. Check into vinegar, . pull the root up as far as possible and with someone you trust, have them whack it off with a hatchet. I believe you can then add vinegar, BUT it will make the dirt sterile for 2 years. boy, I hope some of that makes sense. Maryann

How about this polyethylene and pvc pipe greenhouse to go over your raised bed? Here is a link that might be useful: pvc greenhouse plan

I found surface bond cement worked quite well, and was fairly easy for a first time user. It did not require leveling every block. Just level your ground and dry stack your blocks, and spread it on the outside/inside. Quickrete, and sakrete both have a version that is available and Lowes and Home Depot. http://www.quikrete.com/ProductLines/QuickwallSurfaceBondingCement.asp http://www.sakrete.com/products/detail.cfm/prod_alias/Surface-Bonding-Cement I would (did) use full size blocks 8X8X16 they are not that much bigger and you can grow lots of stuff in the blocks. I have strawberries, Garlic, and about every herb doing quite well. There is a pretty big jump in stress adding the 4th row. I would discourage the 4th row (32"). Unless you have a level or solid footer, or plan on using mortar to help level it out. The flaws get magnified with every row, and for my dry stacked blocks the 4th row was really tough to get level. For my gardens the 32" garden has seen settling and winter/summer cracking. My 24" 3 row stack gardens have not. As for reinforcing the walls maybe pour the corners solid with reinforced or fiber "crack resistant" cement. The ready mix cement is not the difficult to mix, just add water and mix until it is workable. After completing my gardens I had to ask myself how much am I going to save my back by having high raised beds Vs. the gardening on the ground. I think in another 10 years I will break even. Though in my area the raised beds have worked wonders at keeping the bugs/ nematodes away.

I have several raised veggie beds without weed barriers and they do get some weeds but its usually on the very top, not coming from the bottom. So I don't think weed cloth would really work. Its up to you but I don't think its worth the money or time. In the future if you want to turn those beds down deep it could be an issue. My beds are 8'x4'x2' Instead of weed barrier I would spend the money on some kind of watering system or you will be out there with the hose constantly and that gets old fast. Camp Verde AZ