10 year old treated wood okay for square foot gardening?

[jenkuh]

My dad wants to plant tomato plants and asked me if I'd eat them (because he knows I'm a stickler about organic and no-chemicals) if they were grown in a box that had really old, but had been treated wood? I had no idea! haha

[Carley]

The concern is with arsnic. We have tons of treated wood leftover from a deck / garage we demolished & have sought to use it in everything we build.

I did a lot of research... really I think it's more of a subjective decision. Yes, the arsenic will leach. You don't know how much, you don't know if it will be more/less than "normal" arsenic levels in your particular soil, you don't know if they'll be concerning levels.

They've taken it out of playgrounds thinking it could leach into children's skin with a lot of rubbing & contact.

We priced out 2x4's & cedar is at a historically low price. We ended up buying some 2x4s for the raised bed frames for cheap, but used the treated wood for the chicken coop, the supports for raised lettuce trays & workbench stuff.

There's a lot of information out there, but really... it's subjective. You have to figure that people used treated wood for a long time before they switched treatments. I don't know how many of them used it for growing vegetables, but people seem to have gotten along allright.

[lightheart]

I have a few thoughts, if it's old it has leeched a bunch already, was it sitting there leeching? the ground soaked up the leechy stuff,, if it was someplace else and moved to it's current location, the old ground sucked up the leech and you are looking at using halfway already leeched wood.

The other thought I have is that some of the chemicals used in years past have been banned from being used today.

On a personal level I wouldn't seek out to plant my veggies in treated wood, if someone offered me veggies from pressure treated wood boxes, I'd eat them, I'd let my kids eat them. I think growing local and growing for yourself, your friends and family trumps commercial farming anyday.