by Nathan Nesdoly

Conceived as a Neighbourhood Habitat Seed Garden, this is a new publicly accessible street-side garden on private property separated from the owner’s main yard by a tall privet hedge. The hedge is roughly the age of the house (about 50 years old) and the current owner decided to keep the hedge for the time being and manage it with regular pruning.

The new matrix garden includes a metre wide mulched strip between the hedge and the garden to allow for easy trimming but also to serve as a “mulched pathway” where trimmed hedge pieces can break down more quickly with foot traffic. We planted two-thirds of the garden on June 11, 2023 and the remaining one third on August 13 as a demonstration workshop for the 1000 Island Master Gardeners Year of the Biodiverse Garden weekend.

The garden includes 35 species (29 species of flowering plants and 6 species of grasses). Like other matrix plantings, the garden has three design layers: the matrix layer (ground hugging layer—in this case mostly grasses), the vignette layer (plants of seasonal interest such as blooming plants or plants with interesting seed pods) and the structural layer (larger plants that retain their shape and structure more or less throughout the year). In a typical matrix planting, about 50% of the plants are in the matrix layer; in this garden, because it was conceived as a seed resource with a large number of species, only about 30% of plants were in the matrix layer.

In one of the central blocks of the garden, seasonal interest is provided by blooming Rudbeckia hirta, Monarda punctata and Anaphalis margaritacea. The matrix layer of Erigrostis spectabilis and Bouteloua curtipendula act not only as ground cover, but seasonal interest with their distinct bloom structures.

In an adjacent section of the garden, Asclepias tuberosa contributes vibrant orange colour and developing seed pods to the vignetter layer. To the left, a block of Desmodium canadense contrasts in purple. To the right, the delicate and hemispherical shape of the Erigrostis, and in addition to the fronds of Achilliea millifolium, provide a delicate textural element. To the rear are structural large grasses Elymis canadensis and Andropogon gerardii, and towering Helianthus divaricatus, Woodland Sunflower.

In the south block of the garden, Echinacea purpurea and Ratibida pinnata provide colour, with the large leaves of Rudbeckia laciniata just above the Echinacea providing an interesting ground cover texture.

Planning Process and Strategy

Principles

• Know your plant communities. Do your research (but also appreciate that it will never be enough).
• Use 50% grass species (or carex species for shaded areas).
• Plant at least one plant per square foot (10 per square meter). Aim for dense coverage.
• Choose a slate of plants that will suit the light levels, soil and moisture levels of your site. Embrace the features and limitations of your site.
• Relate your design to people (how the space will be used).
• Use appropriate native species—a minimum of 70%.
• Make it attractive and legible (how easily a garden can be understood or made sense of) by using patterns, orderly frames (borders or edges) and surprises.
• Plan for future management, not maintenance, to avoid future chores such as regular weeding, watering, mulching and fertilising.
• Don’t overly enrich your soil—the plants won’t do as well.

Process

• Select tall plants with permanent or seasonal distinctive shapes, either woody plants or tall forbs or grasses (structural layer). Select plants of seasonal interest (vignette layer). Select grasses, or ground covers (matrix layer).
• Place structural plants in your design so interest is spread throughout the garden or concentrated strategically.
• Place vignette layer so that seasonal interest is dispersed throughout the garden, not concentrated in specific areas. Use blocks of plants (large groups) to replicate natural colonies of plants produced through asexual reproduction, or drifts (scattered groups of varying sizes) to replicate the dispersal of plants growing from seed.
• Use natural areas around you for examples of plant communities that work well together.

Soil preparation

We covered the existing turf grass with tarps (lumber wraps left over from a local business) for 6 weeks. After 6 weeks we turned the sod, removing the sod from the perimeter border to facilitate a thicker mulch layer. Finally, we covered area with 5 cm of mushroom compost.

Future Plans

We’ll use this space to facilitate seasonal workshops including:

• Meet the Plants (species identification)
• Meet the Pollinators
• Seed Gathering 101
• Winter Sowing
• Matrix Design and Management

Plants will be a seed source for future neighbourhood plantings. When plants are large enough to divide, they’ll find a home in the neighbourhood.

Lessons Learned

You don’t need to add fertility for native plants (the composted pre-existing lawn would have been enough). Avoid design blocks with isolated “peninsulas” between mulch pathways—plant communities are harder to establish on these narrow strips.

References

• Browne-Grivas, Erica. The Matrix Planting Approach to Garden Design (Horticulture, February 21, 2023)
• Johnson, Lorraine. 100 Easy-to-Grow Native Plants for Canadian Gardens: Revised Third Edition (Douglas & McIntyre 2013)
• Norris, Kelly D. New Naturalism: Designing and Planting a Resilient, Ecologically Vabrant Home Garden (Quarto Publishing Group 2021)
• Rainer, Thomas and West, Claudia. Planting in a Post-Wild World: Designing Plant Communities for Resilient Landscapes (Timber Press, 2015)
• Tallamy, Douglas W. Nature’s Best Hope: A New Approach to Conservation That Starts in Your Yard (Timber Press 2019)
• Piper, Thomas. Five Seasons: The Gardens of Piet Oudolf (Full length documentary from 2017) or any of many YouTube talks by Oudolf