I use it all the time..Purists will tell you no don't use it.....You have to do your own research and decide for yourself.

Cedar wood is great,
if you can afford it (it is pricy).

You'll probably have less trouble with insects getting to an above-ground box, though.
So you might be able to get away with untreated pine.

DH built my raised bed garden from untreated pine. That was 3 years ago and they are still going strong. We plan to surround the raised beds with cinder blocks when they start their decline. Personally I would not use treated lumber around food crops but that is a personal decision. The chemicals used may or may not be safe for human consumption. It is recommended to wear gloves when working with all treated lumber and to wear face mask when sawing so as not to breathe the dust.

Cheers,
DL

Just use untreated pine, and coat the wood with boiled linseed oil. It wont last forever, but you will feel better eating the food from your garden - knowing that no harmful chemicals leeched into your garden beds. My beds lasted for about 5-6 years before I rebuilt them.

Tim

We used cedar but it was expensive even with the 66% discount (the contractor messed up the bid so we only paid for 1 box even though we had 3 built). My sister had an almost non existent budget so she used cinder blocks that she got really cheaply from a company that builds schools and commercial buildings and what not (they sell the extra they have from jobs very cheap). And the ones she got are nice, not just the normal white ones. Just some ideas.

I started using fiberglass bathtub liners with a few holes drilled in the bottom for drainage this year. Just the right depth and easy to maneuver around and reach across. I set them on cinder blocks with 2x6s on the blocks for added support. I don't know how they will hold up but they were free.

I loved my raised beds when I had them but after we moved DH was too busy with house renovations to do garden jobs. Raised beds look great but perhaps you don't have to have contained beds. I built lasagna style beds on top of old field sod. The beds are taller than surrounding lawn. Weeds tend to creep into them a big but I've put down wet newspapers covered with grass clippings for paths. I did get a lot of creeping weedy stuff in one bed so early this spring I put down black plastic for a few weeks. The weeds were smothered and easy to remove.

Were you planning to put a path in the 10x12 bed? I've decided it's much easier not to walk at all in the beds. I tried boards the first year but wasn't happy with them. This year I dug a trench for paths and put down the newspaper and grass clippings. I can push my finger into the soil it is so nice and loose.

Besides others already mentioned, this may also depends on your weather, irrigation, etc. My first two raised beds were built with untreated wood. With drip irrigation and dry summer, they lasted five years.

If you want something more permanent, one I really like is the cinder blocks. Unfortunately, it's not feasible on my steep hills. If you're on flat ground, that could be another option. John had put up a lot of nice pictures of his cinder block raised beds.

As defrost mentioned, you really don't want to walk through your beds. It would be better to build them no more than 4' wide (so you can reach in 2' from each side) and have paths 4' wide (to maneuver a wheelbarrow, turn it and be able to dump it without stepping into the next bed)
All this is learned through trial and a LOT of error! LOL
Garden on! NT