Posted: 12/03/2014 at 20:16
Hi Melanie, just last week I made a raised bed from scaffolding boards available free at Epping forest in east London, through free cycle You can pick up a lot of wood free if it is not too far for you. I made another from pallets also picked up free from some builders. Just don't use wood that has been treated with chemicals if you are planning to grow organic vegetables.
I didn't bother lining the larger bed _just dug over and topped with compost and fertiliser. Stakes in the corners will be useful, like Busy Bee suggested, to put up netting or cloches.