Propagation
The seeds require moist stratification at 20º C (68°) to 30º C (86°F) for 28 to 60 days, followed by 80 to 90 days at 5º C (41°F).  Fresh green seeds have a higher germination rate than the hardened dry seeds and the green seeds will germinate the following spring. 

Take cuttings from mid to late spring up to 200 mm (8 in) long and a place in a media composed of perlite and peat moss. After roots appear the cuttings require a dormancy period until spring when they should be pot up. 

Cuttings can be difficult and unreliable and cultivars are normally grafted onto seedling stock.

Botanic information
Leaf: The grey-green leaves are is ovate to oblong with an acuminate apex and prominent venation. The margin may be biserrate and the petiole is pubescent, up to 12mm (½in) long. During autumn the leaves turn a deep orange-red before falling.

Flower: The female (Pistillate) flowers consist of perianth segments that are adnate to the ovary with 6-10 teeth along the top and a short style with a linear stigma. They are arranged in catkins up to 20mm (¾in) long and the yellowish male (staminate) naked flowers have 3-15 stamens and arranged in a pendant catkin up to 35mm (1½in) long on a different tree. They appear during spring. 

Fruit: The fruiting catkin is up to 100mm (4in) long and contains achene-like nuts that are enclosed in a 3-lobed, papery bract. They fall from the tree during autumn and are very viable but the plant may be reproduced vegetatively.

Note
It naturalises in woodland settings and rarely attained its mature height under cultivation.