If you have wood in your yard this is pressure treated like old railroad ties or even a deck that was built before 2004 you might have arsenic (among other toxins) in your soil. Recently, in my own yard we took out some old railroad ties and I did some research on what might be in my soil. I came across this article that talks about a plant that reduces the arsenic in your soil. If you have an older deck it might be advisable to get some of these ferns and plant them around the wood to help reduce the toxins in your soil… talk about an environmentally friendly way to fix the problem.
From MyGardenGuide.com (http://www.mygardenguide.com):
Preservatives like arsenic were used in wood timber (pressure treated lumber) used to build decks, playground equipment, and fences and are no longer used because they contaminate soil. Arsenic is however, is still used in pesticides. Exposure to arsenic is no laughing matter, especially for children and pets.
One way to remediate or remove arsenic and other heavy metals from soil is to dig it up and replace it with fresh uncontaminated soil; however, for most people this is not an option they can afford. Enter the Edenfern ™. Edenfern, which is trademarked, and as you might have guessed is a fern, was discovered in the southeastern US and identified as a new species by scientists at the University of Florida in 2001. It is hardy to USDA zone 7 and grows to a height of 2 to 4 feet. It grows best in full to part sun.
Studies indicate that this particular fern takes up arsenic in the top 6 to 12 inches of soil, accumulating the heavy metal in its leaves at a rate of 10 ppm (parts per million) of arsenic over a period of several months, a rate far higher than that of other ferns it was compared to. Fronds are harvested and disposed of in a landfill.
Learn more about Edenfern ™
Article reference: Soil Chemists Plant Ferns to Soak Up Backyard Poisons .