Pro tip: Stop using pressure treated wood for raised garden beds

I see it all the time at the hardware store. People grab PT lumber for their veggie beds because it's cheap and rot resistant. But the chemicals in that stuff leach into your soil over time. Anyone else switched to cedar or composite and noticed a difference in plant health?

3 comments

3 Comments

joelp8120h ago

I switched to untreated white oak last year and it's been a total game changer. CCA treated wood has been banned for residential use since 2003 here in Canada but people still pick up ACQ treated lumber without realizing the copper compounds aren't great for soil either. My tomato plants in the old PT bed always looked stunted compared to the ones in the oak bed. The thing nobody talks about is how pressure treated wood actually breaks down faster in acidic soil from stuff like peat moss or coffee grounds. So you end up with more chemicals leaching out over time anyway. Cedar is pricier upfront but it lasts way longer and you don't have to worry about heavy metals in your dinner.

derek_ramirez17h ago

Man that reminds me, my neighbor put in a whole bed using railroad ties once.

ellis.susan18h ago

Actually, I've read that the copper in ACQ treated wood binds pretty tightly to soil particles so it doesn't actually leach into plants all that much, the bigger concern is the sawdust from cutting it which you definitely don't want near your veg. I built my first beds with PT a few years back and my soil tests have actually come back totally fine on heavy metals, so I think a lot of it comes down to whether you're using it for the frame versus having it touch the soil directly. Still, I get why people go with cedar for peace of mind especially if you're growing root veg.