It’s tempting to think that the garden is barren and there is nothing to see during January and February. But if you plan the garden well there should still be plants of interest every day of the year.
One such shrub is Hamamelis x intermedia ‘Arnold Promise’(AGM). This shrub is grown for its large, yellow spider-shaped, fragrant flowers which are produced from mid to late winter and autumn foliage colour. The flowers are 2.3cm (3/4-1/2in) across, with 4 narrow petals and are borne in dense, axillary clusters. The flowers on this cultivar differ from other cultivars in that the petals curl up more giving the shrub a more delicate appearance. The leaves are broadly ovate to obovate and up to 15cm (6ins) long. The upright, vase-shaped appearance amplifies the characteristics of the parent plants Chinese Witch hazel (Hamamelis mollis) and Japanese Witch hazel (Hamamelis japonica). This plant was awarded the Royal Horticultural Society’s Award of Garden Merit (AGM) in 1993. It was introduced by the Arnold Arboretum of Harvard University, Boston in 1963.
In 1928 William Judd, the propagator at Arnold Arboetum at the time, collected seeds from the Chinese Witch hazel (Hamamelis mollis). The resulting seedlings were grown on and appeared to be hybrids. Later in 1944 Alfred Rehder named the seedlings H. x intermedia, because their character was intermediate between the parents. Only a few seedlings grew and the colours of the flowers varied from reddish to coppery-orange to yellow. But one was spectacularly different with profuse, clear-yellow, slightly scented flowers and it was given the clonal name ‘Arnold Promise’.
European settlers in the new world used the branches of Witch hazel trees as water divining rods which is one explanation as to how Witch hazel trees received the “witch” part of their common name. The name derives from the Anglo-saxon wytch meaning “bend” which is what a divining rod does when it detects water. For many years religious leaders gave dowsing a bad reputation and the name was corrupted into “witch”.
Sometimes the name is spelled with a hyphen (Witch-hazel) indicating that it is not a true hazel. The confusion may arise from the fact that the leaves resemble those of true hazels such as Corylus avellana ‘Contorta’
Size: Ultimate height 2.5-4m. Ultimate spread 2.5-4m
Time to ultimate height 10-20 years.
Plant partners: Hamamelis x intermedia ‘Arnold Promise’ looks good combined with other plants as well as a specimen plant; the evergreen Sarcococca in its many cultivars with glossy foliage and fragrant flowers contrast well with the Hamamelis. Other plant partners include Cornus, Rubus and Silver Birch.
Cultivation: This shrub will grow in any moderately fertile, but well-drained, acid to neutral soil in full sun or partial shade. They originate from East Asia and North America where they grow in woodland, at the woodland edge and on river banks and so are very hardy.
USDA Hardiness zone 5-8
Pruning: Group 2. Generally very little pruning is needed, but if the shrub becomes too large for its site some pruning can be done. After flowering, cut back flowered shoots to strong buds or young growths lower down in the plant. With mature plants cut back a quarter to a fifth of old shoots to the base of the plant.
Propagation: Cultivars can be grafted in late winter, or bud in late summer.
Pests and diseases: Hamamelis are generally trouble-free but honey fungus and coral spot may occasionally be problems to watch out for.