Developing a model to describe current practice

These clusters of philosophy and practice can be represented on a gradient to describe the relationship between art and nature in garden and landscape design. The ‘nature’ end might be indistinguishable by the casual observer from the creation of ‘semi-natural habitats’, developing dynamically with a minimum of human intervention. The other extreme is represented by what could be termed ‘art’, the use of plants to supply colour or purely sculptural effects. This approach is almost completely dependent upon frequent and intensive interventions by human agency for its intended effect, and owes little to the inspiration of the natural world. The formality of the Baroque tradition as exemplified by Andre Le Notre would be a classic example.

Our interest is obviously at the ‘natural’ end of this gradient. The centre might be characterised most usefully by the ‘Twentieth-Century English School’, the Jekyll and Sackville-West influenced style which so consumately mixes clipped formality with cottage-garden insousiance. The problems of defining when the ‘natural’ or the ‘ecological’ stops and the ‘informal’ starts are legion, and are not helped by the difference in the usage of ‘natural’ and ‘naturalistic’ in the jargons of British and American English practitioners and commentators. Semantics plays a role here, as North Americans tend to interpret ‘natural’ and ‘naturalistic’ much more widely and loosely than do users of British English; ‘natural’ planting styles in North America cover any ‘informal’ style, i. e. where there is no geometrical layout or clipping and training of woody species (Lovejoy 1998).

Taking the gradient concept further, a useful way of looking at the broad range of ecological planting might be through a grid, which not only takes account of both the ‘nature/art’ equation on one axis but also of another key question in the field, that of the use of locally native plants, on another axis. Whilst this is a much more contested issue in some countries than others, its consideration does help to separate out a disparate variety of planting styles and to make sense of a complex set of philosophies (Figure 3.1).

Positions on the ‘nature/art’ axis can be defined in relation to the characteristics of natural plant communities:

– the degree of taxonomic diversity in a planted area (i. e. a monoculture versus plantings

of many species)

– the degree allowed for dynamism or spatial mobility of a taxa over time (as opposed to

the removal of any plant that spreads to a place not chosen by the designer)

– the repetition of taxa across an area

– the intermingling of taxa (as opposed to the planting of monocultural units).

Six positions can be defined as follows.

1 Formality—where highly artistic, often geometric, criteria control precise plant placing,

often accompanied by clipping and training. This position is not included in Figure 3.1.

2 Mass planting—where monocultural blocks of a limited number of taxa of wide

ecological amplitude are the defining characteristic.

3 Conventional informal planting—no intended visual relationship to natural plant

communities; individuals or small groups are placed in positions, from which they are not generally expected to move.

4 Stylised nature—a planting with an aesthetic that is recognisably inspired by wild plant

Static…… > —….. -> Dynamic

Dominant Strong Horticultural and Strong ecological Dominant

horticultural horticultural ecological influence ecological

influence influence influence influence

Role of natives

Native Conventional Species selected Colour-schemed Prairies

species only

garden

for visual impact

wildflower

meadows and

design with

e. g. Amstelveen

plantings (b)

other

natives (a)

(b)

wildflower habitats (f)

Mixture of

‘Lebensbereich’

Native/exotic

Woodland

natives and

German parks style

biotopes e. g.

with some

non-natives

(d)

Hitchmough &

non-native tree

Dunnett (c)

species

No

Mass

‘Informal’

‘Lebensbereich’

Botanic Gardens

particular

perennial

garden

German parks style

‘biogeographic

emphasis on

planting e. g.

plantings e. g.

(d)

planting’ (e)

natives, but

much Oehme

Piet Oudolf

plants with a

and Van

naturalistic

Sweden

aesthetic

commercial

used, ie, no doubles or variegation.

work

Horticultural

Conventional

Conventional

aesthetic i. e.

landscape

garden

Includes

double

flowers,

variegation

etc.

design

design

Mass

Informal

Stylised nature

Biotope planting

Habitat

planting

planting

restoration

3.1

The relationship between art and nature in garden and landscape design. Letters in parenthesis refer to categories described on page 61

communities but which is designed for visual effect, often with plants located individually by the designer. A high level of dynamism in the ongoing development of this planting, for example self-seeding, is allowed. Intensive maintenance.

5 Biotope planting—a plant community with all the dynamism of wild habitat and clearly

resembling natural habitats in terms of its structure, but whose species mix is chosen for an aesthetic effect, as well as their ecological suitability for the conditions at the site. Maintenance is generally extensive (i. e. with minimal input).

6 Habitat restoration—where the aim is to create something as close as possible to a

‘wild’ habitat, at either a climax or relatively stable sub-climax community. Maintenance is generally extensive.

In Figure 3.1, these positions are classified into three groupings: those that are strongly influenced by ecological principles and aesthetics (‘Biotype planting’ and ‘Habitat restoration’), those that are strongly influenced by more traditional horticultural aesthetics (‘Mass planting and ‘Informal planting’), and those that are highly influenced by both horticultural and ecological ideals (‘Stylised nature’). There is a tendency for levels of maintenance to tend to become lower as one moves from mass planting through to habitat restoration, although mass planting is frequently an exception in that the plants selected are generally selected to be ultra-low maintenance. Maintenance increases with the increase in the ‘unnatural’ nature of the planting, but a further reason is an aesthetic one; the more ‘naturalistic’ plantings are better able to visually ‘carry’ unwanted weedy species, as they are less prominent (Hitchmough 1995a).

The ‘native species contents’ axis can be defined by the following stops on a gradient.

1 The use of only plants that are ‘native’, defined with reference to a region of greater or

lesser size (often a nation state, arguably an inappropriate way of doing so).

2 A mixture of natives and non-native ‘exotics’, often with the former preponderant.

3 The inclusion of species ‘exotics’ and cultivars of wild origin, but all of which maintain

the proportions of wild plants.

4 The inclusion of taxa which are essentially horticultural and ornamental, such as

complex hybrids, cultivars with variegated foliage or double flowers, etc.

Referring to Figure 3.1, the area represented by the bottom-left corner covers conventional horticultural and landscape planting design. There are, however, a certain number of practitioners whose work clearly belongs here, such as Piet Oudolf and the Oehme Van Sweden Partnership. They do not use native plants and cannot be said to be ecological, but employ certain naturalistic aesthetic elements in their work, and are seen by many as belonging to the ecological camp. Perhaps most importantly, their work is widely seen as being part of ‘ecological design’ as a cultural phenomenon. This work is covered on the section ‘Evolving nature’.

The top area (a) of Figure 3.1 refers to an artistic, and not particularly ecological use of native plants, rarely seen, but possibly increasingly important in areas where there are strong pressures to use native material, such as the US. This is covered later in the section ‘Native flora as an artistic medium’. Habitat restoration is not really the subject of this account, but it can have an important role in designed environments, discussed in the section ‘Habitat restoration and beyond’. Plant communities may be modelled on nature, but with a greater or lesser design input; these are covered by (b) in Figure 3.1 and in the section ‘New native plant communities’. The introduction of non-native elements into native dominated plant communities (c) is the subject of the section ‘Biotype planting— adding exotics to native vegetation’, whilst the creation of nature-inspired, but still quite ‘artificial’ plant communities, such as the German Lebensbereich style (d) is the subject of the section ‘Stylised nature—German Lebensbereich plantings and others’. As can be expected, many practices do not fit neatly into these boxes. One reason for this is that one practice or location may include several different approaches to planting design that grade into each other. The plantings in the parks of Amstelveen in the Netherlands are a good example, varying between pure habitat restoration on the one hand and an ‘artistically driven’ management of native species on the other.

‘Biogeographic’ planting (e) is a highly specific form of ecological planting design, and largely falls outside the scope of this text. A relatively recent trend in botanical garden design, it aims at as complete a representation of a natural plant community as possible, so, for example, the visitor might move from recreated Ukrainian steppe to Anatolian meadow to Caucasian forest in a hundred metres. The Botanic Garden at Bayreuth University, established in 1975, is a fine example, where each area leaves the visitor with a powerful impression of having landed somewhere completely different (Kohlein 1992).

Finally, it is worth mentioning one further form of ecological ‘planting’, that also belongs on this grid shown in Figure 3.1, sharing (f) with habitat restoration. This is that of ‘spontaneous’ vegetation development, where post-industrial areas develop their own vegetation through natural processes, and where a design decision may be made to keep the resulting vegetation. Allowing land to support a series of successional communities in urban areas often results in a very distinctive mixture of native and introduced species. Whilst the value of wildlife to such areas is widely appreciated, their aesthetic value rarely is. Austrian landscape architect Cordula Loidl-Reisch is one of the more articulate proponents of the aesthetics of this process of growing wild—Verwilderung. Her writing, however, reflects a perspective that is philosophical and theoretical rather than practically orientated (LoidlReisch 1986, 1989).

In this chapter we will review the various strands of contemporary ecologically – informed planting design. We will start at the predominantly ecological end of the spectrum (i. e. to the right hand of Figure 3.1) and will finish at the strongly horticulturally-influenced end of the gradient (i. e. the left hand). At each point we will consider relevant philosophical and practical issues that currently dominate the application of ecological ideas in designed landscape and garden plantings.

Developing a model to describe current practice

3.2

The trial grounds at Weihenstephan, at Freising near Munich, are home to extensive collections of perennials but which are arranged in a naturalistic style, key plants being repeated to create a sense of rhythm. Mauve Salvia verticillata and deep yellow Achillea filipendulina are prominent here (July)