Wood for grow boxes

Begs the question 'what do they use' to preserve the wood? Nothing is used that would be harmful to vegetable plants? Dunno 'bout that one..

supposedly the new treated lumber is safe for indoors construction but not safe in making cutting boards with, so if it shouldn't be in your food, it probably shouldn't be in plants' food

the new treated lumber that is supposedly safe has some kind of copper chemical in it = is copper bad? you decide (the people who sell it will say it is safe, but it may not be, puffery is allowed in sales)

the cedar and redwood you mention might be okay for grow boxes

I'd use the "Plastic decking" that's made of recycled milk jugs as it will outlast all of us combined and contains no preservatives. Info:

I'm using plain pine logs from thinning my woods. If I have to replace them every 5 years, so what. Let em rot - I gotta get rid of the somehow.

Don't use treated lumber of any kind!!!!! The 'safe' stuff is only a relative term and you don't want to hear in 10 years that there's a problem. DDT, CCA lumber and tobacco were once thought safe, too!

ACQ (Alkaline Quaternary Copper) is the replacement for CCA (Chrome Copper Arsenate). It is said to be safer than CCA. That's not saying much, kinda like a Rattlesnake is safer than a Black Mumba! It's not rated for food use and only the highest ACQ level is rated for ground contact. The Quat is a fungicide whichcan't be good for seedlings.

The only untreated wood I know of that's rated for direct contact is ipe. I don't know if it contains natural oils that might be toxic. White oak (NOT red oak) will last many years wet and there's nothing toxic in it. Stay away from nut family woods (hickory, walnut, etc).

You plant a garden so that you're sure the food is good. Don't take a chance!

Philip

Good day Russell, unsure what type of 'grow boxes' you wish to have or their size. If these boxes will be more like raised beds, then I would suggest that you look at stone. The allen block, diamond block type. These will cost a bit more in the begining, but they will pay for themselves in the long run for sure.

If your thinking smaller, then I would recommend trex composite. Trex will again cost a bit more, but will last 15+ years in the ground with no problems. It's paintable and screw'able.