<http://schema.org/alternativeHeadline>
"Want to know which plants will grow well in your garden? Follow the map, which is based on the average lowest winter temperature in your area."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/your-home/organic-farming-gardening/stories/how-to-use-the-usdas-planting-zone-map>