HARDINESS: Zones 5 to 9
PREFERRED SOIL pH: Acid to alkaline
PREFERRED SOIL TYPE. Adaptable, well-drained
PREFERRED LIGHT: Sun to partial shade
ATTRIBUTES: Deciduous tree with yellow flowers, decorative seedpods; for specimens
SEASON OF INTEREST: Spring to fall
FAVORITES: K. paniculata
QUIRKS: Trees planted in fall may fail in cold climates
GOOD NEIGHBORS: False cypress, lacebark pine, star magnolia, bulbs, groundcovers
WHERE IT GROWS BEST: Sunny site with well-drained soil
LONGEVITY: Lives for many years; becomes more attractive with age
POTENTIAL PROBLEMS: If unpruned, limbs may suffer wind damage
SOURCE: Nursery plants
DIMENSIONS: 40-60 ft (12.2-18.3 m} tall and equally wide
Golden-Rain Tree in The Landscape
This is one of the most remarkable flowering trees of summer. Golden-rain tree has so many unique qualities that many gardeners looking for a yard-sized shade tree put it at the top of their list. With a mature size of up to 40 ft (12.2 m) tall, and a rounded canopy of up to 30 ft (9.1 m) wide, golden-rain tree is easy to fit into most landscapes. It is beautiful as a lawn or patio specimen, where the sun can strike the flowers, making them glow. And because it has deep roots that are not invasive, you can put it in a garden and underplant it with any perennial, annual, ground-cover, or bulb that will tolerate shade. Golden-rain tree thrives in heat and shrugs off cold, although young trees can be damaged by low temperatures.
Small trees grow slowly at first and then quickly gain size after the third year. But even young trees display all the features that make golden-rain tree so popular. The feathery green leaves are divided and arranged in neat pairs, giving the tree a fluffy texture. The foliage often turns yellow in fall, where it's displayed against the dark bark and picturesque branching.
During the first heat wave of summer the tree produces yellow flowers in showy clusters that are 12-15 in (30.5-38 cm) long.They add vibrant color to the landscape for 2-3 weeks. Once the flowers fade, hollow, papery, 3-sided seedpods emerge, looking like little lanterns. They are subtle pale green, then progress through pale yellow and pinkish tones to a warm chocolate brown. The seedpods often persist into winter, producing a pleasant rustling sound in the wind.
All in the Family
Most gardeners grow the species, and while there are a few cultivars, they are proving to be less hardy. 'September' blooms later in summer, and 'Fastigiata' grows slowly into a narrowly upright tree, 25 ft (7.6 m) tall and 3 ft (1 m) wide. Other species are excellent ornamentals for warm climates. Chinese flame tree (K. bipinnata), hardy to Zone 8, is bigger all around. It grows to 60 ft (18.3 m), has larger golden flowers, and sends out 2 in (5.1 cm) long rosy salmon seedpods. The flamegold tree (K. elegans) is similar but hardy only to Zone 9.
Growing Golden-Rain Tree
Golden-rain tree will grow in any type of soil as long as the site has
good drainage. In all but the mildest climates, plant in early spring, as trees set out in fall are more prone to cold-weather injury. Small, container-grown specimens are preferred to those whose roots are wrapped in burlap, because they are less likely to suffer root injury while being handled. When planting, take care to keep the soil ball intact and set the tree at the same depth it occupied in the nursery container. Water as needed to keep the soil moist the first year, but after that golden-rain trees become drought tolerant.
Golden-rain tree has an undeserved reputation for suffering storm damage. The branching pattern is structurally sound enough to protect the tree from wind or the weight of ice. Still, it pays to prune young trees to eliminate narrow limb crotches and remove weak or crowded branches. After 5 years, it should need no pruning, and the tree seldom, if ever, has problems with pests or diseases.