The Amsterdam suburb of Amstelveen was built during the 1930s along with a number of public parks, most centred around a number of waterways that wind their way through the peaty acidic soil. During the period from 1941 and 1972, garden designer and city architect Chris P. Broerse was involved in creating a series of plantings that were aimed at overcoming the problems presented by soil conditions which were inimical to the development of a conventional garden or landscape flora. Native plants of acidic and wetland soils were used in a pioneering planting scheme (King 1997). The ‘heemparks’ at Amstelveen have since become famous for their presentation of native flora to the public, particularly under the skilled management of Hein Koningen, senior advisor to the Parks Department (now retired).
The plantings at Amstelveen include areas of straightforward habitat restoration, such as wildflower meadows, dry meadow vegetation in the sandy rubble along the central reservations of roads, and woodland edge planting along roadsides. However, in higher visibility areas, especially in areas where there is considerable foot traffic, a more intensive planting style is used. Particularly in shaded areas, monocultural blocks of groundcover species, such as Asperula odorata are used, interspersed very often with taller forbs or ferns. In more open spaces there are areas of mixed wildflower forbs, but with grasses more or less absent. For example, in early June a combination of wet meadow species, Lychnis flos-cuculi, Silene dioicia, Sanguisorba officianalis and Geranium pratense, makes a highly ornamental display. King comments that ‘this parody of natural beauty is highly artificial and can only be sustained by high levels of skilled labour’ (King 1997). Hand weeding by gangs of park staff is very much a feature of life in the heemparks.
What is special about Amstelveen, however, is the way in which although there are areas of a highly selected vegetation, there is an engagement with natural processes that allows for constant change in the detail of the plantings, which is quite distinct to the rigid maintaining of an original plan that is normally seen in ornamental herbaceous vegetation management, yet is also quite different to the completely extensive approach to the maintainance of restored natural plant communities. Koningen stresses how the original plan is only a starting point for a process of natural development, as species spread by seed or stolons die out, are predated upon or overrun by other plants. Maintenance tasks include the hand weeding of undesirable species or invasively spreading desired ones, hoeing, planting and the transplanting of desired species, and tree pruning. The level of intervention required is closely related to the competitiveness of the plant species. Areas that feature species which are uncompetitive and need open conditions, such as Drosera and Gentiana spp., need frequent attention, whereas those that are composed of more competitve vegetation, for example Persicaria bistorta and Caltha palustris, need much less. Plant groupings are assembled very much on the basis of putting species together that have similar competitiveness (King 1997; Koningen 1997, 2001).
As the heemparks are quite heavily wooded in parts, the ground layer vegetation is in a constant state of flux, as trees grow or occasionally fall down or are removed. Whilst their natural shape is preserved, pruning and thinning are necessary to maintain the patchwork of light and shade which allows the development of a gradation from one microhabitat to another, over both space and time. This effect is also a vital part of the heemparks’ charm for visitors (King 1997; Koningen 1997, 2001).1
Key to success here is the craft tradition of vegetation management, built up over many years, with specialised Parks Department staff responsible and whose training involves the development of a creative, almost artistic sensibility, as well as a high level of horticultural skill. Koningen reckons it ‘takes 5-6 years to form a fully skilled heempark-worker’ (Koningen 1995).