Wild-ish at Heart: Naturalistic planting design

It’s about setting aside our desire for control to instead work in partnership with nature. This is essentially the guiding principle behind the naturalistic garden, a plant-driven approach to landscape design that has been around in one form or another since Englishman William Robinson first published his first edition of The Wild Garden in 1870.

But now with signature projects like the High Line in New York City and Chicago’s Lurie Garden, a growing global movement in planting design has found a bolder, modernist expression of this ideal with a collective dream to re-wild our nature-deprived urban worlds.

It’s one thing to marvel at the High Line, with its ecstatic sweeps of perennials and grasses as envisioned by Dutch garden designer and plantsman Piet Oudolf, but for home gardeners, the question is, How can I bring something of this wild spirit back to my own urban garden reality?

I once wondered the very same thing. After years of experimenting in my own northern perennial garden and getting to know some of the plants and people leading the charge, I became seriously inspired to find a way.

Allow me to share some ideas to help guide you on the path less manicured.

Inspired by nature. Attuned to ecology. Do try this at home.

The naturalistic ethos is about creating a multi-purpose garden with the amplitude to feed the soul and nurture local biodiversity. It seeks to minimize typical garden inputs like pesticides, herbicides, and fertilizers, while recycling its outputs from rainwater to garden waste, all in the name of self-sustainability.

This approach to design can work in virtually any kind of garden context or style, whether the hardscape is formal, cottage or contemporary. In fact, juxtaposition is your friend. Or, as Mien Ruys, the late mother of modern Dutch garden design, put it: “Wild planting in a strong design.”

Scale up. Scale down.

A naturalistic style can be scaled up or down as needed, from the open expanse of a lawn-free front yard to a mere window box. Mind you, the smaller the scale, the more finely tuned the nuance and detail of plant selection and positioning become.

Ecologically speaking, the natural garden is adaptable to almost any kind of ecosystem; a core principle is to group plants together by common habitat, be it woodland, prairie, wetland or steppe. A smaller garden is more like a micro-habitat, where everything starts with the setting itself. The more you know about your existing site and its conditions (light, soil, pH, moisture, hardiness zone, etc.), the more successful your future design and planting decisions will be.

A new way of seeing

The current fascination with naturalistic style can be traced in part to the rise of the so-called New Perennial movement in planting design. This movement originated over 30 years ago in the Netherlands as an iconoclastic group of designers, plantsfolk, artists, and philosophers with Piet Oudolf emerging as its leading figure.

The New Perennial approach is about opening your mind’s eye to see plants for more than simply the beauty of their flowers. Philosophically, it’s about embracing change in the garden and the interplay of textures and foliage from birth to bloom and from decay to death. This quietly revolutionary aesthetic underpins a four-dimensional approach to design with the plantings composed like a living art form, designed to evolve in space and time.

In public plantings, what may appear to be spontaneous is, in fact, highly orchestrated, planned and considered as part of the designer’s vision. In your own garden, there are no such rules: Feel free to experiment. The joy of working with perennials and grasses is that once planted, you can always tweak, edit and revise your designs over time. We learn by looking. And in many ways, the best teacher is the garden itself.

Rooted in plant selection

The aesthetic of the New Perennial garden is rooted in plant selection with an eye to both ecology and design.

The visual emphasis is on structure and form rather than colour, because structure can persist over the entire growing season, while flower colour comes and goes. The preference is for perennials closer to the species, with a wilder character and a more proportionate leaf and stem to flower ratio than over-bred cultivars.

The aim is to select proven, long-lived, robust plants capable of performing strongly in various garden conditions. Extra marks are awarded for persistence in form and seed head, or, as Oudolf says, “Plants that die elegantly.” Indeed, a whole other colour palette comes into play in fall and winter with straw, brown, charcoal and rust.

Particular attention is also paid to how each plant grows from the roots on down—whether it clumps or runs, and how well it responds to stress and competition. Every detail of a given plant’s habit provides a clue into how well it plays with others and what ecological niches it can fill.

In his search for an expanded plant palette, Oudolf assembled and introduced a number of initially obscure perennials and grasses that fulfilled these criteria. Over the course of 30 years, he developed a signature perennial palette of plants that he could trust to behave as “good neighbours.”

The shape of things

For purposes of design, Oudolf encourages us to think of the herbaceous kingdom as a series of spires, globes, daisies, buttons, spikes, plumes and umbels, as well as the textural effects that various plants can create, from a solid screen of ornamental grasses to a transparent curtain of grasses, depending on the species and where they’re sited.

The goal is to free the mind to think in the abstract when combining plants and to aim for a variety of shapes and effects in the course of one planting area. It may also gently steer the gardener away from the temptation to plant one of this and one of that with no sense of connection.

As Roy Diblik, author of The Know Maintenance Perennial Garden reminds us: “One plant is just a single note; no matter how beautiful on its own, it needs other notes to form a melody. That’s where the real music can begin.”

Plants with purpose

The next part of the equation is to consider the role a given plant species might play in your garden ecosystem. What is its benefit to wildlife? Does the plant serve as larval host for any particular insect? Do its seed heads benefit foraging birds in winter? The list is long and deep.

These are all things to keep in mind but ultimately, it’s not just about the plants or their provenance. It’s about how you put them all together to create a diverse garden habitat capable of nurturing a wide diversity of creatures. And yes, that includes the gardener too.

Designing in layers

The naturalistic garden comes to life using the ecological principle of layering.

Most natural habitats are made up of a series of planting layers. For example, a typical woodland consists of at least three layers: the upper tree canopy, mid-shrub understorey and lower ground layer.

This key principle of multiple layers—where plants are grouped by common habitat in proportionate layers to create a dynamic plant community—is essential to the design process, as shown in this diagram from the book Planting in a Post-Wild World.

In a typical home garden, there are generally four or five layers to consider when assembling a plant list and creating a naturalistic planting design. This image of my former uncottage garden reveals the principle at work in an open sunny raised bed.

• structural layer: trees, shrubs, taller perennials and grasses
• companion plant layer: mid-size theme plants
• groundcover layer: works like a living mulch to suppress weeds, retain moisture, and thereby eliminate the need to apply store-bought mulch to bare soil
• vertical layer: vines and climbers to run up fences, shrubs, and trees
• filler layer: short-lived plants and bulbs scattered throughout to add spontaneity and seasonal interest

Another way in which a naturalistic design is different from other planting styles is that instead of planting in monocultural blocks, perennials and grasses are freely intermingled in single and small groups to create natural-looking drifts and repeated patterns throughout the entire planting area. The idea is to let one grouping flow into and past another to give the feeling of spontaneity.

The layers are planted to knit closely together to cover any open ground, suppress weeds and support invertebrate life. The ideal is to create contrast with a mix of coarse and fine foliage in the layers. Even in a small garden, go for size and scale; too many small plants can read as fussy.

Ready. Set. Grow.

To naturalize an existing garden, you can start off slowly. Simply change up your maintenance regime to influence the look of your plantings. Leave seed heads to form instead of deadheading. Rather than cut everything back in the fall, let plants stand for the winter and enjoy their silhouettes. In every such decision, wildlife benefits from our not-doing.

Experiment with some wilder-style plant choices like umbellifers (e.g. Achillea, Astrantia, Eutrochium, Zizia) that speak to your aesthetic and suit your conditions. Introduce specimen grasses, a skirt of sedges or ferns into the heart of your plantings to create a wilder look. Edit existing plantings to create more random and less predictable patterns.

If you have a blank canvas, start by choosing a mood or theme for your new garden. That choice invariably influences all your other decisions, from the hardscape to the plants you select. Position your plantings for prime viewership, whether from inside your home looking out or from wherever you plan to spend time in the garden itself. You’re using plants to create a vibe, an atmosphere, and to invite the outside in.

On a smaller scale, the plantings can become parts of a stage set. Try to repeat theme plants and combinations to link one part to another. Pay special attention to how natural light moves through the garden space to illuminate the plantings.

Get out into the world and visit public gardens that follow a more naturalistic approach. Or just get lost in nature and find your muse there.

Have patience and give it time. When your home garden starts to appear as if it has grown all by itself, you’re definitely on the right (less manicured) path.

==

Next time: Part Two: Naturalistic Garden Hacks

This post originally appeared in the Spring 2017 theme issue of Garden Making magazine.

Resources: