'Mikkeli' or 'St. Michel' is a Finnish variety combining excellent habit with extreme hardiness. It is a cross between two hardy wild species growing at Arboretum Mustila, the pollen from a Smirnow rhododendron (R. smirnowii) being put on a R. brachycarpum var. tigerstedtii (known as the Mustila Rhododendron) specimen: the variety has inherited the best characteristics of both parents.
The large red flower buds open in June as large pale blossoms, whose faint pink gradually turns pure white. The upper petal is attractively spotted with green. New shoots are covered in soft white down. The undersides of the old leaves are coated in yellowish down, or indumentum.
There have been reports that 'Mikkeli' sometimes doesn’t flower well, which is true for young shrubs. However, as it matures, flowering improves considerably. In ten years, ‘Mikkeli’ grows to about 2 metres and continues to increase in height over the years.