Madame Masson Rhododendron Madame Masson Rhododendron flowers are star-shaped, white with a yellow blotch. Blooms are held in conical trusses. Primary Color: White Bloom Time: Midseason Height in 10 Years: 5' Hardiness (Temperature): -15 Sun / Shade: Morning Sun, Afternoon Shade Landscape Category: Shrub Genus: Rhododendron More plants in: Coming Soon Find out if this plant is available: Rhododendron and Azalea Availability List