Well, the inevitable is finally occurring—we’re going to talk about climate change. But, not in the context one might expect; you see, we are of the opinion that it is indeed getting a little warmer outside. Not because it was 60 degrees in January in Kansas City (remember the last two Januaries when everyone thought the Ice Age was coming?) but rather, looking back over the past 40 years or so, it’s just not as cold in the winter and we just don’t have as much snow as we did when we were kids growing up. Does that mean we believe in the trendy new, man-made carbon dioxide falderal? No, far from it. Temperature swings are cyclical. They come and they go; we distinctly remember in the late ‘60’s and early ‘70’s that we were being warned of a new Ice Age coming before the end of the century. Did we just miss that cataclysmic event?
We are noting the climate change for one reason: the USDA has re-drawn the Agricultural and Horticultural Hardiness Zone maps for the United States. For virtually the entire country, the local zone hardiness has been raised one step to a warmer hardiness region. For example, the Kansas City area has traditionally (at least for the last 30-40 years) been designated as zone 5. This means our lower cold limits were -10 to -20 F; our new zone 6 designation means our lower cold limits are 0 to -10F. For those professionals in the industry, this doesn’t really mean too much—we have learned through experience that many parts of the Kansas City area were zone 6. But for homeowners and backyard landscapers, the new, official designation might give them the courage to go forth and boldly plant new varieties!
The addition of zone 6 plants adds a tremendous new palette of materials with which to work; hollies, azaleas, and other broadleaf evergreens comprise much of this new group. In addition, a number of ornamental trees that thrive in zone 6 will be of great interest to local gardeners. Japanese Snowbell (Styrax japonica) is a typically zone 6 grown tree that does very well in Kansas City, as does the Japanese Stewartia (Stewartia pseudocamellia). Crape Myrtles are another traditionally southern plant that is making its way into Kansas City gardens—and not just as a woody perennial that needs to be cut back to the ground each year. Our slightly warmer winters are allowing Crape Myrtles to actually grow into large shrubs or (might I dare venture) small trees! Though professionals have grown these trees for years in Kansas City, many home gardeners have been timid about trying them—hopefully our new zone 6 designation will encourage many to try these and other adventurous varieties!
Of course all news has to come with a whole group of qualifiers—and this zone 6 news is no exception. We will state what we tell many of our clients: Plants can’t read. They don’t know what zone they are in and if it gets really cold outside—they may not like it! We would temper our enthusiasm slightly by advising that gardeners don’t go out and buy 50 Encore Azaleas and renovate their entire garden with them. Try some new varieties and see how they perform before discarding the old standbys, but do venture out into the new zone 6 world! If you have questions about particular varieties or if you would like some help with cultural suggestions for temperamental plants, contact your professionals at Greenleaf—we’re always glad to help. Happy Gardening.
Contributing editor: Don Archer, Don Archer Designs in partnership with Greenleaf Garden Services