Introduction to Golden Rain-tree:
Koelreuteria paniculata grows 30 to 40 feet tall with an equal spread, in a broad, vase or globe-shape. Rain tree is sparingly branched but with a perfectly balanced and beautiful density. Golden rain-tree tolerates dryness and casts little shade because of the open growth habit. It makes a good street or parking lot tree, particularly where overhead or soil space is limited.
Although it has a reputation for being weak-wooded, rain-tree is rarely attacked by pests and grows in a wide range of soils. Rain-tree bears large beautiful panicles of bright yellow flowers in May and holds seed pods that look like brown Chinese lanterns.
Horticulturist Mike Dirr's habit description in Woody Landscape Plants - "Beautiful dense tree of regular outline, sparingly branched, the branches spreading and ascending...in our garden, two trees literally stop traffic in late August and early September..."
Here are some photos of golden rain tree and flamegold.
Golden Rain-tree Specifics:
Scientific name: Koelreuteria paniculata
Pronunciation: kole-roo-TEER-ee-uh pan-ick-yoo-LAY-tuh
Common name: Goldenraintree, Varnish-Tree,Chinese Flametree
USDA hardiness zones: USDA hardiness zones: 5b through 9
Origin: not native to North America
Uses: container or above-ground planter; large and medium-sized parking lot islands; medium to wide tree lawns;
Availability: generally available in many areas within its hardiness range
‘Fastigiata’ - upright growth habit; 'September' - late flowering habit; 'Stadher's Hill' - deep reddish fruits.
Leaf arrangement: alternate
Leaf type: even pinnately compound; odd pinnately compound
Leaflet margin: lobed; incised; serrate
Leaflet shape: oblong; ovate
Leaflet venation: pinnate
Leaf type and persistence: deciduous
Leaflet blade length: 2 to 4 inches; less than 2 inches
Leaf color: green
Fall color: great showy fall color
Flower color and characteristics: yellow and very showy; summer flowering
Planting and Management:
Golden rain-tree bark is thin and easily damaged from mechanical impact so be careful. Limbs do droop as the tree grows so that will require pruning for vehicular or pedestrian clearance beneath the canopy. Raintree should be grown with a single leader and there will be some pruning required to develop strong structure. There is some resistance to breakage.
Golden rain-tree's root system is coarse with only a few but large roots, so transplant when young or from containers. Do not transplant in the fall as success rate is reportedly limited. The tree is considered a city tolerant tree due to tolerance to air pollution and ability to withstand drought, heat and alkaline soils. It also tolerates some salt spray but requires well-drained soil.
Golden rain-tree is an excellent yellow flowering tree and perfect for urban planting. It makes a nice patio tree, creating light shade but its brittle wood can break easily in windy weather so there can be some mess. The tree has only a few branches when it is young and some pruning to increase branchiness will increase the tree's attractiveness.
Prune the tree early to space major branches along the trunk to create a strong branch structure and the tree will be longer-lived and require little maintenance. Dead wood is often present in the canopy and should be removed periodically to maintain a neat appearance. Only single-stemmed trees trained in the nursery with well-spaced branches should be planted along streets and parking lots.