I've got a base built for my greenhouse on pressure treated lumber. This greenhouse sits atop of my exising vegetable garden. I've heard that the chemicals from the pressure treatment can leech into the earth. Will this harm my veGies that I grow in the greenhouse?
HELP!!!

All you ever wanted to read about it...

I think your risk is minimal but you might want to plant your stuff away from the wood a bit just to feel safer about it.

"Rufus Chaney at the USDA agrees with Bourquin about food safety. "There's no evidence that food safety is impaired by growing vegetables around CCA-treated wood." According to Chaney, high levels of inorganic arsenic in soil will kill a plant before there's enough arsenic in the plant itself for you to consider not eating it. Far more important is the risk of potential transfer of arsenic to skin and mouths, particularly for children, whose small bodies don't tolerate arsenic as well as ours do. Chaney points out that persistent leaching, however small, means that arsenic is continually coming to the surface of the wood, where it can easily be transferred to us or our children when we touch the wood. "There's just no way around it," Chaney says. "For me, this is the overriding reason not to use CCA.""

Personally I would not use pressure treated wood in my garden. I don't care what the experts say about plant absorption of chemicals and the amount of toxic chemicals you would consume in the end. This is my personal belief that no chemical (man made) is safe or reacts well with Mother Nature. My garden is organic, no chemicals are used in the process.

Pressure treated lumber is treated with chromated copper arsenate. That means it has arsenic in it. Everybody knows that arsenic is a poison.

When handling and using Pressure treated lumber in construction you are supposed to wear gloves and face mask when sawing so as to not inhale the dust or to get a splinter of the arsenic soaked wood in your skin. These warnings are posted on the wood labels.

Plants do absorb things from the soil. For instance when pennies where made from copper people would throw a few pennies into the hole when planting a hydrangea to turn the flowers blue. Presently there is research being done to find out which plants absorb which chemicals so plants can be used to clean contaminated land. For example clovers absorb car oils.

How much arsenic could possibly leech into the soil and then be absorbed by your prized tomatoes? I do not know. I do not look at it that way, instead I look at it this way: How much arsenic do I want to have in my diet?

My answer is none. So even the Federal guidelines for “safe” amounts of contamination with arsenic is too much in my books.

Encapsulate the lumber

One solution to the issue is to encapsulate the material to prevent the chemicals from leaching or being rubbed off by you or your pets. Sounds a bit expensive to me, but if you are in agreement with David then I think it's a good solution.

We've just returned from the lumber store - and I see your new post ami! Thank you too, David.

GRRRRRR! We bought cedar to replace the treated lumber ESPECIALLY after reading the warning (at the store) about not using pressure treated wood next to aluminum! My greenhouse has an aluminum frame. Apparently the chemicals in these two products don't agree and in time the aluminum would crumble away.

It's just NOT my week!

I want to add a bit to this.... We took the pressure treated lumber out and on the side where it made contact with the aluminum, it had white chalky stuff all over it--- aluminumoxide! I CANNOT BELIEVE that it reacts so quickly! It's only been less than one week!

I'm really glad that we accidentally read that sign at the lumber store!

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