Winter lingered on as long as it could, but spring is in full force, and so are our summer gardens. I have seen the potting soil flying off the shelves of home garden departments, as well as the containers and the mulch. Here at the Extension Office we’ve answered several questions this week on raised-bed gardens and the use of treated wood in those gardens.
I believe what most gardeners are worried about is chromated copper arsenate (CCA). The majority of the wood sold for outdoor use in the U.S. between 1975 and 2003 was treated with CCA. Studies have shown that CCA-treated lumber can leach chromium, copper and arsenic into the surrounding soil. But the migration of these elements appears to be limited to a few centimeters adjacent to the lumber and research has not clearly shown a long-term negative impact upon plants.