Raised bed construction material

[NwMtGardener]

Hey jennifer, we built our raised bed so deep that i didnt worry about putting anything down underneath for the weeds. I am NOT a fan of garden fabric (my experience: doesnt work, creates more issues). So, i think we put about 18" of dirt into our raised bed, and have continued to add compost since building it um, 5 years ago? The only weed that eventually came up thru that much dirt was wild morning glory, that $?$@ stuff! our whole neighborhood is just engulfed with it, and its like indestructible, so it was pretty much inevitable.

If you're only doing one layer of concrete blocks tho... I guess i would do one or several of these things, since that's probably not going to be deep enough to keep grass and other things from coming up through. I would 1. Dig and remove all vegetation from your site. 2. Spray with roundup to kill all vegetation (i know, evil! But i've done it :/ ) 3. Cover with thick black/dark tarps, pond liner, carpet, something that will eventually smother everything there. Took a few weeks for my grass to die, even with thick pond liner down. 4. Lay down cardboard, thick and overlapping, after one of the above steps, to make sure you got all the growies! Then add your dirt, and you're still going to have to weed! but it will help a ton to do good bed prep!

P.s. The pond liner or tarps do not stay in the bed, thats just to kill off the crap!

 

[gettinaclue]

We covered the bottome of ours with welded wire.

 

[Jennifer]

Wow Heather, that's lots of work!!

This year I was lucky with the spot I chose--most of the grass was already dead and had been for years. It was where my fiance's brother stored his Scamp Camper trailer, and he sold it in February, and so this area had years of no sunlight (although my dog did like to "fertilize" under there during winter with snow ). Since I got the garden going early in late April, nothing had a chance to try and grow there, and surprisingly, the soil is quite fertile. With the garden fabric and heavy mulching, I haven't had an issue with weeds, except for the ones poking their way through the chicken wire on the outside.

But if I want to raise this area or expand it, there's grass all around it, so I am thinking for the future. I saw a program where someone had pretty tall raised beds, about 2 1/2 feet give or take. They used garden fabric nailed/screwed to the tops of the beds and filled that in with their own soil and compost to control it, and that looked like something I might consider. The beds were tall and large enough (and they didn't over do it) so that each plant had enough room to grow and for its roots.

Even if I did choose concrete blocks (I love the idea of planting things in the holes) it would be great to see photos of what others did and how tall they raised their beds.