The Heem Parks of Amstelveen

Blending nurture with nature Gardening with wildlife in mind is anything but a new idea: the Dutch have been doing so in their public green spaces since the 1930s.

NIGEL DUNNETT and NOËL KINGSBURY explain the ethos and evolution in the Netherlands, of heemparken, or ‘habitat parks’ in particular those in Amstelveen, Amsterdam PHOTOGRAPHY: JANE SEBIRE

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ITH ITS LONG HISTO Y of dyke-building,canals,

and drainage and reclamation schemes, the Netherlands has arguably one of the most artificial landscapes on Earth,and certainly one of the most densely-populated. Its packed and orderly towns and cities are matched by equally neat and intensive rural surroundings. Perhaps as a result, no other country has taken the business of habitat creation or urban flora and fauna so seriously.There has been a long and significant tradition,stretching back to the 1920s and 1930s, of bringing nature into the heart of towns and cities, in direct contact with the places where people work and live.The THE GA DEN March 2004

CREATED FROM OPEN PASTURE An unforgettable sight in Jac P Thijsse Park, on the outskirts of Amsterdam, are massed spring plantings (above) of Primula elatior (oxlips) and Leucojum aestivum (snowflakes) (right), carpeting the ground beneath Betula pendula (silver birch) young enough only shyly to begin developing its mature white bark.

Areas such as these have been developed from open pastureland over the last six decades.

Some copses have filled so well that clearing and replanting is already part of the heempark maintenance strategy THE GA DEN March 2004

Dutch heemparken, gardens as places where native flora is used for ornament and ecology, are an interesting aspect of this phenomenon.Among these,the parks of the Amsterdam suburb of Amstelveen stand supreme.

The team responsible for these was a remarkable partnership: landscape planner and designer Christiaan Broerse,who was Director of Parks for Amstelveen and had a strong sense of spatial design and a deep feeling for the patterns and dynamics of natural plant communities, and his assistant, Koos Landwehr (himself later to become Director), a practical botanist with great knowledge of native Dutch flora, and the horticultural skills to obtain, ➨ 209

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Familiar Fritillaria melagris, snake’s-head fritillary (left) is typical of the Dutch ornamental natives (many of them also part of the British natural flora) that, for maximum ornamental effect, are cultivated in the Amstelveen heemparken in higher densities than would be found in the wild. Unusually-coloured selections such as pinkflowered wood anemones, Anemone nemorosa (below left) are favoured for similar reasons

propagate and multiply native wild flowers, most of which were not then available commercially.Broerse coined the term heempark, loosely translated as ‘habitat park’,to distinguish his creations from earlier, more instructive gardens, believing that nature-like parks and gardens should be as beautiful as possible, not scientificallyaccurate re-creations of native plant communities.

He took native habitats such as woodland, bog, dune, meadow and heath as his starting point and aimed to distil the essence of their character yet maximise their aesthetic qualities.This he achieved by selecting a limited number of key ‘character species’ that defined their visual appeal, and using them in greater numbers than might be found in the wild.

Much emphasis was placed on creating a rich herbaceous layer as well as establishing an overall framework of trees and shrubs. unning throughout was the desire to counter what Broerse saw as the excesses of ornamental horticulture,where visual spectacle and high-volume colour were at the fore. Instead he promoted 210

what he saw as the ultimately more rewarding yet more subtle experience of the indigenous landscape. He was not afraid to include many non-native species from similar habitats if they added to the overall effect without distracting from strictly native plants.

Passing on the baton The best known of the heemparken is undoubtedly Jac P Thijsse Park in Amstelveen, on the outskirts of Amsterdam, named for a pioneer in environmental education of the 1920s (see box, p214) and laid out between the 1939 and 1972.

Broerse and Landwehr were responsible for the early development of the Amstelveen parks,and their tradition was continued

by Hein Koningen.A young nurseryman who specialised in carnations but with a passion for the native Dutch flora,Hein wrote to Broerse in the 1950s asking to work in the Amstelveen Parks Department, but only as a gardener in a heempark. His skill and expertise was recognised and he rose to become Supervisor of all the Amstelveen heemparken, only retiring in 2001. He states that in Amstelveen,‘green is a total system,green is a co-inhabitant,we bring it to the front door of the citizens.’He advises the best time to visit the parks is the second half of April.

At this crossover point between the early and late spring the displays of woodland herbaceous plants such as great drifts of oxlips,anemones,fritillaries and oxalis are breathtaking,while the Amelanchier that form a significant component of the woodland edges (despite being non-native North American species) are in full flower.Those areas where there is a heathland vegetation are developing into a mosaic of different foliage colours and textures with masses of deep pink Dactylorhiza majalis (marsh orchid) and odd clumps of bright yellow Arnica montana,bright green and deep red tones of sphagnum mosses and grey Erica tetralix (cross leaved heath),together with dwarf shrubs such a Calluna vulgaris (heather), Vaccinium myrtillus (bilberry), and Empetrum nigrum (crowberry), with scattered individuals of birch and juniper.

By early summer the parks change character, becoming cool, verdant tapestries of green, shot through with meandering paths, perfect for getting away from city stresses and strains. Pools (above), canals and ditches abound but even in these, the vegetation is carefully managed. Hein Koningen (left), former heempark Supervisor at Amstelveen, planned years in advance

Managing succession Broerse was fascinated by the way that natural communities change over time. In contrast to much horticultural activity, which sets itself the task of maintaining a fixed arrangement of plants, the Amstelveen management system recognised from the start that nature is dynamic,and that management should seek to steer this natural process of succession. Indeed, says Hein Koningen,‘the fluctuating,spontaneous elements in heempark vegetations of any THE GA DEN March 2004

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type are seen as essential and highly valued.’ As a result, the maintenance of the parks is refreshingly un-mechanised and flexible, relying instead on the skills and knowledge of the gardeners themselves.

Hein stresses that it takes many years of experience and training before someone is able to be both familiar with the cultural requirements of the many indigenous species,and also to develop an instinctive understanding of the subtleties of ecologicallyinformed maintenance. Hein is a vehement opponent of the modern concept of the garden or park management plan,whereby maintenance operations are carried out according to a ➨ 211

predetermined calendar. In his view, garden and park management is highly creative, with the original designer purely setting a process in motion which has no preplanned end point.Hein says the gardener must develop a clear vision,‘a strong mental picture’, of how areas may develop in 10, 20 or 50 years, and that actions are taken as and when appropriate to promote that picture.

In full sun,areas planted only with wild flowers are dramatically colourful but in fact highly time-consuming to maintain because the level of weed infiltration is high.In natural conditions visually pleasing wild flowers nearly always grow in combination with other less exciting-looking plants, which dilutes visual impact.

In the enhanced communities of the parks,painstaking weeding is required to remove unwanted species, but also to select, promote and transplant self-sown seedlings of desired plants.

In shady areas there is less of a weed problem. Much of the management of woodland and woodland edges is concerned with maintaining appropriate amounts of light reaching ground level to enable woodland wild flowers to thrive without encouraging weedy, light-demanding species.Traditional maintenance 212

operations of hay-cutting, coppicing and selective thinning and pruning of trees and shrubs take the place of the lawnmower, hedgetrimmer and petrol-driven leafblower typical of the modern British Park. No chemicals are used, apart from an annual antimosquito treatment of some water bodies.

During the early decades of the Amstelveen parks, following their creation from open fields,succession to their predominantly wooded current state went through a series of stages.Young, shrubby pioneer woody plants replaced light, open conditions, gradually giving way to larger,more mature trees and shade in the later stages.Now,much management concentrates on regeneration plantings to ‘kick-start’ the successions again.This takes place on different timescales according to the vegetation type.Apart from small patches of cornfield annuals, most open sunny areas, and those where ‘pioneer vegetation’is to be re-instated (such as birch woodland, some areas of heathland, and open path edges), are cleared and replanted with pot-grown herbaceous material or divisions (all propagated from seed and plants collected from the parks), and the spaces between plants weeded rigorously ➨215 THE GA DEN March 2004

As spring gradually gives way to summer, the woody areas of the Amstelveen heemparken take on a more shady, verdant character.

Glades are artificially opened up to increase light levels under the tree canopies and thus are filled with summerblooming wild flowers (main picture). Many of the species found here are familiar to lovers of British flora and THE GA DEN March 2004

include Leucanthemum vulgare (ox-eye daisy), Silene dioica (red campion), Lychnis floscuculi (ragged robin), Geranium pratense (meadow cranesbill) and Knautia arvensis (field scabious).

The many areas of damp woodland are ideal habitats for ferns, particularly evergreen Blechnum spicant, (hard fern) (above, middle) and the scourge of many a

UK allotment holder, Equisetum (horsetails) (left).

These provide a contrasting frothy texture to most other vegetation and are less of a menace in these wide, open expanses of park.

Even ragworts such as yellow-flowered Senecio paludosus, (fen ragwort) (above right) are welcomed for their ability to brighten shady corners

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Further reading: •Designed Dutch Landscape: Jac P Thijsse Park (Gaston Bekkers, Garden Art Press, 2003, ISBN9071570851) is a guide to the history of the Amstelveen heemparken.

•The Dynamic Landscape: Naturalistic Planting in an Urban Context (Nigel Dunnett & James Hitchmough, Spon Press, 2004, ISBN0415256208) contains a chapter by Hein Koningen on the planting and management of the Amstelveen heemparken

ORNAMENTAL NATIVES USED IN THE AMSTELVEEN PARKS

Early spring Anemone nemorosa (wood anemone), Primula vulgaris (primrose), Pulmonaria officinalis (lungwort), and pink and purple Corydalis cava and C. solida are planted to give large-scale effect, while other species melt together in a tapestry of foliage and flower: white-flowered Oxalis acetosella (wood sorrel) with the green spathes of Arum maculatum (lords-and-ladies) or frothy white Galium odoratum (sweet woodruff) among the fresh fronds of Athyrium filix-femina (lady’s fern), or Matteuccia struthiopteris (shuttlecock fern) with Convallaria majalis (lily of the valley).

One of the set-piece plantings is unforgettable at this time of year – a grove of young Betula pendula (silver birch) underplanted with Primula elatior (oxlips) – a sea of golden yellow against flaking browny-white stems, interspersed with occasional clumps of Lily-of-the-valley, lungwort,elegant white Leucojum aestivum (summer snowflake) and mauve Viola reichenbachiana (dog violet) (pp208–9). Combinations of this sort would not usually be found in the wild, but skilfully convey the essence of naturalistic woodland.

through patches of purplish Fritillaria meleagris (snake’s-head fritillaries) in wetter areas.

Later in the year these ferns punctuate the open spaces, often in association with clear yellow Narthecium ossifragum (bog asphodel), and in autumn turn to attractive russet colours. Another ubiquitous spring plant is Caltha palustris (marsh marigold), forming vibrant ribbons from March with its golden flowers along the edges of ponds and lakes. It is also a striking component of wet meadow grasslands, along with primroses and drifts of dainty mauve-flowered Cardamine pratensis (lady’s smock).

Summer

From May and June onwards, the character of the parks changes dramatically. The open flowering woodlands of spring become cool shady retreats surrounding lakes and pools. At this time parts of the parks are also at their most colourful with meadow glades full of rosy-flowered Silene dioica (red campion), brilliant-white and yellow Leucanthemum vulgare (ox-eye daisy), red Lychnis flos-cuculi (ragged robin),the pale-blue blooms of Geranium pratense (meadow cranesbill),lavenderblue Knautia arvensis (field scabious) and rich-red Late spring Sanguisorba officinalis (greater burnet) (pp212–3).

A few weeks later another birch grove also lights Later on, in August and September, tall yellow up with a carpet of yellow Chelidonium majus (greater celandine) illuminating the dappled shade. drifts of ragwort-relative Senecio nemorensis are In the damp, peaty soil ferns grow especially well, a feature in the more shaded areas, while autumn is blessed with the changing colours of the leaves none more so than giant Osmunda regalis (royal and vivid berries of shrubs such as Viburnum fern), which is planted in clumps along water opulus (guelder rose). margins and in woodland glades, emerging

In autumn, berries such as those of Rhamnus (buckthorn) (top) and seedheads of Narthecium ossifragum (bog asphodel) (middle) provide subdued charm, and the processes of decay (below) are allowed to continue unchallenged

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Jac P Thijsse Park is the most well-known example of the Amstelveen parks, constructed in stages between 1939 and 1972, and is named after Dr Jacobus Pieter Thijsse, an educationalist with a strong environmental consciousness, whose work in the 1920s provided inspiration for the heempark movement. He wrote a number of books that increased awareness among Dutch citizens of the need for nature conservation. He promoted the idea of the ‘instructive garden’, or neighbourhood botanical gardens in towns and cities, where native plants might be displayed in representations of natural plant communities.

Several such gardens were established in the 1920s and 1930s but the Amstelveen parks set a radical new direction, creating highly artistic evocations of flower-rich naturalistic landscapes. Following waterways that snake through residential areas, they are a peaceful retreat from the city, where a network of paths leads the visitor through woodland glades, along the shores of pools and among colourful drifts of wild flowers. Yet these apparently natural environments have all been constructed from former agricultural pasture and are intensively managed.

PHOTOGRAPHS : MARK BOLTON

RINKE TOLMAN

THIJSSE THESIS

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until ground cover of the desired plants is achieved.The woodlands are managed on a selective basis,with individual large trees being removed occasionally to provide space and light into the woods.

The parks are only part of the Amstelveen’s green approach.

Tramlines,roadsides and highway reservations are also an important part of the biodiversity strategy. During the 1960s Hein oversaw the development of the Beneluxbaan,a road,with verges made up of 50cm (20in) deep sand. Such a thickness is ideal for establishing a colourful wildflower community, where plants characteristic of thin low-nutrient limestone soils such as blue Salvia pratensis (meadow sage),Allium schoenoprasum (wild chives) and yellow-green Euphorbia cyparissias grow, unthreatened by vigorous species that thrive on high levels of nutrients.Today citizens enjoy these wild flowers as they commute to work.

In Britain, managers and designers of urban nature parks and wildlife gardens have tended to be in thrall to the concept of maximising biodiversity, and have a rather purist attitude to ecological-habitat creation,with little attention to the aesthetics of nature. Jac PThijsse Park and the other Amstelveen heemparken THE GA DEN March 2004

The russet tones of autumn create a subtle, but no less compelling, feel to the parks. ‘Clearing up’ is kept to a minimum, allowing the natural cycles of decay to do their work: an Amstelveen heempark may be heavily managed, but with a light, respectful touch

show a different approach where, as Hein says,‘ecology and design have been going hand in hand since the 1930s’, and where ‘plantings have to be interesting and beautiful for the public from the beginning’.Although emphasis is on natives, some nonnative species are used,such as Astilbe hybrids and groundcovering Pachysandra terminalis.The influence of Amstelveen has spread wide in the Netherlands,with a national garden and heempark network now established (see margin note, above). It is surely time the towns and cities of the United Kingdom had the courage,initiative and foresight to take a similar view of what urban biodiversity could really be.

NIGEL DUNNETT is Senior Lecturer in the Department of Landscape at the University of Sheffield NOËL KINGSBURY is a writer interested in new approaches to garden-making 215