material for raised beds

Does anyone have a suggestion for what to use for the sides on raised beds? Not really wanting to use pressure treated but not really wanting to replace the sides from rot every year either. I looked into the wood/resin decking but it is expensive.
Any thoughts?

stones, bricks, plastic buriable edging, metal sheeting, logs (of course they'll rot eventually),
but remember you really don't have to contain the sides..a  curved berm type raised bed actually will grow more plants than one that is contained..there are books on a type of gardening called "french intensive gardening" and they curve off the berms of the raised beds gently and plant not only the tops but the sides of the beds with the plants, thus getting another plant on each side of the space

a good place to find cheapo lumber is pallets..they are generally made of oak around here anyway..and are generally free..hard to tear apart as they are often made with heavy staples..but...they would work for making raised beds and the oak will last a little longer than a softer wood wood..

good luck

i'm redoing an entire 50 x  48 raised bed garden again this summer, and just got a start on redoing it this week..still ahven't totally decided what is going to be happening with mine either so i'll enjoy reading the answer to your post

thanks Brenda!

Black Locust will last 15+ years ground contact. I like Brenda's suggestion of sloped edges best. When i used wooden edges it was harder to take care of when i let things go and had to mow the isles.

Thanks Ronie

Black locust would be pretty hard to find in Maine though.

Karl wrote:
Thanks Ronie

Black locust would be pretty hard to find in Maine though.

If it aint on ebay - it don't exist      189 items match - from seeds to bonsai B. locust trees - even an elk caller?

I can walk outside and cut down a Black Locust and have another one shoot up before i burn the first one to heat the house.

I agree with no borders.  If you mound it really steep and then plant it, you'll be fine.

If you really want a border for some sort of aesthetic, then definitely don't use treated wood.  That's poison.  I agree with brenda's suggestions. 

Black locust will probably last a lot longer than 15 years.

one place where i do find that it is necessary to have a border or edge is when you are attempting to make a raised bed high enough to reach from a wheelchair for handicapped persons..then i would suggest a border of some sort..but if you are just raising them for the health of the garden rather than the gardener's abilities..a curved top bed is actually much better.

i have done both, but being partially handicapped i do prefer a bed with a border that is higher than the normal raised bed to make bending less of a problem ..(hip replacement)..but also possibly future wheelchair access needs for either myself or my husband..hopefully gardening will keep us from needing those wheelchairs...but better to be prepared at our age