THE RHODODENDRON GARDEN

THE LAPLAND ROSEBAY, WISCONSIN'S ONLY NATIVE RHODODENDRON (Photo courtesy of the Wisconsin Herbarium Consortium)

THE FRONT YARD RHODODENDRON GARDEN

Thursday, 8:45 AM.  44 degrees F at both the ferry dock and on the back porch.  Wind ENE, mostly calm with very light gusts.  The sky is mostly clear with some scattered clouds and haze, the humidity 93%.  The barometer is falling, predicting a chance of rain tomorrow and Monday, with mixed skies, and temperatures rising into the mid-sixties.  It will cool off perhaps ten degrees next week with further mixed skies.
   A few years ago I decided  to plant some Rhododendrons and azaleas in the increasingly shady and protected front yard, which is sheltered by a medium sized white pine,  a large Colorado spruce and several other conifers. The shade, wind protection and acidic soil made it a seemingly ideal location.  The planting includes a half-dozen PJM hybrids, several hybrid rosebay rhododendrons and a few of the 'Lights' azaleas, introduced by the University of Minnesota.  They have all at last become pretty well established, and bloom fairly dependably, but it has taken longer than I expected.  The PJM's are blooming now, but it will be a few weeks before the others flower.  Azaleas and Rhododendrons are all in the genus Rhododendron, the main difference between them being that rhododendrons are mainly broad-leaved evergreens, and azaleas are deciduous.  Azaleas in particular tend to have rather garish flower colors and can be hard to fit into a landscape, but they can be very spectacular.  I think the genus needs to be isolated in their own garden environment, at least where they are not visually compatible with the native flora.
   Rhododendrons are a finicky group of plants, even in Bayfield, but there are a few that are definitely hardy and are very colorful bloomers.  PJM is a 1939 hybrid of the Korean rhododendron,  introduced from Weston Nursery of Boston, and grows and flowers dependably.  They are a glorious sight in our springtime, sturdy broad-leaved evergreen shrubs covered with pink-purple blooms.
  It is hard to be specific about the names and lineage of individual plants, since the original PJM has been much crossed over the years and unless one knows the exact name and history of an individual plant one can only generalize, and identify them simply as PJM.  The Rhododendron Society web page goes into a considerable amount of detail about these beautiful plants.
   The 'Northern Lights' series, introductions from the University of Minnesota, are very hardy azaleas in a variety of flower colors ('Orange Lights', 'Rosy Lights', etc.).
   There are also hardy introductions from Canada and Finland.  I even see some individually hardy flame azaleas here along the Big Lake, which are usually hardy only much further south.  Generally speaking, azaleas and rhododendrons need loamy, acid soil and a shaded and protected environment, but perhaps less shade the further north they are grown.
   Wisconsin has only one native Rhododendron, the Lappland Rosebay, Rhododendron lapponicum, a relict species left ten thousand years ago by the retreating glaciers in the deep valleys and ravines along the Wisconsin and Kickapoo Rivers in south-central and south-western driftless (unglaciated) region of Wisconsin.  Their habitat is primarily the shaded, moist sandstone cliffs above the rivers.  It is a Wisconsin endangered species.
   Rhododendron lapponicum is also found in the New England states,  New York and the mountains of Pennsylvania and in Canada