For the holiday weekend, we took advantage of the just-reopened North Cascades Highway, and headed up to Mazama. Mazama is situated at the top of the Methow Valley, and while not actually very high (about 2,200 feet), the ecology has a distinctly sub-alpine feel because it melts out so late and gets snow again so early. We stayed at my parents’ property, where they keep a sparse garden that is very different than their lush, overstuffed city garden. In Mazama, trees are left standing, unless they threaten to fall on the house or garage (which is a very real danger- at least 20 trees fell last winter). Most of the property is left for nature to decide what will grow there- both our time and water is too scarce to worry about cosseting plants that are further than a few feet from the house. Even when we try to control the landscape, nature usually gets her way. My mother had carefully staked a crabapple tree that was splitting down the middle, but the bear that climbed the tree and sat in it while munching on the crabapples didn’t care about what my mother had in mind for the tree.
The few cultivated plants, which form a little perimeter around the house, are at least a month behind those in Seattle. The early daffodils, grape hyacinths, and forsythia are blooming now and the lilacs are just setting buds in our shady woodland garden. It will get hot here soon, and by the end of June, the flowers will catch up with our Seattle gardens, with the oriental poppies blooming at the same time in both places. In the fall, when Seattle is enjoying the slow descent into winter, Mazama will be getting isolated snow showers, hopefully with enough snow accumulation to cross country ski by Thanksgiving.
Mazama is in USDA zone 5b, whereas Seattle is in zone 7b (the lower the number, the colder the winter is on average.) For comparison, Denver, CO, and Columbus, OH, are also in zone 5b and Atlanta, GA, and Forth Worth, TX are in zone 7b. Some folks claim that the USDA zone system works well for choosing plants East of the Rockies, but isn’t quite as useful in the West, where elevation and proximity to the ocean have major effects on which plants will thrive. I can’t speak to how easy it is to choose plants in the East, but every year I get suckered into buying something that can handle Seattle winter temperatures just fine, but dies of soggy roots instead.
An alternative to the USDA hardiness zones are the Sunset climate zones, which take into account parameters other than winter season lows, such as length of season, wind, and maritime climate. In the Sunset system, Seattle gets a zone 5. I think Mazama is a zone 1a, but the whole Methow valley is helpfully left off the map on Sunset’s web site. I’m pretty sure folks in the Methow don’t need Sunset to tell them that it’s unwise to grow tomatoes that take 85 days to mature, though- ski season in Mazama will be back before we know it.