R. 'Marinus Koster'

One of the parents of R. 'Point Defiance' that, in my opinion, has the largest flowers of all rhododendrons, with trusses sometimes 18-20 inches tall. R. 'Marinus Koster' was created in England by Koster M. & Sons nursery in the 1930's. Rare in the trade. This plant is most likely a polyploid with more chromosomes than other rhododendrons. Thicker leaves and stems, and larger flower clusters. Hardy to zone 7.