Rhododendron yakushimanum

Rhododendron yakushimanum

Rhododendron yakushimanum is a species uniquely native to the island of Yakushima in Japan.  It is one of my favorite rhododendrons and they are starting to bloom now.  They have been hybridized to produce several varieties.  Altogether, I have nine of them.  Many have a flower that begins a deep magenta pink, gradually becoming white as it opens.

Japanese Andromeda (Pieris japonica), another popular garden shrub in the Pacific Northwest, is also native to Yakushima Island.

Rhododendron yakushimanum

Nicknamed "Yaks," they have a number of desirable characteristics.  They tend to be a smaller scale shrub.  I have some approaching 20 years in the garden that are still under a meter tall.  They are reliable and profuse bloomers, not fussy about weather or soil conditions.  The only care they need is removal of the spent flowers.  In my yard, they seem to be resistant to root weevil damage.  This makes them good candidates for a pesticide-free garden.  Once established, they are surprisingly drought tolerant.  Finally, like rhododendrons in general, they are evergreen shrubs that look good year around.

Indumentum

One distinguishing feature of the species is a velvety fuzz on the leaf undersides called indumentum.  It comes in a range of colors including cinnamon brown, beige, light green, and silver gray.  This plant is called 'Teddy Bear' for its rusty brown indumentum.

Rhododendron yakushimanum

Rhododendrons are members of the Heath Family (Ericaceae).  This group relies on the assistance of soil fungi (mycorrhizae) for nutrition.  This allows them to grow in relatively infertile, acidic soils.  Other members of the family include Madronas, Salal, Pieris, Enkianthus, Heather, Indian Pipe and Huckleberries.

Rhododendron yakushimanum

My plants do well in a location that gets morning and midday sun, but are shaded from early afternoon on.  They seem to thrive in the salt air on the Puget Sound shoreline.  They don't seem to mind my sandy, rocky Vashon Till soil either.  Mine have survived winter temperatures as low as 11° F (-12° C).

Our native Pacific Rhododendron does not adapt well to garden conditions.  With a similar flower color, R. yakushimanum serves as an excellent stand-in for the native garden.  They blend beautifully planted among conifers, Vine Maples, ferns, and other Pacific Northwest natives.

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