Introduction to the Golden Rain-Tree

A golden rain-tree with yellow foliage.

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Golden rain-tree, Koelreuteria paniculata, grows 30 to 40 feet tall with an equal spread in a broad vase or globe shape. Rain-trees are sparingly branched, but with a perfectly-balanced and beautiful density. Golden rain-tree tolerates dryness and casts little shade because of its 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 describes the golden rain-tree in "Manual of Woody Landscape Plants Their Identification, Ornamental Characteristics, Culture, Propogation and Uses" as a "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."

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
  • Family: Sapindaceae
  • 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 lawns
  • Availability: generally available in areas within its hardiness range

Cultivars

Fastigiata golden rain-tree has an upright growth habit. September flowers later in the year than other rain-tree cultivars. Stadher's Hill produces deep reddish fruits.

Foliage and Flowers

  • 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: vivid fall color
  • Flower color and characteristics: yellow and vivid, summer flowering

Planting and Management

Golden rain-tree bark is thin and easily damaged from mechanical impact. Limbs droop as the tree grows, so they will require pruning for vehicular or pedestrian clearance beneath the canopy. Rain-trees should be grown with a single leader. There is some pruning required to develop a strong structure. Rain-tree has some resistance to breakage.

The Golden Rain-Tree Root System

Golden rain-tree's root system is coarse, with few (but large) roots. Transplant these trees when they're young, or transplant them from containers. Do not transplant in the fall, as the success rate is limited at this time of year. The rain-tree is considered a city-tolerant tree due to its ability to withstand air pollution, 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. However, 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. Light pruning to increase branchiness will increase the tree's attractiveness.

Prune the golden rain-tree while it's still young to space major branches along the trunk and create a strong branch structure. This way, 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.

Source:

Michael A. Dirr. "Manual of Woody Landscape Plants Their Identification, Ornamental Characteristics, Culture, Propogation and Uses." Revised edition, Stipes Pub LLC, January 1, 1990, IL.