As a regular user of Dulwich Park I have a great appreciation of the lakeside Weeping Willows and their contribution to the landscape throughout the seasons. The same observation applies to this species in Belair Park, Sunray Gardens and the Mill Pond. Of course, elsewhere in Dulwich, there are isolated Weeping Willows, not close to existing open water, for example also in the Park and in the Long Meadow near the Gipsy Road roundabout. All of the waterside trees are respectably mature and some must date back to the first half of the last century. The willow species which I have seen in Dulwich, all appear to have been planted, though if left to nature an old willow would fall and replace itself in situ by suckers from the roots or new shoots from the fallen trunk. As institutional tidiness is likely to prevail here, thought should be given to the eventual replacement of these trees.

Willows show a number of interesting features, one of which is that botanists describe them as being dioecious as they have male and female flowers on separate plants. They also tend to be prolific in the production of shoots and the cut shoots normally root readily when they are pushed into moist soil, thus allowing easy vegetative propagation. The progeny are genetically identical to the parent and thus constitute a clone in the same general way used to propagate fruit trees and roses for example, but without the complexity of grafting scion or bud on to the rootstock. As a result of cloning and of the anciently established planting of willows for domestic and commercial purposes and rather more recently for amenity, some willow species do not show an even balance of the sexes on a local basis, though on a national basis there may be balance. Therefore the natural propagation of some species by seed may be rare or absent, due to a lack of male or female trees. However, given the opportunity, willows seem to hybridise readily. Clive Stace (who studied for his first degree at the King’s College Department of Botany in Half Moon Lane) stated in “The New Flora of the British Isles” (1991) that there are 59 hybrid willow combinations known in the British Isles of which 10 are hybrids between three species. The latter situation is presumed to have resulted from the cross between an existing hybrid and a third species. As far as I am aware, many of these hybrids are of natural occurrence. A botanist looking for hybrids would go to a location where two good species coexist and search for willows with intermediate characteristics.

The complexities brought about by hybridisation and the human exploitation of willows contribute to the difficulty of studying the genus and the identification of many of the 35 species and the hybrids which grow in Britain. In addition there are a number of introduced species which have become naturalised. DNA profiling should improve willow taxonomy and permit any necessary revision of the genus in floras and handbooks. However, to the field botanist, difficulties with identification are likely to remain, as for example one authority describes the Weeping Willows as a perplexing array of hybrids. The origins of the various ‘weeping’ clones found in cultivation are also obscure. As far as I can tell the Dulwich Weeping Willows appear to be Salix x sepulcralis nothovar. chrysocoma, a hybrid between the native White Willow and Salix babylonica, a Chinese species, and not Salix x pendulina, the hybrid between the native Crack Willow and the same Chinese species. In recent years other species of British willows have been included in tree plantings here, some under the auspices of the Dulwich Society via the Trees Committee and its then Chairman, Stella Benwell, and some by other public benefactors. Amongst plantings struggling to survive both human and canine attentions and establish themselves as shrubs or small trees in Belair and the Long Meadow are Osier (Salix viminalis) and the Eared Willow (Salix aurita). Osier is a native plant favoured by basket makers and often found growing near the relics of former cultivation.

In the past, when woodland was managed as a major economic resource, willows were important in the provision of ‘underwood’ for fuel, fencing, basket-making etc, by means of coppicing or, especially, pollarding. In coppicing the wood was cut back to a stool at ground level and the regrowth was harvested on a 5 to 10 year repeated cycle. Very large living remains of stools left by coppicing can still be detected in British ancient woodlands. Currently a mechanised form of coppicing is under development for biomass (bioenergy) production on a large scale and shrub willows are the crop of choice. Pollarding was used to prevent access to the regrowth by browsing livestock, by the removal of the top of the tree at a height of 2 to 5m., the new growth being taken on a repeated cycle. I have not noticed any signs of significant coppicing of any tree species in Dulwich, but there are some examples of pollarding, apparently adopted to limit the growth of individual trees, rather than the utilisation of the resultant underwood. A final point to note is that not all British willows are trees or substantial shrubs, there are for example two dwarf shrubs, respectively less than 10 and 20cm. in height and belonging to the arctic-alpine element of the British flora, which may have become extinct in Dulwich about ten thousand years ago as climate ameliorated.