Sure, I put down cardboard right on top of the sod. You can also raise your beds. There are lots of options. I suspect that you will find alot of options. The only problem that I have realized with the boxes is that the grass will come inside the boxes eventually via seed unless you get rid of all the grass in your yard. Usually, it's just a few stragglers though and perfectly easy to weed.

Thanks. I've got so discouraged with gardening here because weeds are just insane. I completely lost one flower bed to red fescue, another to creeping charlie, and my vegetable garden to lambs quarter and other unknown weeds. I'm interested in this raised gardening, but I'm not sure how it is for weeds and if you can still cut down weeds alot without removing all the sod.

My beds have landscaper cloth bottoms and are directly over sod. I didn't kill the sod or remove it before putting down the beds. So far, nothing has crept through.

Professional grade landscaping fabric will work just fine on top of your sod...get the good stuff, though.

EG