Thursday, July 16, 2009

The "Green Lull"

Thomas Jefferson used to refer to the progression of blooms in his garden as acts in a play. Tulips were an early act; lilies were a later act. If we extend Jefferson’s analogy, the prairie must be in intermission right now. This period is sometimes called the “green lull,” the time when spring blooming plants have finished and the fall goldenrods, asters, compass plants and other beauties, haven’t opened yet. Having just driven home from St. Louis to Chicago two days ago, I might amend “green lull” to “green and dull.” There just wasn’t much to look at!

Admittedly my botanical skills are challenged at 70 miles per hour, but I did recognize a few glimpses of color as I drove along. Native species were few and far between, but I did see bee balm (Monarda fistulosa), purple coneflower (Echinacea purpurea) and common milkweed (Asclepias syriaca) in full bloom. It was also nice to see many plantings of the native whorled milkweed (Asclepias verticillata) blooming along steep banks of overpasses. It is a substitute for another erosion control plant, crown vetch (Coronilla varia) which has widely escaped and is considered invasive. Other invasive species seen blooming along the route were teasel (Dipsacus spp.) and the first purple spikes of that wetland scourge, purple loosestrife (Lythrum salicaria). Although it’s tempting to put a hardy plant in your garden that defies the green lull with its showy purple blooms, please don’t do it. Purple loosestrife is invasive across the US (worst in the Midwest and northeast) and can take over a wetland in a blink of an eye. Cultivars reported to be sterile are not; they will easily cross with other cultivars or the wild type of the species. Purple coneflower, blazing star and lobelia will also give you color this time of year and are great substitutes that will not harm the environment.