Most of the gardening books or magazines will tell you that winter is the time to be looking through the seed catalogues: when it's too wet, cold and miserable…
They are fully to frost-hardy and will tolerate a wide range of conditions, which include heavy shade and chalky soils. However, they will grow well in rich soil that is well drained and has full sun exposure. Watch out for the poisonous leaves and seeds. Prune in late summer.
You can propagate from seed or cuttings or by grafting.
Pests, diseases or disorders
Honey fungus may be a problem, although this genus is fairly resistant.