DIY Home Improvement Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
135 Posts
Discussion Starter #1
Hello I just build a 4' x 12' raised garden bed using 4" x 4" AC2 treated lumber.

I've read that it could be concerning to use treated lumber in vegetable garden beds like this. One solution I've read about is putting 6mil plastic around the inside of the bed to minimize leaching of the treated chemicals. Is this needed or any other suggestions?
 

Attachments

·
Civil Engineer
Joined
·
5,832 Posts
Unfortunately the information provided by Menards and the manufacturer fails to indicate what chemicals were used to preserve the wood. The literature claims that the wood is suitable for ground contact, and has been treated at approximately twice the "normal" level for AC treatment. Presumably the wood was treated with Alkaline Copper (the AC), however I cannot confirm this from the literature. Could be a proprietary treatment.

I do not know how much chemical is likely to leach from the wood, the literature does not discuss leaching. The literature does state that the product should not be used in direct or indirect contact with groundwater, so if you have well, there may be some concern. There is always some risk using undocumented chemical compounds in an agricultural setting, you may want to write to the manufacturer to see what they have to say.
 

·
A Little Of Everything
Joined
·
2,398 Posts
I don't know what they now use in green treat lumber, but arsenic hasn't not been used for years.

I guess I'd encourage you to continue to research it further.
 

·
Registered
Joined
·
10,306 Posts
I have two small raised beds made with PT 2x6s. It's the standard brown waffle-faced PT stuff I got at Big Orange store.

Everything in there grows like crazy, especially weeds.

So my experience is, the PT may actually help things grow. It certainly isn't hurting.

But these are beds for flowers and a few shrubs. Don't know if it's "foodsafe."
.
.
 

·
Registered
Joined
·
1,106 Posts
You can be worry free if you know whats in PT wood these days- no more chromium or arsenic. Either copper or boron (boric acid/borates). relatively harmless. lets stop the fear mongering.

Also, plastic should not "leach out" any toxic chemical. It is relatively "inert".
 

·
Registered
Joined
·
4,733 Posts
Years ago I built mine from CCA treated wood. Thirty years later we all are all still alive and healthy.

I would not lose any sleep over it.
 
  • Like
Reactions: ZZZZZ

·
Registered
Joined
·
871 Posts
Years ago I built mine from CCA treated wood. Thirty years later we all are all still alive and healthy...
My veg garden consists of several PT-framed beds, 4'x8' up to 4'x32'. We've been eating the produce for ~25 yrs -- just picked collards and mustard for tonight's dinner, lettuce for salad.
 

·
Registered
Joined
·
9 Posts
From what I have read the main reason is to prevent weeds. I am not good enough to know how that works, but I guess my point was if it is recommended anyway you might as well do it and be covered just in case.
 

·
Registered
Joined
·
871 Posts
From what I have read the main reason is to prevent weeds...
One advantage of raised beds is easier maintenance and weeding. However, I'm inherently lazy so I rely more on mulching around the plants to control weeds (typically with pine straw, since I can just rake it up from my front yard),
 
1 - 14 of 14 Posts
Top