Rhododendron 'Crater Lake'

Rhododendron 'Crater Lake,' used as a hedge in my front garden, is in bloom. April 2025.

Rhododendron 'Crater Lake' is a small-leaf, purple-flowering rhododendron that looks more like an evergreen azalea than a rhododendron, which most of us associate with large leaves. Rhododendrons and azaleas are in the same genus: Rhododendron. What separates them is that what we call rhododendrons have 10 stamens and what we call azaleas have 5 stamens. Since R. 'Crater Lake' looks and behaves like an evergreen azalea, I can clip it into a hedge, which you should never do with a large-leaf rhododendron (or a deciduous azalea for that matter). The literature says the mature height of R. 'Crater Lake' is five feet. My experience inclines me to estimate seven or eight feet.

'Crater Lake' was developed by Oregon Rhododendron hybridizer Dr. Carl Phetteplace, from a cross between R. augustinii 'Barto Blue' and 'Bluebird.' Interestingly, R. 'Barto Blue' was named after Oregon rhododendron hybridizer, James Barto, who was the source of Phetteplace's original rhododendron collection.