The Self-Sustaining Garden—The Guide to Matrix Planting, by Peter Thompson
The Self-Sustaining Garden is one of several garden books by Peter Thompson, former head of the Physiology Department at the Royal Botanic Gardens at Kew, and is an update of a book originally published in 1997. I was hooked by the cover statement “The harder gardeners work, the more the problems seem to multiply.” And then by the introduction’s opening lines, where he states “If we let them, plants could do much of the hard work of gardening for us. Unfortunately, the ways we have been taught to garden actually prevent them from doing so.” Working less for a better garden? Sounds good to me!
Thompson is a proponent of matrix planting, which he defines as “an unorthodox way of gardening which allows the plants in our gardens to form self-sustaining communities, similar to those in which wildflowers live naturally.” These matrices are successful, he says because they “shelter and protect the plants within them, while excluding outsiders…they have established a balance with one another that enables each to obtain a share of resources, living space and opportunities to reproduce.”
So what he is promoting is planting and maintaining gardens in imitation of plant communities that occur naturally—such as, here in Sonoma County, those in the oak woodland, mixed evergreen forest, chaparral, northern coastal scrub and redwood forest communities. This means creating mixes of plants which are able to meld with one another in a balance which enables all to survive and flourish, and exclude weeds. These are plants that within their own matrix have similar needs for soil type, water, and exposure. The matrix contains larger plants—trees and shrubs, which make up the skeleton or ‘armature’ of the garden, and constitute the top and sheltering layers. It also includes smaller shrubs, perennials and groundcovers which fill in the gaps, and act to keep weeds and unwanted plants from taking hold. He states “matrix planting is concerned with successive layers of vegetation, one above the other, through which plants form multi-dimensional communities”.
He is also a big proponent of matching plants and communities to the local climate, rainfall and soil conditions. No summer-rainfall thriving Asian, English, or East coast plants for Sonoma County in his view. Clearly, selecting plants more in tune with what nature provides locally must lead to the gardener having to do less work and maintenance to keep those plants happy and healthy. In the author’s view, matching plants to local conditions, and mimicking natural plant communities leads to successful meadows, shade gardens, borders and water features, all with minimal upkeep.
The book commences with general explanation and overview, discusses plant partnerships, garden control, and soil care, and then devolves into a series of case studies with clever names that illustrate the matrix planting concept. To put flesh on the concept, there are also several matrix plant lists for specific types of locales, such as plants for dry meadows, and tussock (bunch) grasses for gardens. And there are lists to illustrate the different levels of the matrix such as sociable shrubs, which have open branch structures, long-lived, clumping perennials--those that expand slowly, but produce dense root systems that exclude weeds, and interweaving, space-filling colonists--plants which establish rapidly and spread out to fill space.
The book is oriented more toward temperate climes, generally colder than here, and is therefore not exactly a Mediterranean-centric, bulls-eye guide for Sonoma County, but is nonetheless very interesting in concept, and at least partially useful for actual local design. Combined with one or two key native plant books, such as Bornstein or Smith, perhaps Gardening the Mediterranean Way by Heidi Gildmeister, and information on the natural plant communities that exist in Sonoma, such as Plant Communities of California by Louis Lacey, one can handily experiment with and execute on the concept.