Tree · Sapindaceae
Golden Rain Tree
Koelreuteria paniculata
A tough shade tree that lights up midsummer with sprays of yellow flowers and papery lantern pods.
Full sun
Every 7–14 days
USDA 5–9
30–40 ft · 9.1–12.2 m
Overview
The golden rain tree earns its name in summer, when the whole crown fills with loose sprays of small yellow flowers. As the bloom fades it sets papery seed pods shaped like little Chinese lanterns, and those hang on into fall. It is a deciduous shade tree in the soapberry family, with divided leaves and a rounded, spreading head.
What sells most gardeners on it is how little it asks. It shrugs off drought once its roots are down, takes clay, sand, or thin rocky ground in stride, and stands the cold all the way to -20°F (-29°C). Give it full sun and decent drainage and it more or less raises itself.
There is a catch worth knowing before you plant. The tree drops seed in huge numbers and sows itself freely, enough that it has turned weedy and invasive across parts of the eastern and southeastern US. Where that is a concern, rake up the pods or pick a spot where stray seedlings are easy to pull.
Care
The short version: full sun, well-drained soil of almost any kind, and a deep drink during long dry spells once the tree is young. After the first year or two it mostly fends for itself, and a light prune in late winter keeps the frame strong.
Light
Plant it in full sun for the heaviest flowering, though it will take part sun without much complaint. The more direct light it gets, the fuller the summer bloom.
Water
Water a young tree regularly through its first year or two while the roots reach down. After that it is drought tolerant and needs a drink only during long dry spells, so let the top half of the soil dry between waterings.
Soil
Few trees are this easygoing about soil. It grows in clay, loam, sand, and even shallow rocky ground, asking only for decent drainage, and handles a wide pH from 6.0 to 8.0.
Temperature
This is a cold-hardy tree, comfortable from -20°F to 100°F (-29°C to 38°C). That range covers a lot of climates, which is part of why it has spread so widely.
Humidity
Ordinary outdoor air suits it, so there is no humidity figure to watch. Good drainage matters far more than anything happening above ground.
Feeding
It rarely needs feeding at all. If growth looks poor, a single dose of balanced slow-release tree fertilizer in spring is plenty, since this tough tree is not a heavy eater.
Pruning
Prune in late winter while the tree is dormant to build one strong central leader and to cut out crossing, weak, or dead branches. The wood runs a bit brittle, so a sound frame built early pays off later.
Repotting
A landscape tree stays in the ground, so repotting is not really a concern. In a container, move it up only when roots circle the pot, water runs straight through, or top growth stalls.
Size & spacing
Give it real room. A mature golden rain tree reaches roughly 30 to 40 feet (9 to 12 m) tall and spreads about as wide, so site it well clear of buildings and overhead lines.
When to plant
This is a tree for the long game rather than a planting season you race against. Set it out in spring after the last frost or in fall, expect the yellow flowers in early to midsummer, and watch the lantern pods follow and carry the show toward autumn.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter, after seed scarification and cold-moist stratification
- Plant: Spring after last frost, or fall
- Harvest: Summer (June to July; cultivar 'September' blooms August to September)
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
A healthy golden rain tree gives you little to fix. Most of what does come up is either a wilt disease in the wood or a harmless swarm of bugs on the seed pods. Match what you see below and act while the tree is still vigorous.
Sudden one-sided wilting with brown streaks in the wood
One-sided dieback with dark streaking in the sapwood points to verticillium wilt, a soilborne fungus that has no cure. Canker or coral spot fungi can do the same to wood that is already stressed or wounded, and waterlogged ground brings on root rot. Prune well below the damage, disinfect your tools between cuts, and improve drainage so the tree stays vigorous.
Fix:
- Prune out and destroy affected branches well below symptoms, disinfecting tools between cuts
- Improve drainage and avoid drought and mechanical wounding to reduce stress
- Remove severely declining trees, as there is no cure for verticillium wilt
Clusters of red-and-black bugs on the seed pods
Those red-and-black swarms on the papery pods are the goldenrain tree bug, a boxelder relative that feeds on the seeds. It is a nuisance more than a real threat, so you can leave it be, or knock the bugs off with a strong jet of water or insecticidal soap. Raking up the fallen seed capsules takes away the food that draws them, and a horticultural oil handles any scale that builds up on the twigs.
Fix:
- Tolerate the bugs where possible, as they are a nuisance rather than a serious threat to tree health
- Knock bugs off or spray congregations with a strong stream of water or insecticidal soap
- Treat heavy scale infestations with horticultural oil
Toxicity
Good news for households with pets and children: this tree is not poisonous. Despite the alarming name, golden rain tree carries no toxin and does not appear on ASPCA toxic-plant lists. Don't confuse it with the genuinely poisonous golden chain tree, Laburnum, which is a different plant altogether.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Safe
Cats can brush past or nibble this tree without harm, as it carries no toxin known to affect them. A cat that gorges on any greenery may still bring up a hairball or a little foliage, which is normal rather than a sign of poisoning.
Dogs Safe
No toxic compound makes this tree a danger to dogs. A pup that chews a fallen seed pod might get a passing bout of loose stools from the roughage, but there is nothing to treat beyond keeping water on hand.
Horses Safe
Horses can graze near a golden rain tree without concern, since it holds no toxin that affects them. This is the unrelated cousin of the dangerous golden chain tree, so the worry that surrounds Laburnum simply does not apply.
Rabbits Safe
The leaves pose no poisoning risk to rabbits. As with any new green, introduce only small amounts so a sensitive gut has time to adjust.
Livestock Safe
Cattle, goats, and sheep can share a pasture with this tree safely, because it is not toxic to grazing animals. Heavy browsing on any single plant can unsettle a stomach, but that is ordinary overeating, not poisoning.
Birds Safe
Birds face no toxic threat from the foliage or seeds, and many simply ignore the papery pods. Backyard poultry can forage beneath the canopy without trouble.
People Safe
This tree is not poisonous to people, and the common name causes far more alarm than the plant ever does. Even so, the seeds are grown for show rather than the plate, so there is no reason to eat them.
No special handling required; as with any plant, discourage pets and children from chewing on foliage or seed pods to avoid mild stomach upset.
Varieties
Only a few selections turn up in the trade, and one near relative often gets sold alongside the species. These are the ones worth telling apart.
'September'
This cultivar holds its yellow flowers back until August and September, stretching the show weeks past the usual summer bloom, though it gives up a little winter hardiness in the trade.
Koelreuteria bipinnata (Chinese flame tree)
A close relative with twice-divided leaves and showy rosy-pink lantern pods, it runs more tender and suits warmer zones than the golden rain tree itself.
How to propagate
You will likely meet your first golden rain tree as a self-sown seedling, because this tree multiplies with no help at all. To raise more on purpose, you can start from seed or take root cuttings.
SeedModerate
Sow in fall outdoors, or stratify and sow in late winter to early spring · Seedlings appear in weeks; several years to a sizable tree
The tree sets seed by the bucketful, and it self-sows so freely that you rarely need to start it on purpose. To raise it deliberately, nick the hard seed coat and give the seed a spell of cold, moist stratification, sowing outdoors in fall or in late winter to early spring. Seedlings push up within weeks, but count on several years before you have a tree of any size.
Stem cuttingsModerate
Dormant season for root cuttings · One to two growing seasons
Root cuttings taken in the dormant season are the usual way to clone this tree, and named cultivars are reproduced this way rather than from seed so they come true. Give a rooted cutting one to two growing seasons to establish before you expect much top growth.
Myths
Golden rain tree is the poisonous golden chain tree and a danger to pets.
The two trees only sound alike. Golden rain tree sits in the soapberry family and does not appear on ASPCA toxic-plant lists, while the genuinely poisonous golden chain tree is Laburnum, an unrelated legume. Mind the botanical name, Koelreuteria paniculata, and you can plant this one without worry.