A gardener wrote in this week:
“Hi there – I SO enjoy your newsletters and info! I have a question – we
are making containers to grow vegetables. At first my dad thought
pressure treated because it will last longer on the island where we live –
but I said no way! They use pesticides to treat the wood and that
defeats the whole purpose!! Do you have any suggestions? Would cedar be
good? Do you know anyplace that has pre-fab ones? Also – what should we
use for soil and fertilizer? I want our veggies to be organic. Thanks
so much! jen”
You’re absolutely right to insist on using materials other than pressure treated lumber. It’s treated with poison to kill rodents and burrowing insects. You definitely don’t want that near your food, because it does leach into the soil. That said, there are a lot of options.
Douglas Fir is the least expensive and most readily available. If you use 2″ thick boards it will last you between 10-15 years in moderate climates.
Cedar is much more durable than Douglas Fir, but more expensive. It is usually sold by the board foot, which can mean that it’s 5x as expensive as other woods. You can count on it lasting 15 years +.
Redwood is another option, though I rarely ever talk about it. Even though the redwood forests are being regulated for sustainability, I still haven’t quite let go of the idea of not using redwood. If you do choose to go for it, it lasts a long time, and looks lovely in the garden. Just make sure you look for a little sticker that shows that the wood has been certified “sustainably harvested” by FSC, the Forest Stewardship Council.
Alternative materials – I invite you to read a previous post about raised beds that has an abundance of information about Trex and other alternative lumbers. Raised Beds – Part 1- Materials.
You’ll also find several photo links to some prefab raised beds that you can buy online. Saves a lot of labor, but usually costs a bit more than building them yourself.
Thanks for writing in. I hope this helps. Keep us posted on your progress.