Golden rain tree is a small to medium sized deciduous tree native to China and Korea. The overall shape is irregular to round, sometimes with multiple trunks. The large leaves are compound with leaflets that are irregular, roughly oval and coarsely toothed or lobed. Leaves emerge in spring light to medium green tinted with pink or bronze; they are bright green in summer and turn unreliably buttery yellow in the fall. Summer blooms appear at the ends of the branches in large clusters or panicles. They are small, yellow and open over several weeks. The seedpods are also showy, being papery like small Chinese lanterns and are greenish pink to red maturing to tan and brown. Golden rain tree can be a bit messy dropping flowers, seedpods and many small twigs.
Golden rain trees are tolerant of many conditions and are great urban trees tolerant of pollution, heat, salt and drought. They prefer well drained soil and full sun but will grow in partial shade. They have open, rangy, leaning habits and brittle wood which breaks during windstorms. Prune them while young to establish good branch structure and a tidy shape. The seeds of this tree are fertile and pop-up around the landscape. It has naturalized in Japan and is becoming invasive in some locations. Golden rain trees are excellent in providing broken shade to patios, are good street trees and work well in small yards and landscapes, although quite messy. (source: learn2grow.com)
Genus - Koelreuteria
Species - Paniculata
Common name - Golden Rain Tree
Pre-Treatment - Required
Hardiness zones - 5 - 8
Height - 20'-35' / 6.1m - 10.7m
Spread - 20'-35' / 6.1m - 10.7m
Plant type - Tree
Vegetation type - Decidious
Exposure - Full Sun, Partial Sun
Growth rate - Fast
Soil PH - Acidic, Neutral, Alkaline
Soil type - Clay, laom, Sand, well drained
Water requirements - Average Water
Landscape uses - Feature plant, Shade Trees, Street Trees
Germination rate - 82%
Bloom season - Early Summer, Summer, Late Summer, Early Fall
Leaf / Flower color - Green / Yellow
|Germination||1. Pre-soak seed for 24 hours in hot water. If they swell up then sow in a cold frame. If they do not swell then soak it for a further 24 hours in hot water (50°C / 120°F) prior to sowing. This should cause the seed to swell but, should this fail, scarification followed by a further 24 hours in warm water should do the trick. |
To “scarify” the seed take a sharp knife, file or sandpaper and cut or file the hard seed coat away. Do it gently, until you see the white inner of the seed. This will allow water to penetrate the seed itself. Take care not to damage the seed embryo, or your fingers!
2. The seed need to go through the cold of winter to germinate. If sowing in the autumn or winter, sow into 7.5cm (3in) pots, cover the seeds with 5mm (¼”) of soil and a sprinkling of fine grit and place them in a sheltered position in the garden.
The compost should be kept moist but not wet at all times.
3. Some seeds will germinate in 3-4 weeks; others may germinate over an extended period. Check them from time to time and pot seedlings into larger pots as they become large enough to handle. Keep an eye on them, they grow quite fast and will need potting on sooner than you think!
If you are sowing at any other time of year, you can imitate the seasons by “cold stratification”. Place the seeds in a small plastic bag or container (film cartridges are good) fill with slightly moist sterilized peat moss or vermiculite and spray with a fungicidal product to help prevent mildew. Place the bag or container in the refrigerator (not freezer) for 12 weeks. Check seeds periodically, if they are germinating, sow immediately as above.
Grow on in pots until they are strong enough to plant into their permanent positions
Planting out should be done in late spring. After the last expected frosts, as although hardy, they are susceptible to frosts when young.