One of the super-hardy Rhododendron cultivars bred by the University of Helsinki, 'Axel Tigerstedt' is a medium-height hybrid with white flowers. Its mother plant was R. brachycarpum var. tigerstedtii and pollinator the Rhododendron degronianum shrub growing on the present Atsalearinne (Azalea Slope). It is named after Axel Tigerstedt (1930–2010), grandson of the founder of Mustila Arboretum and the Foundation's first Executive Director.
The pale-pink buds break at the beginning of June and open to pure white. Young shoots and leaf buds are covered in woolly indumentum. 'Axel Tigerstedt' grows into a roundish shrub about 1.5 metres high in 10 years.