Formosa azalea is one of the triumvirates of Indica azaleas that rule the garden centers of the American south every spring. The other two are the white Mrs. G.G. Gerbing and the pink George L. Tabor. At this point, the Belgian Indica azalea Pink Ruffles may be the finest of all.
Formosa Flower Color
Formosa’s flower color has been described in a range from soft lavender to pink to magenta to purple. I would argue with none of these descriptions. Formosa is the most purple-colored Indica azalea to my eyes, although in sunlight the flower color does indeed favor lavendar-pink. I suspect this is why there are so many widely varying pictures of Formosa online.
I know this much: Formosa is difficult to photograph accurately. All of the magenta-toned flowers share this trait.
Growing Formosa Azalea
Formosa is an Indica, or Southern Indian, azalea, which means it grows big and hardiness is limited to USDA zones 7-9. Formosa can grow seven to ten feet tall and wide. It will take five or six years at least to reach such a stately size, but it will get there so plant accordingly.
Azaleas like well-drained, rich soil and Formosa azalea is no different. Plant azaleas a little shallow to protect against winter. Being an Indica azalea, Formosa’s flower buds may be protected by planting in parts of the garden that have shelter from the winter wind.
Azaleas can take more sun than given credit for, and they will bloom better for it. This said, I would not tempt fate by planting azaleas in direct afternoon sun. This may be repetitive (if you have read about other azalea and rhododendrons on this site), but morning sun to early afternoon and then shade thereafter is perfect.
Soil must have acidic pH. Test if you live outside of the Piedmont, especially in the Coastal Plain and southwards.