wife would like a raised garden bed and my question is do i use treated lumber for edge or plain pine also do i need a barrier for bottom. thanks k

 

Treated lumber and no bottom barrier.

 

Treated lumber and best to go with that rated for ground contact

 

I agree that treated lumber will last longer although I read somewhere that there are issues with the chemicals in the wood leaching out into the dirt and making it's way into the vegetables

I have no idea if this is a valid concern or just a bunch of bull but thought I'd pass it along just in case.

 

My wife had the same concern so I lined the inside with galvanized steel like you would use for roof flashing.

 

I have had a raised bed with treated lumber and no barrier on the bottom for about 10 years.

I have seen no effects of the treated lumber (unless you count my 6th finger). I can actually type faster now

 

LOL!

There has been studies done on treated lumber leaching into the soil of a raised bed and they have found that only the soil right next to the lumber shows any traces of chemicals. However even those traces are so small there is no cause for concern. Search google and I'm sure you will find some.

 

I suspect the creosote in old railroad ties would be worse than the chemicals in PT wood.

 

I have these raised garden beds made out of poly, which is good for the soil and everything esle on earth. They work great hold in water keeps the soil cool on hot days and warm on cold days. Best of all they DO NOT add anything to the soil....

 

I was informed by a home supply person never to use pressure treated lumbar for a garden bed because of concern regarding chemical leaching. At least if one is growing vegetables to eat.
New questions: I am interested in building raised garden beds. Though cedar seems more attractive, I thought I might use cinder blocks, which are more economical. However they are rather unattractive, so I thought I might paint them, e.g. brown or green to appear nicer. Any idea how long paint in an outside environment would last & if this seems a good idea in general? Thanks! - Alan

 

Aremde,

Welcome to the forums.

You're concerned about the chemicals of PT lumber leaching into your veggie bed, so you're going to paint the blocks?? I'd be a bit concerned about finding paint chips in my salad.

Rather than cinder blocks, why not use the interlocking wall blocks? Split faced, several colors other than concrete gray available, and they look good. No need to paint them. They're about $1.50 each -- roughly the same as cinder blocks, and no footing or mortar involved.

 

I assume the blocks would only be painted on the exterior side - the bed side would be covered with dirt, right?

Generally paint holds up well on block but when the backside isn't sealed and moisture is allowed to travel thru the block [like with a retaining wall] the moisture will kill the paint job, sooner or later

I like Lefty's suggestion

 

I built a new 6' X 16' raised bed this spring using some left over Trex deck boards that I had used as forms for a curved walkway.

I wonder how long it will be before some self appointed environmental watchdog group will declare Trex a threat to the planet and the human race.

 

As you can see, there are lots of ways to construct raised beds. We've used cedar 2X8s for over 20 years now. They last for 5 or 6 or even 7 years. I know there's some difference of opinions about using PT wood, but with the cedar we're sure to be safe.

Never used bottoms (I assume you're talking wire mesh of some sort?) and only rarely had problems with burrowing critters.

Just my 2 cents.