I've just made 2 raised beds from larch that I got from a local saw mill. Its was treated though with dark creosote (smells like). I saw somewhere that I should line the inside of the beds before filling, with plastic bags (saved from compost). What's the general consensus?
I have 2 raised beds, one 2.5m x 1m for veg and the other 2m x 1m (split level) for herbs and maybe some strawberries.
It's up to you really. Lining the insides will redcue the amount of moisture the wood can absorb from the soil so it will alst longer and will also prevent any chemiclas leaching into the soil. Very easy to attach with a staple gun.
Better safe than sorry. The general advice seems to be to line the sides anyway to prolong the life of the wood.
I've lined mine with heavy duty polythene sheeting - quite cheap from the ironmongers. I also lined the base with permeable membrane to stop the compost washing out of the bottom - it was a tip from someone on here.
My beds are only a decking board deep so lining the bottom would stop me from growing deep rooted crops in those beds. An allotment member was plagued by mares tail on a new plot and completely lined his new beds after digging out what he could of the weed. It was alright for a bit but some of the mares tail eventually showed up but it was certainly better than it had been and manageable.
I have 3 raised beds - about to have a fourth. I put down large pieces of thick cardboard n the base - apparently bike shops are a good source and just painted the sides. I have since found that they are best with heavy duty polythene lining the sides so will do that with the next one. I have a big heavy cardboard box ready and waiting for the base
one is 30cm deep
the other is 45cm and 30 cm
I will line them both
The soil below is quite good, if a little clay and mostly had turf over it for long time.
Mine is clayey and laid to turf and I just put the cardboard on the turf. I'm sure some on this forum will say NO, but it has worked for me. My beds are 30cm high