These long, last summer days are beginning to pass by quickly. To make your garden minutes count, get in the habit of harvesting vegetables and herbs as a part of your evening meal preparation. A patch of garlic chives will season family meals with a heady bite and continue in the garden for many years. A few freshly picked sugar snap peas, a sprig of parsley and a handful of strawberries will not only enhance your meal but give you one more chance to putter around in the garden.
Climate zone maps have been devised to show where various permanent landscape plants can adapt. If you want a shrub, perennial or tree to survive and grow year after year, the plant must tolerate year-round conditions in your garden. This includes the lowest and highest temperatures, as well as the amount and distribution of rainfall. Gardeners need a way to compare their garden climates with the climate where a plant is known to grow well. Zone maps provide this critical climate information.
The U.S. Department of Agriculture Hardiness Zone Map divides North America into 11 separate zones. Each zone is 10 F warmer or colder in an average winter than the adjacent zone. (In some versions of the map, each zone is further divided into “a” and “b” regions). The USDA map is the one on which most gardeners in the eastern United States rely. Many gardeners in the Pacific Northwest prefer the zone map in the Sunset Western Garden Book, since the book also includes encyclopedic information about the plants that do best in our area.
In the West, many factors beside winter lows, such as elevation and precipitation, determine growing climates. Weather comes in from the Pacific Ocean and gradually becomes less marine (humid) and more continental (dry) as it moves over and around the Cascade mountain range. While cities in similar zones in the East can have similar climates and grow similar plants, in the West it varies greatly. For example, the weather and plants in low-elevation Clark County are much different than in high-elevation, inland Tucson, Ariz., even though they are both in USDA zone 8.