Local Action for a Sustainable Tomorrow

Raised Garden Beds
http://www.thecompostbin.com/2006/03/raised-garden-beds.html
3/14/2006

Every year I expand my vegetable garden and build more raised beds. You can never grow enough tomatoes! Five years ago I had started with two 4’ x 8’ raised beds that I made from cedar 2x6s and 4x4s. Last season I added three 3’ x 10’ beds and that brought me up to over 230 square feet of planting area.

Making a raised bed is a simple bit of carpentry that anyone should be able to do. The easiest way to buy some 2x12 lumber and screw them together in the shape of a rectangle. You can make them as long as you like but you should limit the width to 3 or 4 feet so you can easily reach in the bed to plant seeds, pull weeds or to harvest crops.

The next question you’re probably asking is what kind of wood do I use to build raised beds. The whole pressure treated vs. non issue is a complicated one. Does pressure treated wood leach chemicals into the soil? Well the answers are yes and maybe.

The old pressure treated lumber (CCA) is preserved with a process that uses arsenic. Obviously you don’t want arsenic anywhere near something you’re going to eat even in the small amounts that might be present in a raised bed vegetable garden. CCA wood isn’t too readily available anymore so you probably don’t have to worry about coming across it. The new improved pressure treated wood (ACQ) replace CCA pressure treated wood a few years ago. The lumber industry says it safer to handle and use but guess what? It eats through normal galvanized screws and fasteners. You have to use stainless steel screws with CCA wood. Hmmm, I’m not an expert with lumber or chemicals but that sounds fishy to me. I think I’ll avoid it until some long term studies are done.

The first four raised beds I built were from cedar. But cedar is really expensive and my wife wanted to kill me for spending $300 on wood that I was going to leave in the yard. My latest raised beds are built from regular non-pressure treated lumber that is rotting away in my garden as we speak. If I get about 5 years of use from it, that’s good enough for me and my veggies.