Pronounciation: See-EYE-ba spee-see-O-sa
USDA 9 (coldest winters may damage young trees)-11
Landscape Use: Specimen tree, accent/focal point tree for mesic landscape design themes only, a beautiful skyline tree when large and mature.
Form & Character: Semi-summer deciduous upright tree, spiny trunk enlarged at base, green when young aging to gray, canopy spreading with age.
Growth Habit: Rapid growth when young, slowing with age, 30 to 60 feet in height depending on water availability and climate.
Foliage/texture: Palmately compound leaves, orbicular, 7 leaflets per leaf, each are lanceolate in shape to 5 inches long; medium coarse texture.
Flowers & fruits: Flowers white to violet (mostly pink), 3 to 5 inches across, petals pubescent, fruits are an oblong capsule to 8 inches, green when immature later turning brown and opening to reveal silky floss coverd seeds that look like cotton.
Seasonal color: Floss silk tree blooms profusely during late summer and fall (in Phoenix) often before or when tree is deciduous.
Temperature: Young trees can be damaged by temperatures below 25oF.
Light: Full to partial sun is mostly required in lower desert landscapes. Silk floss tree is absolutely NOT for use on western or southern exposures with reflected sunlight.
Soil: Rich in organic matter, yet fast draining is best. No high pH soils with caliche.
Watering: Needs regular water in desert locations. Protect from drying persistent winds.
Pruning: Discretely and slowly raise the canopy base.
Propagation: Difficult by seed.
Disease and pests: Root rot if soil poorly drained.
Additional comments: In Phoenix, floss silk tree is an unusual accent tree of limited use because of its potential size and temperature (both excessive heat and cold) sensitivities. In contrast, it performs superbly in Southern California coastal areas and is the "official tree" of Los Angeles (even though it's an exotic tropical tree from South America). In Phoenix, this tree MUST be planted in mesic areas surrounded by greenery. Grafted cultivars include 'Los Angeles Beautiful' (wine red flowers) and the thornless 'Majestic Beauty' (rich pink flowers). Silky seed floss is used for stuffing pillows (somewhere in the world, but not in my house).