Try a paraffin wax-based preservative. Probably you could make your own
by dissolving a box of canning wax into a gallon of mineral spirits.

Jeremy Elkins wrote:

I did some research on this a while back after I put treated wood around my
garden. Basically the arsenic that is used to treat the wood does leach out
into the soil but it's a real small amount that isn't likely to hurt you.
It also doesn't go very far like maybe 12 inches - of course if you till it
and move the soil around then that becomes irrelevant. The vegtables can
and will take in the arsenic - but again it's real small amounts. If you
are going to use the treated wood (which I wouldn't ever again) you should
put up a plastic liner between the soil and the wood. Stone, plastic,
non-tread wood, etc. are much better choices.

"Andy N" wrote in message
news:gki_9.93150$rM2.45429@rwcrnsc53..
I am making a new garden and was planning to put treated 4X4 lumber around
the perimeter. Someone mentioned not to use it because the chemical will
leach into the soil and contaminate the vegetables which may cause cancer.
I
would appreciate your opinions on this matter. Thanks