Naturalistic plantings at Denver Botanic Gardens

If you’re used to order in the garden, naturalistic plantings can seem a bit out of control. But installations such as New York City’s High Line are bringing this new, plant-driven approach more and more into the mainstream. That’s according to award-winning designer Carrie Preston of the Netherland’s Studio TOOP. She spoke recently in Maryland on how to incorporate naturalistic plantings into all types of landscapes.

Towards a new way of thinking

For Americans who are just beginning to accept this looser form of design, Preston’s style is unabashedly natural and almost wild to unaccustomed eyes. It evokes the feel of a real landscape. Or as Preston puts it:

‘Nature as we all dream it would be.’

She calls this style a kind of hyper nature. And she credits Dutch garden designer Piet Oudolf, creator of the High Line, with launching the movement. A leading figure of the ‘New Perennial Movement’, his designs use bold drifts of perennials and grasses in sustainable, naturalistic plantings that teem with biodiversity. 

Naturalistic design by Piet Oudolf

‘Stylized naturalistic gardens like the High Line have accustomed the public’s eye. Now we can move further with more dynamic biodiversity.’ she said. ‘If we can show that it’s deliberate, people can accept it. Step by step, naturalistic advocates are training the eye to see what’s beautiful.’

New York City’s High Line

Why biodiversity is important

Why is biodiversity important? Because it is sustainable. Naturalistic plantings are not only more drought-resistant, they help control invasive species while keeping maintenance and chemical needs low.

Until recently in America, the tendency has been to go all out in one look. The Dutch, by contrast, marry different styles in one garden. They have no problem contrasting differing historical perspectives with more wild plantings. 

So how do you make naturalistic plantings appeal to viewers who are accustomed to a single look? Or as Preston puts it, make them legible? It all starts with structure.

Clear structure tames naturalistic plantings

Successful gardens are all about balance. And a clear structure is essential to supporting and creating contrast to unstructured, naturalistic plantings. Hard landscape materials and clear lines keep the viewer from getting overwhelmed. 

One has only to look at the Dutch countryside, where drainage ditches are an iconic feature of the landscape. Long lines are part of the collective unconscious. Even the famous Dutch painter, Piet Mondrian, reached a point where his art was reduced to simple geometric elements. “You learn to love lines here,” Preston said.

Drainage ditches are an iconic feature of the Dutch landscape

Preston uses strong lines to punctuate the landscape and add ‘anchors for the eye’ so the rest of the stuff can do what it does naturally. She advocates establishing clear lines with patios, walls or walkways, then blurring them with wispy, cascading plantings.

‘Think of structure as the lines in a coloring book, then color outside them,’ she said.

Below, hard lines soften wispy plantings in this simple design by the late mother of modern Dutch garden design, Mien Ruys. 

Photo: Monument | Tuinen Mien Ruys

A clear hardscape and strong structure also make messiness seem deliberate. Preston often imagines a garden as totally paved. Then she takes parts out and adds back in the plantings. ‘It’s not about what you use, but how you use it’, she said.

Studio TOOP design/Photo: Association of Professional Landscape Designers (APLD)

Vertical lines attract the eye

Vertical elements help to break up the view and lead the eye around the garden. According to Preston, they also help unify a design and ‘contain’ the exuberance of naturalistic plantings. Vertical elements can be massed trees, hedges, architecture or art. They can even be functional features like lamp post lights.

Below, a section of Washington, DC’s Federal Reserve Board Garden designed by Oehme van Sweden exhibiting strong verticals and the aforementioned long lines. 

The Federal Reserve Board Garden/Photo: The Cultural Landscape Foundation

A limited palette enlarges the space

Most Dutch gardens are tiny, averaging about 600 sf. To make designs more effective, Preston recommends limiting the palette to visually enlarge the space. ‘It’s all about the palette, it’s not about the palette’ she quipped.

A naturalistic garden can be scaled up or down. It all depends on what plantings you choose and your attention to details. By combining different textures, mixing the familiar with the exotic and keeping the color palette simple, you can make a small garden appear much larger. Preston likes to use one plant to hold the composition together. She calls this the ‘dough’. 

‘Grasses work great for this,’ she said.

Below, foxtail lilies provide the ‘dough’ and the sculpture serves as a vertical at the Denver Botanic Gardens. 

Many point to the revolutionary landscapes created by Wolfgang Oehme and James van Sweden as the epitome of this kind of garden style. Characterized by broad strokes of naturalistic plantings, they include fields of perennials and grasses. Instead of the usual 5 or 7 plants, though, the groupings sometimes consist of as many as 3,000. Large swathes of same species enlarge the space visually, while repeated patterns help create rhythm and flow. 

Naturalistic landscape designed by Oehme van Sweden

Another plus is that, no matter what the size, naturalistic landscapes remain interesting all year round. In the winter, dried grasses turn a beautiful burnt gold and faded seed heads serve as receptacles for the first flakes of snow.

Great plants for naturalistic landscapes

Here are some common grasses and perennials that make great naturalistic plantings:

Amsonia (Blue Star)

Baptisia australis (Blue False Indigo)

Cranesbill (Hardy Geranium)

Echinacea purpurea (Purple Coneflower)

Feather Reed Grass

Helenium autumnale (Sneezeweed)

Liatris spicata

Miscanthus sinensis (Maiden Grass)

Rudbeckia (Black-Eyed Susan)

Sedum ‘Autumn Joy’

Preston grew up in NJ but moved to Holland. Over the past 10 years she has become one of the Netherlands top landscape designers. In 2016, she received the Association of Professional Landscape Designers (APLD) Designer of the Year Award for her ‘Inclusive Garden.’