Supernaturalistic: The New Perennial Pond Garden

At its roots, the New Perennial movement in naturalistic planting design is about making gardens in symbiosis with nature. It calls for a wilder aesthetic, attuned to ecology, and informed by horticulture.

Inspired by naturally occurring habitats, such plantings are designed landscapes composed of a series of interwoven plant layers together forming a community, abstracting the patterns and rhythms found in nature.

Our pond garden exists as a portal to nature, a river that flows both ways.

There are no rules, only guidelines for the home gardener: Reduce garden inputs, recycle garden outputs; design with biodiversity & maintenance in mind; group plants by common habitat; work with the conditions you got; invite spontaneity; use plants as a living mulch to cover ground; come fall, leave plants to stand and amend in their own debris; above all, experimentation is the key to learning.

With all this in mind, welcome to my 2020 version of Wildscaping at home.

Myth busting

Let me explode a few myths right off the top. Firstly, that the New Perennial style only really works in full-sun meadow-style plantings like The High Line or Chicago’s Lurie Garden, seen here.

Echinacea pallida (pale coneflower) splays into glory at the Lurie Garden in late July. All plants part of a greater composition abstracted from art and nature.

Dutch godfather of the movement, Piet Oudolf finds this oddly amusing because while he appreciates the public response to his prairie-inspired work, he’s equally adept at designing shady woodland plantings or whatever else comes up on his plate. His recent project for iconic restaurant Noma in Copenhagen featured pop-up plantings using a design palette of edible grains and annuals.

There’s also the notion that this plant-driven approach for public space does not translate well to small home gardens. To this, Piet shrugs and responds that it’s simply a matter of scaling down the numbers of plants and groupings; the same basic design principles and plant relationships apply, albeit with a finer eye to detail.

My own experience supports it: I spent well over a decade experimenting with the New Perennial approach in a smaller-scale uncottage garden with diverse microhabitats in sun and shade and it evolved way beyond expectation.

The spring un-cottage garden: Anemone sylvestris (snowdrop anemone) and Geum triflorum (prairie smoke) up close with our neighbours, an exquisite octagonal wooden church looming in the background.

In my first design project at our log cabin on the Niagara Escarpment here in Ontario, Canada started in 2015, I’m working on a far bigger and more complex canvas with a mix of shady woodland edge, riparian meadow, and a small bog to boot, all on the western bank of our one-acre pond. 

Pond Life: Planning + Process 

It’s fair to say my pond garden is the apotheosis of everything I’ve learned to date, culled from all my experience, reading, travels, and conversations.

My plans and plant lists have been crazy ambitious, all to create a supercharged slice of woodland garden plugged into the greater ecosystem here. Of course, much like writing, none of that ambition should be visible in the garden itself.

Phlox divaricata and Adiantum pedatum blooming in spring pond garden
A perennial matrix planting blooms in the spring pond garden – comprised of Phlox divaricata ‘Blue Moon, Adiantum pedatum (maidenhair fern) and Tiarella wherryi (foamflower). Aster divaricata (woodland aster) with its dark stems spills into flower from late summer into fall.

This project started in my imagination – brainstorming to find a theme for the garden. I wanted something wild-ish, otherworldly, unexpected: a hidden place with a charged atmosphere connected to the greater scale of pond, forest, sky.

On a parallel track, I conducted a site analysis to understand the local ecology and conditions: 

Mono Habitat Profile

  • Habitat: Riparian woodland edge
  • Projected Planting Area:  Approx. 120 m2
  • Hardiness Zone: 4b with ample winter snowpack
  • Light: Facing east and southeast. Part sun to dappled shade
  • Soil: Organic content 7.8 (high) Dumfries loam
  • Moisture: Transitions from dry upper slope to moist to saturated soil
  • PH Level: 7.6 (moderately alkaline)
  • Local Wildlife: Rich insect life, dragonflies, amphibians, birds, waterfowl, bats, beaver, muskrat, porcupine, mink, coyote, fisher, rabbit, squirrels, raccoons, voles, and the occasional deer

Seeking to balance ecological and thematic factors, I spent the better part of a whole winter researching my dream plant list while wondering how to develop a series of interlaced plant communities.

Actaea racemosa
The white rocket spires of another woodland native Actaea racemosa (black cohosh) are right at home on the upper slope of the bog garden.

The Oudolf effect

I was fortunate to have a ringer in the wings.

I’ve long admired how Piet Oudolf artfully juxtaposes the wilder and more controlled elements of his plantings – the presence of one amplifying the degree of the other. I’d traveled to the Netherlands in summer 2013 for a masterclass design workshop with Piet and Nöel Kingsbury at Hummelo. The experience changed my life and we became good garden friends.

When I later mentioned to Piet my plans for a new garden, he kindly offered to advise me, should I wish. It was impossible to refuse such an offer and so, after weeks of working up a succession of plans on tracing paper, I emailed the best of them to Piet in Hummelo for what he called “a proper look”.

My initial plan contained three different matrix plantings situated to match varying moisture levels down the slope along with a succession of bloom times from spring till fall. The matrices were contrasted by tall blocks of waterside perennials and a bog garden.

Over a two-hour Skype call, we discussed my plans in detail, which turned into a far-ranging conversation about Piet’s design evolution, current projects, and of course, plants.

It switched another light on in my brain – allowing me to see beyond combinations and clusters to visualize a bigger picture – how entire areas of the planting can interrelate, like islands in a matrix stream. Piet emphasized the power of restraint, to open up sight-lines and lower the plant heights through the heart of the garden to create the feeling of greater space.

My initial drawings were perhaps overly neat and polite. Where I’d drawn clean lines between sections, he suggested to blend one matrix into another to emulate the intermingling found in natural habitats.

After our chat, I reworked my drawings from scratch. The next version was still wildly ambitious but with a new sense of flow. When I sent it back to Piet for review, his overall comment was – Fast learner!

Matrix stratagems

Typically, a matrix planting consists of one or two quiet grasses, ferns or perennials to form a tightly knit base layer through which the rest of the planting can emerge. It’s an incredibly useful base approach adaptable to virtually any scale garden. 

Piet Oudolf-designed grass matrix using Sesleria autumnalis with spikes of Liatris (gayfeather) and scattered Echinacea ‘Fatal Attraction’.

I put my own spin on it to create a complex succession matrix – using 4-6 different plant species, modelled on the principles of plant sociability and succession.

Much like people, plants are social beings. Some are loners, while others love company.

The idea of plant sociability revolves around how different plants occur in their native habitat – whether as solitary specimens, in small random clusters, mid-sized groups, or larger colonies. In each instance, the plants are completely adapted – everything from roots, to foliage size, and flower – to collectively fit a specific niche within a greater community and ecosystem.

For planting design, sociability provides a major clue towards effectively using a given plant consistent with its nature – and also how to integrate related species of plants within the same plant community.

The idea originates in German ecological theory but there’s an aesthetic aspect as well. A given planting will simply look and feel more natural when you’ve done your homework on how various plants prefer to grow together.

It also takes into account how the members of a given planting will fill in and grow into each other over time.

When developing a matrix involving multiple species, it’s helpful to think in terms of ratios based on sociability and how the various plants will compete amongst themselves. Piet Oudolf will often note the matrix ratios in his plans; for example, a shady woodland matrix might be roughly 40% ferns: 25% sedges: 35% ground layer perennials (BTW: He would specify all the actual plant choices.)

Planting for succession

The second part of the equation is succession to ensure multi-seasonal interest – how you can stage the planting to perform and flower throughout the growing year. It’s a core aspect of not only more traditional garden styles but ecological science as well.

In my own woodland setting, there is an emphasis on spring bloomers but I also want to have something else going on throughout the summer and into the fall.

For example, my shady woodland matrix running down the slope is comprised of intermingled clusters of spring blooming natives: Phlox divaricata ‘Blue Moon’ and ‘May Breeze’, Tiarella wherryi, Chrysogonum virginianum, all creating groundcover along with groupings of the fern Adiantum pedatum for continuity, and Aster divaricata ‘Eastern Star’ for prolific fall bloom.

From L to R: Tiarella wherryi (foamflower), Adiantum pedatum (maidenhair fern), Phlox divaricata ‘Blue Moon’, Aster divaricata ‘Eastern Star’ (woodland aster).

I’ve also scattered in Uvularia grandiflora, Porteranthus trifoliatus, a few stately Thalictrum rochebruneanum, and all kinds of bulbs from species tulips, Allium ‘Mount Everest’, Camassia leichtlinii, Leucojum aestivum ‘Gravetye Giant’ and Nectaroscordum siculum. It’s my spin on a deciduous native woodland heightened and abstracted, without a hosta in sight.

Meadow matrix melodies

My damp meadow grass matrix (#1) winds through the more open centre of the garden in mid-summer.

Its grassy base is the luminous, Deschampsia caespitosa ‘Goldtau’ interplanted with the magenta plumes of Astilbe chinensis ‘Purpurlanze’ for structure. These are supported by spontaneous bursts of Astrantia major ‘Claret’, Lobelia siphilitica, the red thimbles of Sanguisorba officinalis ’Tootsee’ (sourced from Free Spirit Nursery in B.C.) and umbellifer Selinum carvifolium framing the path’s edge. 

I like to weave jewels in and amongst the matrix and the damp conditions have proven ideal for a lush stand of Veratrum nigrum, which took five years to bloom from seed and  flowered this year with scatterings of Digitalis ferruginea, Campanula glomerata ‘Joan Elliott’ and a few mature specimens of dark-leaved Cimicifuga (aka Actaea simplex).

Veratrum nigrum. A rare gem that takes years to flower.

 

A now signature element was here long before any garden: Equisetum arvensis is a native thug of unstoppable force that thrives on disturbance. But it’s been on the planet for 400-million years and I’ve decided to embrace rather than curse it. Horsetail fills the gaps on the groundcover level, unifies the planting, and shimmers like diamonds in the morning dew.  

I’m also accepting of the native asters that fly in from the pond margins (mostly Symphyotrichum ericoides) but I keep a watchful eye on the progress of cattails (Typha latifolia) and Red-Osier Dogwoods (Cornus sericea) that creep in from the edges. I draw the line at our native Solidago canadensis and pull it on sight, which is super aggressive in a garden context. While a valuable pollinator and host plant, it dominates all the meadow areas of our property and indeed, much of the surrounding  countryside.      

The life aquatic

I found over time that the varying gradations of moisture in riparian plantings can be very tricky to read. The oxygenation levels that determine what thrives or drowns can change within the course of a few footsteps.

Much plant literature talks deceptively about moisture-loving perennials that require “moist but well-drained soil” but what is that really? Well, it’s probably either sandy loam with a high water table or the conditions you find alongside fast-moving mountain streams where plants are immersed in water and oxygenated at the same time.

Great news if you live in the Alps.

My third matrix skirts the edge of the pond with perennials adapted to thrive in wet ground, prone to occasional flooding. Here I’ve mixed prolific self-seeders red, white and blue Lobelias (L. cardinalis, L. siphilitica, L. ‘Alba’) intermingled with the wetland Carex bromoides, and drifts of Iris versicolor.

More structural wetland plants include Flipendula rubra ‘Venusta’, Eupatorium ‘Reisenschirm,’ the giant fern Osmunda regalis, Darmera peltatum, Chelone glabra, all happy with wet feet.

 

Wherever one matrix crosses into another, I’ve blended them together to abstract the edges, which creates yet another set of possibilities for the garden to grow into itself.  

I’ve put Piet’s advice into action and continue to make adjustments along the way to modulate the flow of the design. I’m increasingly able to see and perceive how all the various parts of the planting interconnect in ways that would escape the casual visitor.

It’s far more though than just a living experiment in planting design. The pond garden now creates its own charged atmosphere and emotionality, attracting an astonishing diversity of life to what was previously neglected space.

Next year, it will be open from time to time for all curious and like-minded souls visitors to experience for themselves.

The lower pond garden captured in July 2021. Each year presents a fresh chapter in the evolution of the original design.

Note: This story was originally published in the 2020 edition of The Prairie Garden from Manitoba in Western Canada.  It was also translated into both Japanese and German and published in the March 2020 issue of Gartenpraxis, Germany’s leading horticultural magazine.  

26 thoughts on “Supernaturalistic: The New Perennial Pond Garden

  1. Great article as ever. The “moist but well drained” monicker that seems to accompany every perennial in every plant book that I have read drives me mad, especially when coupled with happy in clay soil? Seems a bit contradictory to me.

    I have found that in our Clay loam topsoil overlaying clay, which can have a perched water table above the clay, perennials survive as we are on a slope and the water is constantly flowing downhill keeping the oxygen content high.

    Loving the list of plants some l am familiar with others not so. Trying to expand my planting pallet but struggling to find suppliers over here in the UK so may have to start sowing the more exotics.

  2. Thanks for the great text and even better photos!
    Great information for us who are in love with our gardens.
    Thank you for loving nature!

  3. I really enjoyed reading your text.

    It was very interesting and made me reflect on my own approach to gardening.

    However, I was surprised to read that you have decided to embrace the horsetail, as I always thought it would choke anything less vigorous. I guess it is not that agressive then, right?

    Anyway, thanks again for sharing your process. It will certainly keep some of your points in mind when I start planning my next gardening projects.

    1. It’s definitely aggressive and comes up in between and through everything else but they all seem to co-exist. If it overwhelms a lower-growing plant or area, I pull it back by hand to edit. But it works nicely with emergents rising up through it, like a good matrix plant.

  4. Really good, comprehensive analysis of your design process to date, Tony. I will be looking at your open dates! (Or maybe I’ll just make my own….) Thank you.

  5. I thoroughly enjoy your writing and beautifully illustrative photographs. Great inspiration. Thank you.

  6. Wonderful transformation of your article, Tony! I loved seeing all the additional photos and learning more about your plants and design process. Thanks so much for adding the link to our publication at the end. We were proud to have both you and Janet as contributors in the 2020 edition.

    1. You’re very welcome on all counts. It was a great idea to bring the story of its making up to date and really dive into the details. Thanks again for putting it into print.

  7. Your garden is a masterpiece and this post a wonderful overview of your process. Very inspiring. Also looking forward to the open dates.

  8. A wonderful post. I have been slow to respond because I have been reading, re reading and digesting. I envy you your connection with Piet Oudolf but I am happy to connect with the ‘fast learner’. I think we may have unwittingly applied some of your philosophy when we planted what we affectionately call, The Swamp. So glad to read that it doesn’t just have to be a sun baked meadow. We also got it right with plant sociability and succession in The Swamp. So happy that a friend suggested your blog. Thanks again.

  9. Hi,
    Climate in Nothern Russia is hot in summer. No wet soils, sun is running until 10pm.
    Where can I place the perennials for the pond? In the shade?
    With best wishes, Olga

    1. It sounds like you have a kind of rain garden habitat? Where the soil can shift from wet conditions earlier in the season to dry later in the summer? If that’s correct, then look for plants and grasses suited to your habitat that can thrive in rain garden conditions and extremes of wet and dry.

  10. Wow, very impressive. I like your ideas about complex matrices and incorporating degrees of plant “sociability” in the planting design. The plant palette is also very intriguing, and they seem to knit together beautifully. So eager to see how this garden continues to evolve!

  11. Great post Tony! I love what you’re doing over there. It looks amazing. Regards the Horsetail, i’m reminded of Henk Gerritsen when he said you should ‘garden like a grazing cow’ and simply rip the tops off plants you don’t want. Denying them their life source, will often keep them under control. Love your posts… keep it up. Maybe have a little read of my latest post. Again, it’s on a New Perennial theme…. and the dreaded ‘B’ word – Brexit. 31st Jan… a sad day for many millions over here! http://marcsgardens.blogspot.com

    XX

  12. I think what I appreciate most about this style of planting is that it is so intuitive. A person who knows nothing about plants would still look at it and feel like it looks “right.” Yet, the same person may look at another planting and not have the same instinctual response. because the arrangement of the plants is unnatural or the plan combines plants of drastically varying ecologies. I have always been of the mind that we should be working with what we have available to us, and not stress over the things we can’t change (especially important these days!). On that note, good job recognizing the attributes of horsetail and working them into the plan. Gardens should bring people joy, including the gardeners. Every time I am doing a maintenance task that I just hate, I’m always scheming how I can eliminate that task, and it usually involves pushing some traditional boundaries. This just feels like steps in the right direction.

    1. Great insights, Andrew. Yes, less can be more when it comes to maintenance. Spring is my time to really take care of tasks before the garden comes back to life, at that point I’m far more laissez faire and just really editing minor details and yes, admiring the horsetail;-)

  13. Great work Tony. Awesome results. I very much appreciate the design concept and the way you carried it maturity. Could you comment on the management of the planting…or is it just left to develop as it will?

    1. Hi Jim,
      I actually do a bit of both. I view maintenance more in terms of managing the garden space as a whole than on a plant by plant basis (with exceptions). I use no fertilizers or pesticides, with only targeted use of herbicides.

      I perform all maintenance myself for 6-8 hours each week in the more active parts of the season; most tasks occur in the spring starting with the cut-back and weeding and continue to weed outliers through the growing season and discreetly stake taller plants.

      For sure, management is a critical continuation of the design process. It provides an opportunity to take the pulse of the garden and critically evaluate how all parts relate to the whole. In the spring and fall, I tweak the plantings at my discretion by either moving plants, dividing older clumps, or replacing plants that are not performing up to expectations. During the summer, I pretty much leave the garden to do its own thing and this garden is wilder than most – better to accept that and work with it.

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