How to Plant, Prune, and Understand a Golden Rain-Tree

How to Plant, Prune, and Understand a Golden Rain-Tree 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 paniculataPronunciation: kole-roo-TEER-ee-uh pan-ick-yoo-LAY-tuhCommon name: Goldenraintree, Varnish-Tree, Chinese flametreeFamily: SapindaceaeUSDA hardiness zones: 5b through 9Origin: not native to North AmericaUses: container or above-ground planter, large and medium-sized parking lot islands, medium to wide lawnsAvailability: 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. Stadhers Hill produces deep reddish fruits. Foliage and Flowers Leaf arrangement: alternateLeaf type: even-pinnately compound, odd-pinnately compoundLeaflet margin: lobed, incised, serrateLeaflet shape: oblong, ovateLeaflet venation: pinnateLeaf type and persistence: deciduousLeaflet blade length: 2 to 4 inches, less than 2 inchesLeaf color: greenFall color: vivid fall colorFlower 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-trees root system is coarse, with few (but large) roots. Transplant these trees when theyre 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 trees attractiveness. Prune the golden rain-tree while its 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.