What are some longer-lasting alternatives to pine boards on raised beds?

Question:

I have used raised beds to make the most of my limited space in South Portland, to reduce soil disruption to protect soil health, etc. However, I am tiring of replacing the pine boards. They last me years but would love a permanent edge so all energy can go to gardening. I see folks using cement blocks, plastic, galvanized metals, all of which leach toxic materials so are not good for organic gardening. Are there any other solutions I am overlooking? I would like them to be 10-12″ deep, like the boards I use, because I like sitting on the edge to tend beds.

Answer:

Marjorie Peronto, Extension Educator, Hancock County

I have struggled with the same thing, tried many alternatives, and am happy with the following: frames built from rough-hewn hemlock or cedar 4″ x 4″s or 6″ x 6″s.  They are not cheap, but in my experience, these frames last 20 years before needing to be replaced. You can extend the life of your frames by stapling house wrap to the inside before adding your soil, which acts as a moisture barrier. The lumber is stacked and held in place with rebar that is sunk 24″ into the ground. I have also used very large rocks to terrace raised beds on a slope. The rocks came from the soil where I was building the garden.