I researched it and the new treatments are supposedly safe. My brother's used treated wood for a decade and it still looks great. I'm not worried about my 16.5 inch treated raised beds, and they'll last a decade or more just like my brother's. It cost me over $600 for my 130 SF of raised beds made with 3 2x6 high beds. Cedar is much more expensive here in the Seattle area. Though I found Douglas Fir is really cheap and holds up well untreated.

Here is a link that might be useful: Sinfonian's garden experience!

I wonder why more people don't consider poured concrete. A 4 by 4ft bed, 16" high is a special case for concrete construction where a footer is not required. Material cost would be about $50, and form cost for the first one another 20 to $25.

The issue many worried about with treated wood was arsenic, but at least in the US arsenic is no longer used.

The new stuff is supposedly safe to use, but there seems to be an attitude of 'I don't want it to be me that is the test subject for the new stuff' ;-)

It really is a personal decision and there is information out there about what is used to preserve the wood and it's ability to leach into the soil etc.

I just went ahead and built my boxes out of cedar. It wasn't that much more than treated lumber at the time, but this is going to vary from area to area and time to time.

I found the 2x8 lumber in lengths over 10' to be the best bang for the buck, but again, this will vary.

Mel Bartholomew wrote a book on square foot gardening and i like a quote he used on the best wood. The best kind is free. I suggest you look around for free lumber and make a bed or two out of that before spending a bunch of money on cedar. I can't imagine spending $600 to build a bunch of garden beds.

I built mine with (relatively) inexpensive pine lumber. They were great the first year. At the moment they are snowed under, so I can't say what their current condition is. I tend to agree with what Mel says in the book about lowest possible cost of lumber, though. I expect several years of service out of these beds, and can replace them several times for the cost of cedar or redwood here in Maine.

I may treat the next box(es) I build with a coat of linseed oil and see if that extends their lifespan, but I can't see myself investing in expensive wood, especially when, at least as it seems to me, the money is better spent on good ingredients for your soil (Mel's mix or otherwise).

Its true about the new quimical used in treated wood to be safe. As the matter of fact, it is not new. It is fairly new compare to other products but this new quimical has been used around 10-15 years.

I actually did a light research on the local companies that supply HD treated wood, and they claim is totally safe. The guy at HD said that most of the people buy the treated wood for garden beds.

So that is why i decided to go with treated wood, cheap, safe and easy to built. it cost me about $42 bucks for six 2x6 that i used to built two 8x4 beds.

As a safety, even if i know treated wood it is really safe, i will put plastic cover in the inside walls of the beds, so that the soil mix has no or very minimal contact with the quimical.

So i guess my $42 was well spent compared to some of you's pricing.

As far as the soil mix, i cannot find the vermiculite. If i have to, i will ignore it and either use perlite as replacement, or even go with straight compost or a combination of compost and peat moss.

I too wondered about this when choosing lumber. I built my first raised frame this week and went with cedar even though it was expensive. Initially it was to avoid any sort of chemicals, but after I completed it I wouldn't have it another way because it just smells and looks so good. For something that you're going to be around a lot, I think that matters at least a bit! Check out how it turned out on my blog.

Here is a link that might be useful: Hands On Blog: Less Talk, More Action

i built my beds out of lumber shorts that i purchased from totem for 2 dollars a piece, it is well worth going to places like this as they usually have lots of bargains if you ask. i managed to get hold of about 40 4ft lenghts of cedar decking cut offs and i only payed 20 dollars for a 10 ft length of 4x4 post to make my corners.

i havnt filled them yet but im in calgary canada so im waiting for the snow to go

I purchased a plastic, composite wood trim from Home Depot. It was 1 x 8 and costs $25.00 each. Very simple to construct and white in color. I made 9 boxes for $50.00 each. They should hold up well. The trim is intended for the exterior of homes. You can view my boxes on You Tube " Donna's Square Foot Garden". Hope this helps.

How about bricks or concrete blocks? filix

If I ever get my own property, I'm going to build hypertufa beds. Sigh, I dream...

I am building four 4 x 8 beds this weekend. I know that SFG only calls for 6" deep beds, but in the interest of saving myself the time and work in leveling the ground inside the beds, I am going to use 2 x 8" boards. I am a (hopefully soon) divorced mom with two kids under 5. Trying to level the ground inside the beds is just too much work. And quite honestly, I wouldn't even know how to begin to attempt this. I figure if I can get the boards level, I can fill them and not worry too much about the depth. The 8" boards will give me enough room so that some areas will be 8" deep and I'll get six inches in other areas without having to try to level the ground.

I am going to use the treated lumber for cost purposes. They say that the treated lumber is safe but as an added measure, I will be putting plastic against the sides to prevent chemicals getting in the beds.