Pressure Treated wood for Vegetable Garden?

[Scooby074]

I just had the dried out and cracking cedar siding pulled off the south side of my house and replaced with HardiPlank siding. I also had a new bathroom addition to my house under a raised deck. To facilitate putting on the roof on the addition, we had to take up approximately 80 sf of treated lumber on my deck and then replace it with new planks. When all the additions/renovations were done, I waited for a good non-windy day just after a rainstorm and called my county sheriff to let them know I was burning. When there is no burn ban in place, you do not have to call, but they request you call the sheriff and give your name and location if you have a large amount of burning to do. The sheriff then knows it is you in case someone spots the smoke and reports a fire. People are rightfully paranoid around here lately with the wildfires west of here. Anyhow, the sheriff asked what I was burning and I told him construction debris, mostly cedar siding, cardboard, and wafer board and the old deck materials. "You can't burn treated lumber!" was his instant response. Oops! :ashamed: So, I told him I would separate out the treated lumber and not burn it. Sheesh! This was the first time I had heard of such a restriction. I used my backhoe to turn over the pile of debris until I had picked all the deck lumber out and stacked it to the side of the bonfire. Now, I guess I'll just bury the treated lumber. If you can use it on decks and other ground contact structures, surely burying it is a viable disposal method, but I ain't gonna call and ask for permission.:confused3:

I think the issue with burning PT is it releases the chemicals from their bond to the wood fibers. It becomes an inhalation hazard.

grnspot110: great garden. Having a greenhouse sure would be nice. Im figuring if i do a raised bed, i can make arches out of PVC and cover with poly... to make a poor mans greenhouse.

 

[KennyG]

There have been a number of studies, especially from Michigan State University, that show that the chemicals in treated lumber only migrate a fraction of inch in soil. It seems that treated lumber can be successfully used in gardens with an understanding of the material. In the first place, there are two types of PT. The old CCA had arsenic. The newer ACQ is more predominately copper treated and doesn't leach out very easily. However, if you have sawdust from cutting on the lumber, it will get in the soil very quickly, so you need to clean it before using it. As noted above, burning is bad because it liberates chemicals that would otherwise never cause human exposure.

I wouldn't hesitate to use treated lumber, but my wife is very concerned about these things, so I built the raised beds from the synthetic decking material. Cost was a little less than cedar would have been and I think they may last longer.

 

[Scooby074]

There have been a number of studies, especially from Michigan State University, that show that the chemicals in treated lumber only migrate a fraction of inch in soil. It seems that treated lumber can be successfully used in gardens with an understanding of the material. In the first place, there are two types of PT. The old CCA had arsenic. The newer ACQ is more predominately copper treated and doesn't leach out very easily. However, if you have sawdust from cutting on the lumber, it will get in the soil very quickly, so you need to clean it before using it. As noted above, burning is bad because it liberates chemicals that would otherwise never cause human exposure.

I wouldn't hesitate to use treated lumber, but my wife is very concerned about these things, so I built the raised beds from the synthetic decking material. Cost was a little less than cedar would have been and I think they may last longer.

I thought about Trex too. As a permanent solution (plastic never rots) but its $60 for 1x6x12' piece:confused2: Building a 4'x12'x16"high box out of Trex will be far too costly for me.

 

[dmccarty]

Years ago in the days off CCA I read up on PT wood for use in raised beds and because a house kit we were thinking of buying used 6x6 CCA PT timbers.

One of the reports I read was from the EPA. It did not impress me at all. Full of might and could words instead of will and does.

CCA would leach into the soil but it would not migrate very far. Something like an inch or so. Getting sick from CCA was only realistically possible if you burned it and breathed the smoke, inhaled saw dust, or chewed on a piece of PT wood. Since I was not going to burn the PT nor chew on it I felt it was safe enough to grow veggies. I was careful in cutting.

Later,
Dan

 

[groundcover]

I used PT for garden beds but I wouldn't burn it , here it is against the law not only due to toxic smoke but the ash from the older cca PT is "hot" too, have heard stories of animals getting into the ash and passing away.

 

[clemsonfor]

I was a wood products minor in college. Those were the days of the swap from cca to Acq. My professor said that a grown man would have needed to eat about 1lb of treated boads to get sick, im not sure who can or would eat that much decking material before they realized what they were doing?:confused2: I would not hesitate to do it but some think i dont care and use the worst stuff imaginible.

Last year i said something about using Glyphosate (roundup) in my garden before planting and around the sides and i was jumped on like i was spraying the most cancer causing product imaginible on my vegtables and then consuming them. If you read the LABLE (the first thing they teach you to do when you get your pesticide/herbicide licence, which i have) it says on there not known to case cancer in animals or humans. Now i know we have no idea what will happen in the long run, but roundup has been around for id venture to say 20+ years. And if this was the case do they eat corn or soybeans or any mass produced crop that is notill planted, how do you think all that grass and weeds die before they do that hippie notill method anyway. Then there is roundup ready corn and soybeans that they actually spray roundup over as they are growing to kill the grass and the crop is genetically modified to not be affected. Ok I will get off my soapbox and come back from this tangent.

 

[studor]

The PT should not be a problem but if you are at all worried about it just use 6 mil plastic to line the bed sides -- then you only have to worry about BPA. I lined my PT formed raised tomato patch with plastic and it has lasted for over five years without maintenance -- JMHO

 

[Scooby074]

I was a wood products minor in college. Those were the days of the swap from cca to Acq. My professor said that a grown man would have needed to eat about 1lb of treated boads to get sick, im not sure who can or would eat that much decking material before they realized what they were doing?:confused2: I would not hesitate to do it but some think i dont care and use the worst stuff imaginible.

Last year i said something about using Glyphosate (roundup) in my garden before planting and around the sides and i was jumped on like i was spraying the most cancer causing product imaginible on my vegtables and then consuming them. If you read the LABLE (the first thing they teach you to do when you get your pesticide/herbicide licence, which i have) it says on there not known to case cancer in animals or humans. Now i know we have no idea what will happen in the long run, but roundup has been around for id venture to say 20+ years. And if this was the case do they eat corn or soybeans or any mass produced crop that is notill planted, how do you think all that grass and weeds die before they do that hippie notill method anyway. Then there is roundup ready corn and soybeans that they actually spray roundup over as they are growing to kill the grass and the crop is genetically modified to not be affected. Ok I will get off my soapbox and come back from this tangent.

Glyphosphate isnt so bad... If you drink enough of it, worse that happens is you'll pee bubbles:thumbsup:

 

[roygage]

I 'd like to build a raised garden this summer for veggies.

Any opinions on using new ACQ type PT for the frame? I know Cedar would be preferred, but $$$.

Theres a bit of mass hysteria out there re: PT wood but how much is fact based? Ive seen opinions ranging from "you can eat it", "Wont kill the fish in your fish tank" to "OMG, your going to kill your family". ACQ companies of course say there's no risk. Creosote timbers are out though... they just leach far too much to be safe.

Dont want to use spruce, as i dont want to redo in a few years. I might be able to get some rough Hemlock that has good rot resistance but not sure if its available currently and at what cost.

Opinions?

Sevral years ago I made a raised bed for my wife out of old rail ties. Worked good.

If you are concerned about leaching though how about making it out of those interlocking landscaping blocks they use for the retaining walls. Maybe dig the first level down into the dirt half the depth of the block and then one more row on top of that.

 

[KennyG]

I thought about Trex too. As a permanent solution (plastic never rots) but its $60 for 1x6x12' piece:confused2: Building a 4'x12'x16"high box out of Trex will be far too costly for me.

The box stores have a lower cost alternative that cuts the price in half but it still adds up. I used plastic 1 x 8 trim boards and matching 1 x 2 stakes. Still, if it had just been me, I would have used PT.