The expansive meadow at Longwood Gardens, Pennsylvania is in fact a relatively recent (1969) creation, built on what was previously farmland. It perfectly captures a feeling of abundant growth and wide open space and provides a home for a rich diversity of animal, insect and plant life.
Gras ist das Haar der Mutter Erde.
(Grass is the Hair of Mother Earth.)
—Karl Foerster
THE SAVANNAH OF Central Africa, the veldt of South Africa, the pampas of South America, the prairies of North America, the steppes of Asia and the meadows of Europe: all of these great grasslands exist (or used to) on a vast scale, covering square mile after square mile. Yet even when planning the smallest of domestic gardens, we can learn much from these great grasslands. Understanding how they are naturally composed, and tuning in to the spirit they evoke, can help us to imbue our own gardens with a pleasing sense of informality and longevity through the use of grasses.
To the casual eye, from a distance, these fabulous natural grasslands may look like monotonous (or even relentless) virtually uninterrupted expanses of ‘just grass’. In reality this is far from the truth; like all successful communities, they are extremely diverse. The great grasslands evolved, sometimes in tandem with human civilization, to become distinctive ecosystems with their own specially adapted flora and fauna. Many so-called traditional garden plants have their roots in wild grasslands; poppies, those most beloved of garden flowers, hail from European meadows while golden rod, cone flowers and rudbeckias, which we have come to grow and love in our gardens, are denizens of the American prairie.
Roberto Burle Marx, the eminent Brazilian landscape designer, is credited with coining the phrase ‘less is more’. Perhaps a natural grassland provides the perfect example of what this might mean for our designed spaces: a restrained palette of plants used in bold but sensitive ways can give an arresting feeling of place and space, of nature and of control. When seen in the wild, grasses’ striking ability to define a mood and bring fluidity, movement and harmoniousness to a space explains why they work so well, on a smaller scale, in our designed gardens. It is precisely these qualities that our gardens so often sorely need.
On Evening Island at the Chicago Botanic Garden, the simple and refined use of a few well-chosen grasses on a massive scale is truly breath-taking. As the island’s name suggests, the plantings where designers Wolfgang Oehme and James van Sweden have used Miscanthus, Molinia and Panicum are doubly effective each evening when low sunlight illuminates the countless grassy flowerheads. Here individual grasses are used in very large swathes. The garden is just one example of many successful ways in which we can draw inspiration from natural grasslands.
Grassland actually comes in all shapes and sizes, and can be found in many regions. The tall grass prairie is aptly named with much of the constituent plants growing to above head height. The grasses making up the European meadows and much of the steppes, on the other hand, are somewhat shorter. Thick, rough Cortaderia can make travel through South America’s pampas anything but comfortable, and the savannah and many mediterranean grasslands close down during the heat of summer, going into dormancy until the essential life-giving rain arrives in autumn.
This wonderful Oehme and van Sweden planting on Evening Island at the Chicago Botanic Garden borrows freely from the grassland ideal, using miscanthus to create seemingly endless flowing swathes through which thread numerous paths and trailways.
Acid, alkaline or serpentine; pure sand to solid clay; freezing cold or baking hot; dust-dry to distinctly wet: anywhere that has sufficient sunlight will mostly have its associated grassland community. And in no small measure it is this ability to survive and prosper under such a broad spectrum of conditions that makes grasses so desirable in our gardens.
The term ‘meadow’ has been applied to an area of predominantly grass (or grass-like plants) which without intervention, human or otherwise, would eventually end up becoming woodland. This is known as being ‘in transition’, the natural process of moving from open ground to mature woodland. Contrastingly a true grassland is one where trees cannot grow due to one or more climatalogical factors such as lack of water, leading to more or less permanently open grassland.
High on Figueroa Mountain in California, a meadow of Elymus elymoides survives on an area of serpentine soil which the alien grasses, seen covering the background slopes and which were originally introduced to improve grazing, have difficulty penetrating.
A prairie is an example of a permanent grassland community (although apparently the word ‘prairie’, bestowed by early French travellers, actually means ‘meadow’ (according to Christopher Lloyd’s Meadows). The word ‘prairie’ has become evocative of wide open spaces; more recently it has come to connote a style of planting which, in much of its detail, can bear little resemblance to the original. Being good for farming, huge tracts of prairie land in the United States have been converted to the extent that the term ‘prairie remnant’, used to describe what is left of these once-mighty grasslands, is now all too apt. These permanent grasslands have clearly not benefited from human intervention.
By contrast, Ferndown Common in Dorset, England is an example of an impermanent grassland that has benefited directly from human intervention. Although trees could thrive there, the area was cleared by early human activity of much of its tree cover sufficiently long ago for a specialized community of plants, including grasses, to have evolved, taking advantage of the open ground. Purple moor grass, Molinia caerulea, is now abundant but still relies on periodic human intervention to clear trees and scrub for its continued success.
From a gardener’s viewpoint, while such name tags as prairie or meadow have some practical value for describing planting styles, these labels can be counterproductive if taken too literally or out of context. A true North American prairie is no more likely to feel at home in a European urban garden than an authentic English meadow will be happy in a mediterranean Californian backyard. Both types of grassland have evolved in response to a specific place and a given set of conditions; changing the place or the conditions inevitably affects the outcome. While an accurate recreation of a natural grassland, also sometimes known as a ‘restoration’, can have great merit (see Chapter Seven), it is really only practical in places that those individual communities once called home—so try not to have unrealistic expectations for your own grassy garden. Rather than trying to emulate every detail of natural grasslands, gardeners and designers should draw inspiration from their overall effect, feel and style.
Locally native purple moor grass, Molinia caerulea, creates a warm winter brown carpet in association with darker-coloured heathers and a background of pines, birch and oak on Ferndown Common in Dorset, England. The ancient demand for timber led to the felling of the forest, allowing the molinia to colonize the newly open spaces. Even today, such grasslands still rely on human intervention to prevent woody plants from claiming back lost territory.
In landscaping a private home in Monterey, California, Bernard Trainor used purple three awn with other native grasses to help anchor the site within the surrounding natural landscape.
California native Aristida purpurea has reddish purple flowers that gradually dry in the summer heat to a light beige-brown that visually links with the surrounding hillside.
To reinforce this link, even some of the flanking walls are finished in a sympathetic colour and surrounded by the same mix of grasses, with an occasional non-native such as the taller purple Calamagrostis ×acutiflora ‘Karl Foerster’ for accent.
The purple three awn is encouraged to come right up to the house, or at least to the parapet.
THE GRASSLAND PRINCIPLE Despite wildly varying local environments and prevailing conditions, all grassland communities owe their characteristic air—perhaps, indeed, their charisma—to their shared feature: a preponderance of grasses, with their characteristic linearity, in a generally open space. To evoke the spirit of natural grasslands in our own gardens, then, we should make grasses a key element of our planting design. But this is not to suggest that only grasses should be used in natural-grassland-inspired designs; while there is certainly enough shape, form, colour and contrast within the group to make a grasses-only planting very effective, in practice this style is more often seen in botanical establishments. One example is the impressive Grass Garden at London’s Royal Botanic Gardens Kew, where the comprehensive collection has both an educational and a design ethic. In private gardens, contrastingly, I suggest following what I call the Grassland Principle: grasses should comprise twenty to eighty percent of the overall planting palette.
Look in detail and you will see that grassland composition is a mix of not only different grasses but also bulbs, annuals, perennials and woody plants. Grasses provide the basic layer (or ‘matrix’) but the other plants also have vital roles to play.
Woody plants provide structure, screening and colour from flowers, leaves and stems. Interest at a lower level comes from all manner of bulbous plants in the spring, followed by a plethora of different perennials, many originating from grasslands, such as Rudbeckia, Echinacea, Helenium, Monarda and Aster which provide a seasonally varying succession of colour and interest. All of this is framed and supported by the grass layer.
As Ferndown Common and its fabulous man-maintained grassland of Molinia caerulea is in fact only a few hundred yards from the garden at Knoll, we have drawn inspiration from it. Being native to the area, Molinia grows well in the sandy soils of the garden where we have used it as a base and a foil for other more solid companions such as the perennials Eupatorium ‘Chocolate’, Echinacea purpurea ‘Ruby Giant’ and Sanguisorba officinalis ‘Pink Tanna’. Woody plants are represented by some dark green conifers, yew and viburnum which provide a backing and a screen from another part of the garden, while early-season bulbs such as daffodils and camassia provide early colour before the grass has regrown. The whole area measures only about 25 square metres (30 square yards), excluding the backing woody plants, and while the molinia in this case makes up something like sixty percent of the actual area, its effects are counterbalanced by the larger perennials and the woody plants so that the border is far from being ‘just grass’. Nonetheless, this grassland-inspired area, designed to work in harmony with the garden’s conditions, has the effects of grassland: a distinctive linearity, a preponderance of grasses, the feeling of open space.
While admittedly lacking more traditional flower early in the season, grass-only plantings can achieve a spectacular level of interest from high summer onwards—especially when many different grasses are used in the same area, as at the RHS Garden Wisley.
On a different scale, at Scampston Hall in Yorkshire, master designer Piet Oudolf has again used Molinia caerulea, this time in a selected form Molinia caerulea subsp. caerulea ‘Poul Petersen’, in a design that blends a grassland approach with the formality often encountered in more traditional larger gardens. While the individual beds are one hundred percent molinia, this is balanced by other more formal elements such as lawn grass and hedging, greatly reducing the percentage of actual ground covered by the molinia. Although very formal in layout, much of the design’s ‘wow’ factor comes from the simple use of a native grass planted in large quantities.
An excellent form of purple moor grass, Molinia caerulea subsp. caerulea ‘Poul Petersen’, is used to breathtaking effect at Scampston Hall, Yorkshire, in a modern interpretation of the grassland effect by master designer Piet Oudolf. Photograph courtesy of Alexandre Bailhache.
It is easy to understand how the Grassland Principle works by looking at larger areas like Scampston Hall and Evening Island at Chicago Botanic Gardens, where grasses are used in bold swathes to cover significant areas of ground. But can the Grasslands Principle work in much smaller spaces? The answer is a simple ‘yes’.
Our gardens are typically composed of a varying mixture of borders, hedging, pathways and lawns. On a larger scale, each of these different areas is big enough to work well on its own. But on a more diminutive scale, borders are often too small to contain any depth of planting, lawns simply cumbersome to cut and too small to be useable, and shrubs and hedges sometimes clipped into formless and deeply uninteresting shapes. In other words, dividing a small outdoor space into separate sections often means that the whole area risks becoming virtually worthless; we expend time, energy and precious resources on something that gives little pleasure or even basic satisfaction. A new approach is needed, and adopting the Grassland Principle provides the practical solution.
Rather than focusing on its subdivisions—borders, hedging, pathways, lawn—think of the small garden as a single area that has several different jobs to do. Merge the lawn space with the border area using a basic ground layer of grasses and a mulch layer through which can come all sorts of plants from early spring bulbs to floriferous perennials and woody shrubs to provide permanent shape and screening. We readily carpet or otherwise cover the floors of our interior living spaces, mostly in a similar single material, from wall to wall—and there is little reason not to do the same outdoors. Pathways can simply be spaces left between the plants, and sitting areas can be almost anywhere and moved as the garden changes. Not only will the same area be much easier to maintain, but it will also be of significantly greater value to wildlife, and infinitely more pleasing to the gardener.
• Grasses should comprise 20–80% of the total number of plants used in the garden mix. If selected carefully, a higher percentage (50% or more) can provide the greatest ‘wow’ factor, strongly evoking the spirit of grassy meadows or prairies. A lower percentage of grasses is useful as a theme or backing to other plantings such as with perennials.
• When using a higher percentage of grasses, choose a restrained palette of 1–5 different grasses as a basic mix or ground covering. A larger number of different grasses can subsequently be used as accents or highlights of the remaining planting. (However, more than 5 species of Carex may be used together as a ground pattern as their overall shape can be quite similar.)
• Avoid using too few specimens of the same plant in one place. Grasses almost always work best when planted in larger numbers, whether placed as a drift meandering through a grassy space or en masse as part of a larger planting.
• Go large. Make the planting area as big as possible; the larger the area, the greater the grasses’ effect. Small borders are always more work and less effective. Merge smaller borders with lawns to make more planting space.
• Pathways and sitting areas should be an integral part of the planting, rather than separate from it. For low-use pathways, simply leave sufficient space between the plants for people to walk through. Using a similar material as surface mulch for the planting areas and the walkways gives a great sense of space and is easier to install.
• Woody plants and perennials are essential to most successful plantings. Choose woody plants for year-round effect, bark and leaf colour and for permanent screening. Choose perennials that provide flower colour and form, ideally those that maintain their shape after flowering to provide long-term contrast with grasses. Such perennials include Echinacea, Eupatorium, Persicaria, Rudbeckia and Sedum.
• All manner of bulbous plants can be used to provide early-season colour, especially with deciduous grasses which are at their least interesting in the spring. Bulbs are usually added in the autumn wherever a space is suitable.
• Prepare the ground before planting. Grasses are no different from other garden plants in that reasonable soil conditions will ensure best growth and establishment. However, unlike many garden plants, grasses do not need much fertilizer or water once established. Ensuring that the ground is not compacted and laying a surface mulch after planting are perhaps the two most important elements of preparation.
