New USDA map

USDA Plant Hardiness Zone Map

There is a new plant hardiness zone map out from the USDA. These maps are based on average minimum winter temperatures and are meant as a guide for gardeners in choosing plants, especially long lived trees and shrubs.

When using the maps you must of course also keep in mind the micro climate of your community and even of your yard. Lots of stone and concrete and shelter from the wind will make a warmer spot while a wide open space will be cooler.

The new map places me in zone 9a which I feel is a little too warm, as our minimum winter temperatures can get as low as 15 and usually do at least once a year. So I'll play it safe and buy most things that are rated for zone 8b, 15-20 degrees.  That way most of the time my plants will be hardy enough to survive winters that are a little colder than average.

However, the map is a great starting point for making decisions about which plants to buy for your landscape.