|This might seem silly to you (my last question, really!) but, I've been thinking about microclimates, and about why my own yard is so much colder than the surrounding area. I've come to the conclusion that even though this is supposedly USDA Zone 4, there's a range of hills about 3000 feet higher than my house about 5 miles away, and a creek that leads down from them and passes about 75 yards from my garden.
Am I understanding microclimates correctly, that extra-cold air from those hills may be flowing down the creek and arriving at my house, causing my own garden to be a zone or two colder than what USDA says? And this may be only affecting my garden, and other gardens right along this creek bed? (This is flatland, except creeks.) Should I be paying more attention to what's thriving in the gardens of my immediate neighbors, instead of what the local nurseries sell?
I know this is sort of a dumb question, but it's really important to me. I'm getting real tired of winter-killed plants!
|The contributing factors to the creation of microclimates are elevation, bodies of water and valleys, so your observations are correct. Even though you have been placed into the broad USDA category of zone 4, you may actually be much colder or much warmer than the average low winter temperatures for that gardening region. A more reliable source of zone identification for you might be from Sunset Western Garden Book. The authors have researched the elevation and proximity to water for all areas in all of the western states and place you in their zone 2. This is the second coldest western climate with annual low temperatures ranging from -3F to -34F.
With this in mind you might want to consult Sunset's Western Garden Book for plant suggestions and a thorough explanation of their climate zones. Most gardening outlets and library's have copies of the book. (ISBN# 0-376-03851-9)