Feathery compound foliage of bipinnate golden raintree is accentuated by airy clusters of yellow flowers in summer, and papery, pinkish tan seedpods soon thereafter. A rounded deciduous tree with an irregular branching habit with cracking gray bark, it hails from southwestern China.
The leaves are bi-pinnately compound - a central leaf stem petiole branches again into lined stems of long, pointed, tooth-edged, bright green leaflets. Emerging leaflets are light green with a coppery cast. In late summer thin, wispy-stemmed clusters of yellow flowers arise from branch tips creating a lovely display above the dark green foliage. The individual flowers are small, four-petaled, and have a tiny orange speck at the petal bases. The pods that quickly form after being pollinated by bees are papery, three-chambered pods that are often called "Chinese lanterns", dangling from the branches. They are rosy-pink when young, gradualy drying to be more a pale rosy-tan. A tree filled with the pods is perhaps as pretty as when in flower, but is certainly a differently textured display. The seeds readily germinate around the base of the tree, leading to weedy seedlings in the landscape. In fall the foliage can turn a quickly turn an inconsistent yellow before dropping.
Bipinnate golden raintree is tolerant of many conditions and are great urban trees tolerant of pollution, heat, salt and drought. It excels in well-drained soil and full sun but will grow in partial shade. It has an open, rangy, leaning habit and brittle wood which breaks during windstorms or from heavy snow or ice. Prune 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 is great in providing broken shade to patios, as a street tree or in small yards and landscapes, although quite messy.
Golden raintree may be considered a noxious weed or a prohibited invasive plant in some warm temperate climate regions. (info source: Learn2grow.com)
Genus - Koelreuteria
Species - Bipinnata
Common name - Chinese Flametree
Pre-Treatment - Required
Hardiness zones - 6 - 9
Height - 30'-35' / 9 - 11 m
Spread - 25'-30' / 7.60 - 9 m
Plant type - Tree
Vegetation type - Deciduous
Exposure - Full Sun, Partial Sun
Growth rate - Fast
Soil PH - Acidic, Neutral, Alkaline
Soil type - Clay, Loam, Well Drained
Water requirements - Drought tolerant, average water
Landscape uses - Feature Plant, Shade Trees, Street Trees
Germination rate - 85%
Bloom season - Summer, Late Summer
Leaf / Flower color - Green, Dark Green / Yellow, Orange
|Soak seeds with hard seed coats in a bowl filled with warm water. Soak them for at least 24 hours until the seeds swell.
Nick very hard seed coats that do not swell after soaking for 48 hours with a sharp knife then soak them until they swell.
Pour lightly moist coir, composted tree bark or sphagnum peat moss mixed with a handful of course builder’s sand, perlite or vermiculite into a small, zip-top clear plastic storage bag.
Put the swollen seeds into the mix in the plastic bag and zip it closed. Store it in the refrigerator for three to four months.
Pour moistened seed germination mix, such as half sphagnum peat moss and half course builder’s sand, perlite or vermiculite into a seed flat or 7-10 cm deep pots. Remove the seeds from the refrigerator. Plant the seeds at a depth equal to one to two times their width.
Put the seed containers in a bright area out of direct sunlight where room temperatures are +18-20C.
Cover the container with a piece of plastic or put the container in a large, clear plastic bag and close the top. Moisten the seed mix if it begins to dry.
Remove the cover after the seeds germinate and you can see the tops of the seedlings. Continue to keep the seed mix moist.
Pot them up separately with soil-based potting mix in 15 cm deep pots when they are large enough to handle.
Information source: http://living.thebump.com/propagate-golden-rain-tree-6820.html