Propagation
Collect the seeds when green and they can be sowed directly or stratify for 2 to 3 months and then place in a cold frame. Germination may take up to 1 year. 

Botanic information
Leaf: The ovate to oblong leaves are up to 65 mm (2½in) wide with double-serrated margins and an acuminate apex. The petiole is to 12 mm (½in) long and leave base is sub-cordate to truncate. The thin leaves are softly pubescent and during autumn the mid-green leaves turn golden-brown before falling.

Flower: The small crateriform greenish flowers have 4-narrow elliptical pubescent sepals with exserted stamens. They are arranged in a short glabrous pendant raceme that is 50-80 mm (3⅛in) long on a short peduncle, and appear during mid-spring. 

The pistillate flowers consist of a narrow-ovate petals and the slender pedestal is up to 25 mm (1in) long and appear on a diffrent tree (dioecious) during late spring
Note
The petals are often absent in the staminate flowers. 

Fruit: The twin samara have ascending wings up to 30 mm (1⅛in) long and a slender pedestal. The small seeds are viable but the plant may be reproduced vegetatively.

General information on pruning Acer species 
The Maples normally do not require regular pruning apart from damaged, diseased or dead wood removal and this should be carried out from autumn to winter. Pruning in late winter or spring may result in bleeding of the sap and should be avoided. Remove reverted branches in variegated trees and clean up split bark with a sharp knife and allow for natural healing.