Rhododendron arboreum

Rhododendron arboreum – Tree Rhododendron

Trusses of pink bells cover this substantial tree in early spring.


This is an evergreen tree that typically grows to about 12m in Karin’s Garden. In the wild it will often grow to 20M and the tallest specimen known is 33M and still growing. The trunks are typically bare, creating a house-sized space underneath the canopy. In the wild, flowers can be red, white or pink, though I know only pink in Motueka. The dark green leaves, up to 20cm long, have a smooth cinnamon-brown furry coating [indumentum] on their undersides


R. arboreum comes from the Himalayas, and it is the national flower of Nepal. The name Rhododendron translates from the Greek as “rose tree”, though the flowers do not look anything like any rose and it is in the Ericaceae family not Rosaceae. The specific name abroreum is much more appropriate, translating as “tree-like”.

Soil / Aspect:

R. arboreum, like all Ericaceae that I know, prefers acidic soil; and it does prefer moist soils. Its base and surrounding area really needs to be shaded by other trees and shrubs. It is entirely at home in Karin’s Garden, where there are many specimens on view as you drive around in late August and early September. They can also provide a wonderful display if the petals fall onto bare ground, as you can see here at Toad Hall in Motueka:

The bare trunks visible here are those of the plant that shed this carpet of petals.


Once established this is a very low maintenance plant. Especially when young, this is a woodland plant in the wild, and requires shade. When not young, it is the woodland! It does grow slowly but that still does not make it suitable for any but the largest gardens as it really cannot be satisfactorily pruned to  shape/size.