<http://schema.org/about>
"The USDA has updated its planting-zones map for the first time in 22 years, reflecting a warmer U.S. where many southern crops are expanding north."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/your-home/organic-farming-gardening/blogs/climate-change-gives-gardeners-new-options>