Pressure-treated wood OK for garden?

14 years ago

I'm going to put up lattice panels for a garden fence and the price difference between pressure-treated (cheaper) and cedar (costs lots!) is enormous. Any reason, such as poisoning, why I can't use the PT wood?

Carol

Comments (4)

tree_oracle
14 years ago
You didn't specify what type of garden.

If it's a vegetable garden then the answer is not clear. Back when PT wood was treated with arsenic compounds studies have shown that the arsenic leached into the soil but it still wasn't taken up by all vegetables. Modern PT wood is treated with a copper based compound and it isn't clear from the studies that I've seen how much of the copper leaches into the soil and how it affects the vegetables and ultimately people. These compounds don't typically leach into the soil a long distance from the wood so if your fence is at least a couple of feet away from your crops then you should be OK. Cedar doesn't have these issues of course so a piece of mind may be worth the added expense.

If this is a flower garden, then there isn't anything to worry about. Build away.
carol6ma_7ari
Original Author
14 years ago
Thanks, tree oracle. The fence section (north wall; the other 3 walls will be steel wire on steel stakes) will be tall posts and 4' high lattice panels, to grow climbing roses on. Then 4' south of this the beds for vegetableswill start; not raised beds, though. The land has a gentle slope eastward, so I'm hoping that will drain some of the copper etc., downhill parallel to the veggie beds, rather than toward them.

I could plant the beds nearest the PT fence with vegs. that are least affected. Do you know if there's any such list? (vegs. that absorb PT chemicals -- should make a good google search!)

Carol
mad_gallica (z5 Eastern NY)
14 years ago
If we are talking about the cheap, stapled lattice, roses will just tear it apart.
diggingthedirt
14 years ago
Cedar looks way better, PT doesn't ever look as good, either when new or after many years. I've had both, although we've only bought cedar for at least the last 20 years.

Personally, I wouldn't use PT, even around a flower garden, because next year I might decide to grow some tomatoes there.

And, why add something poisonous to your garden? Just cutting it to fit, if that needs to be done, adds "something bad" to your life. If cash were the problem I'd go for half cedar and half poultry wire, for this year.

It will be years before a full assessment of the effects of the chemicals used in the new PT wood is done. By then it will be in the soil of lots of gardens.