No matter how much any individual garden may seem like a separate place, a refuge, or an island, it is in truth part of the larger landscape, and that in turn is made of many layers. The layering of the larger landscape varies over place and time, and is profoundly influenced by the life within it.
Some landscapes have more layers than others, and some layers are more apparent than others. The richness of life in any given landscape is generally linked to the richness and intricacy in its layering.
A bird’s-eye view of typical urban and suburban landscapes reveals that they lack many of the living layers characteristic of broadly functional ecosystems. In addition, many of the layers that are present have been stripped of much of their complexity, and because of this, the biological diversity and ecological functions of these landscapes are greatly diminished.
Since we spend so much of our time in such landscapes, it’s easy to adjust to their simplicity and unconsciously to accept it as the norm. However, if our intent is to create beautiful, livable landscapes that are also highly functional in environmental terms, integrating meaningfully detailed layers has to be a primary design goal.
Many suburban residential landscapes already include a few or many of the literal layers that have made traditional habitats and other long-evolved ecosystems so full of life. Existing layers can be enhanced and missing layers can be appropriately created. The key is to develop a familiarity with the basic functions, inter-relationships and living dynamics of layered landscapes, and then to use horticultural skills to reprise and maintain them. Learning to read and draw lessons from the structure, composition, and processes of functional ecosystems will be increasingly essential to good gardening and the making of broadly functional landscapes for life.
The lack of biological layers is especially evident in many commercial landscapes and in the majority of urban landscapes since so much of their available area is dedicated to buildings and to the extensive paving necessary to accommodate cars and other motorized vehicles. Although there are opportunities to reintroduce layers to such landscapes, the greatest opportunity lies in the suburbs, which are now home to approximately half of the United States’ population.
Despite frequent remnant patches of layered woodlands, grasslands, and wetlands within the broad suburban landscape, they are just that: patches. These isolated fragments are typically surrounded by highly altered expanses with minimal habitat functionality. Their separation and relatively small size is insufficient to sustain the great diversity of wildlife that requires larger, continuous habitat. Reintroducing layers to residential landscapes is the best strategy for restoring biological function on a vast scale, contributing to habitat and to a wide range of ecosystem services that are broadly beneficial, including replenishment of atmospheric oxygen, carbon sequestration, groundwater recharge and filtration, soil conservation, and moderation of weather extremes.
The first chapter of this book examines the patterns and processes in wild, unmanaged systems. Using a woodland as example, the chapter unpacks the components of the literal vertical and horizontal layers in a wild landscape. It also addresses cultural and temporal layers, edges (transitional areas), and wildness (the ability of a natural habitat to perpetuate itself).
Chapter 2 looks at relational biodiversity—the interactions of plants and wildlife in a regional ecosystem. Although we often measure biodiversity in terms of the numbers of different species present in an area, this chapter makes the case that biodiversity encompassing long-evolved interrelationships is more meaningful, more functional, and worthy of conservation and enhancement.
The third chapter answers the question, “What does your garden do for you and for the environment?” Some of the human-oriented functions that might be asked of a home landscape include the following:
- create living spaces suitable for play, meals, entertaining
- add beauty and sensual pleasure including color and fragrance, framing, and order
- offer shelter and refuge, privacy and screening
- yield sustenance through edible plantings
- produce opportunities for storytelling and other artistic expression
- inspire and educate by providing exposure to or immersion in natural phenomena including seasonal cycles, cycles of plant and animal growth and migration
Likewise, a home garden can be designed to serve a variety of environmental functions:
- recharge groundwater
- replenish atmospheric oxygen
- sequester carbon
- furnish shelter/cover for wildlife
- promote a stable food web for wildlife
- support pollinator communities
- provide the right conditions for natural hybridization and the continuing development of biodiversity
Because many gardeners confess to an inability to see the life present in local habitats and in their gardens, chapter 4 provides examples and illustrates strategies for developing one’s visual acuity and capacity to observe and recognize local biological diversity.
Chapter 5 applies the concepts and strategies of wild landscapes to a home garden. Drawing on personal experience, the authors look at the composition, content, functionality, and maintenance of the literal layers described in chapter 1, starting from below ground and moving up. Other themes such as managed wildness and edge dynamics (primarily a function of lateral spatial design) are addressed as appropriate within each layer, as are varying site conditions such as moisture gradients (dry, average, moist, wet), drainage (sharp well-drained to nearly anaerobic and poorly drained), pH (acidic to alkaline), and available light (full sun to dense shade). Authentically related plants and animals are shown in various settings.
Although the concepts and strategies discussed and illustrated in the book are applicable to many parts of the world, the book’s specific examples are drawn from temperate eastern North America. They integrate Rick’s conservation-based planting design and management strategies, with Doug’s vision of the roles residential gardens can play in sustaining local and regional insect and animal biodiversity. A chart at the back of the book lists selected plants and the functions they support by region, giving home gardeners ideas for getting started wherever they live.
In sum, this book addresses both the practical and ecological functions of the home landscape. It is not a how-to book. Rather it aims to provide readers with inspiration and strategies for making and maintaining truly living landscapes—gardens that are full of life and truly vital to both human needs and the needs of local and regional wildlife communities. Such gardens offer homeowners beauty at multiple scales, outdoor rooms for a variety of social functions, turf areas for kids and dogs to run and play, fragrance, and edible plants, while simultaneously meeting various ecological functions and providing cover, shelter, and sustenance for wildlife.