Rhododendrons and azaleas
tend to be rather sensitive to their growing conditions.
In their native habitats, most of them come from areas
with long, cool summers and soils that are both well
drained but moisture retentive. They also do best in an
acid soil between pH 4.5 to 5.5.
In many parts of the
United States
it is very difficult or
impossible to please all types of rhododendrons and
azaleas. Either the summer sun is too hot or the soil is
alkaline or the winter winds are too cold or the soil
has a high clay content and is poorly drained.
In the southeastern
states like North and South Carolina and in the
Pacific
Northwest, rhododendrons do fantastically well. Some
species are actually native to these regions and were
"discovered" by European plant explorers a couple of
centuries ago. In
England, Ireland or western France,
you can see huge rhododendrons covered with massive
blooms in the spring and early summer. Those
locales have the ideal climate and soil conditions for
these plants.
In the
American Midwest and other regions, it is quite a
different story. Occasionally individual home gardeners
will luck out and have just the right protected site
with the proper soils. Sometimes, a gardener will mix
the correct portions of acidic soil amendments to create
the ideal site. However, more often, a newly planted
rhododendron will look great the first year and then
begin to die back with each succeeding winter.