The beauty and diversity of willows

Neglected beauties

There are 300-500 species of willows worldwide and as many hybrids again. They vary from tall timber trees to tiny creeping prostate shrubs and there is a willow species for every situation irrespective of the size of your garden. Although willows are widely cultivated for their catkins, winter twigs and weeping habits the most common varieties are often inferior in beauty and disease resistance to other lesser known treasures. It is high time that some of these willows should be thrust into the limelight and become more widely available.

Arctic and montane willows

There is an abundance of small to medium willows suitable for gardens with limited space. These include those suitable for rockeries and sink gardens such as Salix lanata, S. x boydii, S. apoda and S. cashmiriana . There are many incredibly beautiful European and Asian willows that are largely unknown including, S. helvetica, S. appenina, S. magnifica, S. nakamurana ‘Yezo alpina' , S. hymalayas and S. moupinensis . The hardiness of S. magnifica (magnolia like leaves) and S. moupinensis (large scarlet red buds) has been re-evaluated in recent years and these striking willows are likely to become mainstays of winter gardens. Certain prostate forms such as S. alpina and S. retusa can be used as ground cover.

Glossy leaved willows

Many willows have striking shiny leaves similar to bay trees. These willows can be grown as deciduous alternatives by pollarding at a height of 1m. The advantage of the willows over bay and laurel trees are the golden anthers that emerge at the same time as the leaves each spring. Examples include S. pentandra ‘Patent Lumley' and S. lucida.

Curiosities

Most people are familiar with twisted willow used in home decoration. However, there are other willows that could be put to similar use or provide an unusual spectacle for the larger garden. These include S. baylonica ‘Crispa' whose leaves are curled into tight rings, S. sachalensis ‘Sekka' which has fasciating (flattened) stems and superb winter colour and S. subopposita which is a dwarf shrub with hebe-like leaves.

Pussy willows

Generally male willow catkins tend to be yellow or gold but other striking colours are less well known such as black (S. gracilystyla ‘Melanostachys'), pink ( S. myrtilloides ‘Pink Tassels' and S. purpurea ‘Howki' and red S. calyculata. Other willows seem to have more than their fair share of catkins such as the relatively common S. hastata ‘Wehrhahnii' and the less widespread S. x hungarica and S. aegyptiaca . The latter sometimes produces three catkins from a single bud. S. triandra ‘Semperflorens' is unusual in that it continues to produce catkins throughout the summer. The less lauded female catkins can also be of interest – during the development of seeds they can take on the appearance of mediaeval instruments of weaponry ( S. glaucophylloides ) or resemble fluffy baubles ( S. candida hybrids).

Weeping willows

The most well known willows ( S. babylonica, S. matsudana and hybrids) were once commonly grown in small gardens but more often than not would grow out of proportion and were held responsible for cases of structural damage to the foundations of houses. There are smaller alternatives suitable for urban gardens. The Kilmarnock willow S. caprea ‘Pendula' is common but other weeping varieties such as S. purpurea ‘Pendulina' and S. integra ‘Pendula' are much more elegant and couldn't fail to elevate the status of a small pond or water feature.

Winter twigs

Yellow and orange winter twigs are fairly common in gardens but reds and violets are less so. Red stemmed willows are probably pushed out of the limelight by the myriad of Cornus varieties. The most common scarlet stemmed willows include S. alba var chermesina ‘Britzensis' but others such as ‘Cardinalis' and S. x sanguinea ‘Yelverton' deserve greater attention. Similarly, there is absolutely no reason why purple stemmed willows should not be more widely cultivated. These include S. daphnoides and S. irrorata (which commonly have a white bloom) and are very striking in January–March when their silvery catkins turn to golden flames on male plants. Almost black stems may be found in various S. myrsinifolia, S. caprea and S. triandra clones such as ‘French Purple. A good contrast to these dark stems is the pale buff of S. x ehrhartiana which is also notable for its black buds.

Landscape trees

There are two cultivars in particular that would add beauty and diversity to the landscape of a large garden or estate. Both belong to our native tree willows, the white willow ( S. alba ) and the crack willow ( S. fragilis ). Firstly, the Bedford willow S. fragilis var Russelliana is a rich green crack willow that has a large crown and can attain heights of 30m. This is revered as being the favourite tree of Samuel Johnson. S. alba ‘Aurea' is unusual in being a white willow with yellow green leaves. When this is planted amongst more typical silvery leaved cultivars such as S. alba ‘Sericea' and ‘Argentea' an excellent contrast is achieved giving the appearance of year round autumn colour.