Green

A new map from the USDA has some northern gardeners hoping to grow plants that used to be considered too fragile for cold weather zones. The hardiness zone chart is about a half zone warmer than the last one issued in 1990. The USDA says the changes are not due to global warming, but to more sophisticated mapping methods. Seed sellers and buyers say that, whatever the reason, the warmer temperatures expand possibilities for planting this spring.

For snow fans in the contiguous US, this winter has left much to be desired. The warm and mild season in the lower 48 and the wild snow dumps and cold weather up north in Alaska can be blamed largely on a weather pattern called "arctic oscillation." Audie Cornish gets an explanation of the weather phenomenon from meteorologist Jeffrey Masters.

Researchers counted more than 5,000 ticks to calculate the risk of Lyme disease in the Eastern U.S. Turns out the risk is high in the Northeast and nearly zero in the South.