Enter the Matrix: New Perennial Planting Stratagems

It feels like forever since I’ve been able to post photos of an actual garden of my own.

I’m thrilled to share spring fresh images from the past few weeks of my new pond garden up at our cabin in Mono, Ontario. It’s zone 4b at elevation, so we’re a month or more behind Europe.

There’s been ceaseless rain in a cool extended spring, helping my young woodland garden find its feet. I’ve been working to complete adjoining areas and getting busy with my Sneeboer Royal Dutch hoe to keep the weeds at bay.

I planted the upper slope matrix featured last last year and added more landscape plugs of Aster divaricata ‘Eastern Star’ to fill in the gaps this spring. There’s tweaking still to do but the overall feeling and flow, the interplay of form, texture and colours, is coming together.

A whole other cast of taller perennials are strategically hidden in and amongst this matrix, timed to emerge later in the season and provide thrills of their own.

Yes, I’m in experimentation mode on a grand scale and having fun doing it.

So, what is The Matrix?

Sorry, Neo. In the words of Morpheus, It’s not about the One, it’s about the many becoming as One. Sort of like how innumerable blades of grass dissolve into the unity of a meadow.

In terms of planting design, the matrix can be described as the underlying base layer of the planting. The greater mass may be comprised of a single species or a combination of perennial species, grasses, sedges or ferns, within which other taller structural plants can emerge. There are advantages to using quieter plants with a long season of interest.

While they can seem similar, a matrix differs from the traditional idea of ‘ground covers’ or ‘underplantings’. Ground covers are quite often monocultures meant to blanket an entire area to the exclusion of all else. A matrix can be far more complex, essentially serving as the ground floor of a designed plant community – growing betwixt and between everything else to help suppress weeds and retain moisture.

The concept is adaptable to almost any given habitat, and highly modular. You can create a micro-matrix or cover a football field with the same basic model.

In my new plantings, I’m experimenting with the concept to create a more dimensional matrix, one which supports the total planting and yet exerts full seasonal interest in and of itself.

For me, this is something of a holy grail. Experienced gardeners look to achieve this in the total garden, while I’m looking to distill it into a single layer. I’m certainly not the first to set out on this path but I’m putting my own particular spin on it.

I’m strategically combining groups of various species together within the same matrix to create an interwoven communal flow across an entire area. Some of the selections bloom in spring (Phlox divaricata ‘Blue Moon’, Tiarella wherryi, Chrysogonum virginianum on the edges), others bloom in fall (Aster divaricata ‘Eastern Star’), while others are more purely textural to add something the whole season long with islands of Adiantum pedatum or Maidenhair fern.

All are North American native woodland perennials but that’s not my defining criteria. It’s as important they share a common habitat – in this case a woodland environment with dappled light and spots of shade with the fertile soil moving from wet to dry as it climbs the slope.

Succession & Sociability

My version is based on what ecologists call succession, defined as ‘the process by which the structure of a biological community evolves over time’.

In a recent Facebook thread, I described this enhanced concept as a complex succession matrix – and I think it fits. The term was inspired by a recent conversation with Frank Kershaw, a venerable teacher of garden design in Toronto.

Of course, it’s closer to what you see in nature itself, with many species strategically intermingled to access moisture and nutrients in any given woodland plant community.

I planted my complex succession matrix in rough percentages for each species, organized into smaller clusters and larger groups. I’m heeding the ecological principle of sociability – based on how plants grow in their native environments, whether in small clusters, large colonies, or solitary specimens.

Woodlanders like the Phlox and Aster tend to colonize in large groups in their native environments, whereas Maidenhair ferns grow together in island drifts.

For the garden, I use deep landscape plugs and small 9 cm pots wherever possible – allowing me to mass in many plants fairly cost-effectively. Some patience is required but the smaller plants will grow in more strongly than large gallon pots.

The various plants will compete amongst themselves to find their own balance and I can edit to fine-tune the overall effect.

I’ve also peppered in other perennials like the occasional Aquilegia canadensis as an accent plant. It’s a heavy self-seeder that grows locally and adds a bold hit of spontaneity as the garden grows in.

In the same spirit, I’ve also introduced scatterings of naturalizing bulbs for spring and early summer starting with species Tulipa clusiana ‘Lady Jane’, Muscari ‘Valerie Finnis’, Camassia leichtlinii, and a variety of Alliums including Nectaroscordum siculum, A. ‘Mount Everest’ and A. karataviense ‘Ivory Queen’. I’m testing to see what works best in the conditions.

The Many are the One

This approach to matrix planting may sound detailed and complex but when you look at it in the flesh, all the parts should seamlessly merge into one glorious whole.

On a practical level, you can create the matrix first and then add in more layers at a later stage. It encourages one to design a whole area vs. working by piecemeal.

The next step is to add layers of taller seasonal accent plants and solitary specimens with the matrix in place to provide a unifying context for the total planting.

As the season progresses, I’ll update to see how the other matrices in the garden are coming along, each designed to perform in the fullness of time.

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Next up:

Stay tuned for the repost of my recent article in Garden Making magazine and The New Perennialist goes West next week to speak and take in the vibes of Victoria B.C.