Garden timbers available at most home and garden centers are made of core wood from trees that have been processed into plywood and are rarely hazardous to use in your garden. It is advisable to avoid wood treated with CCA (Chromated Copper Arsenate) for landscape use, as a safety measure. These residential products generally consist of garden timbers, porch and patio decks, picnic tables, children's play structures, fences, and walkway materials. Raised beds for flower and vegetable gardens can be created with cinder blocks, bricks, sandbags, or treated logs.
Natural rot-resistant wood such as black lobster, red mulberry, osage orange, Pacific yew, eastern or western red cedar, black cherry, honey lobster, white oak, Douglas fir, redwood is best for making raised garden beds. If you have already done landscaping work with pressure treated wood, it shouldn't be a problem for landscaping plants and flowers. If you are worried about using wood treated on a raised bed of vegetables, regularly perform a heavy metal soil test in addition to a standard soil test. Cover your bed with untreated wooden planks to make a flat surface to sit on and avoid contact with wood.
Liming at a pH of 6.5 according to a home garden soil test will reduce some of the metal uptake by plants. In May 2020, Fine Gardening committed to planning and planting a garden for Karen, an emergency department nurse.