Best way to treat wood

[FionaH]

Yeah I know this is yet another raised bed question but bear with me please

Mr H has access to some untreated planks, very cheap. I am dead excited as you can imagine Can anyone suggest the best thing to treat them with to slow the rotting process down without poisoning whatever I grow?

Mr H wants to use creasote which I am pretty sure will kill everything!

Thanks in advance

Fi

[SarzWix]

You can't use creosote for anything any more, I'm pretty sure it's not even on sale due to being carcinogenic There is a substitute, but I wouldn't want it on my veg beds...
Garden Organic say linseed oil is quite useful, although it isn't as long lasting. Or you can get water based wood preservatives.
My beds are made with untreated wood, it might not last forever, but no nasties

Alternatively, if the sides are high enough, you could line them with plastic? Even cut up compost bag would give a bit of protection.

[kitchengardner]

You can't use creosote for anything any more, I'm pretty sure it's not even on sale due to being carcinogenic There is a substitute, but I wouldn't want it on my veg beds...
Garden Organic say linseed oil is quite useful, although it isn't as long lasting. Or you can get water based wood preservatives.
My beds are made with untreated wood, it might not last forever, but no nasties

Alternatively, if the sides are high enough, you could line them with plastic? Even cut up compost bag would give a bit of protection.

If you slightly char the wood (a blow torch is good for this) before applying warmed linseed oil it absorbs much better. Allow to dry thoroughly and then apply a second coat (no charring or heating this time). This should make even soft wood last 10 years or so. The plastic lining does help to slow the onset of rot and also helps the beds to retain water

Hope this helps

Regards

Kitchen Gardener