The US Department of Agriculture produces a garden planting zone map for gardeners based on the average of low temperature readings taken from weather stations throughout the United States. The idea is to give the garden industry a way to communicate the cold hardiness of landscape plants. That is why the tag of a holly or any other landscape plant often says "hardy to zone __."
Of course, the map also provides vegetable and herb gardeners like you with a rough guide to the extent of cold where you live. Many of our perennial flowers and herbs are hardy as far north as zones 3 or 4. Cool-season vegetables, most of which tolerate or even like a little frost, will grow well in zones 7 and southward in the fall. This is roughly where we distribute transplants to your local garden center at the proper time for planting. See below to find your garden planting zone (also known as your hardiness zone), and once you do, check out our zone-based planting guides to know when to plant your favorite veggies, herbs, and more in your area.