House with native plants in front yard
Photo courtesy of Christian Barnard
By Ryan Suttle. Consulting Arborist and Urban Forester.
Conventional urban landscape management strives for a tidy appearance. Grass is mowed to a uniform height, hedges are carefully sculpted, weeds are plucked, and dead branches are removed from trees. While these cultural practices perpetuate the idea of an attractive landscape, birds and other wildlife may be more attracted to neighboring landscapes with a different management philosophy.
Diversity in structural variety, including plant height, texture, and condition, is key to encouraging a proportionate diversity of wildlife use. For example, ground-foraging birds such as dark-eyed juncos may require leaf litter to search for food (Photo 1). American robins feeding on tall grass, or even on bare ground, may need to retreat into understory foliage to avoid predation (Photo 2). Downy woodpeckers forage for insects in dead branches and trunks. To encourage use by a variety of wildlife, a landscape should be highly variable.
A traditionally mowed sod lawn offers little to encourage urban wildlife diversity in this context. Studies have also shown that, all other factors held constant, native vegetation is often better habitat for native wildlife. However, it is impractical and unrealistic for most homeowners to completely replace their established landscaping with an entirely native plant palette. Furthermore, removing established ornamental and exotic landscaping eliminates benefits that they already provide such as ambient or shade cooling, carbon sequestration, habitat for nesting, or habitat for food gathering. How, then, do we meet people where they are and make traditional or exotic species landscaping better for birds and other urban wildlife?
Landowners interested in providing wildlife habitat may learn from the birds and learn to appreciate messier landscapes. Leave lawns un-mowed, let flowers go to seed, leave leaves unraked, and preserve dead branches in trees or entire dead tree snags where they pose low risk to people and property (Photo 3). In more natural areas, downed wood may be placed on the ground in partial shade to encourage use by birds and even reptiles or small mammals. Messy landscaping better meets the needs of urban wildlife than a manicured, traditional landscape – native plant based or otherwise.
Messy is attractive
While native vegetation benefits native urban wildlife, it is often compared to completely mono-structured areas like sod as a reference, completely ignoring differences in garden structure and management. The increased frequency in wildlife use is often attributable to structural variety. Structural variety is achievable with exotic palettes, and achievable with minimal effort where exotics are already planted.
While perhaps not as optimized as natives, exotic plants can still have structural variety for use by a wide diversity of native wildlife. In short, a hands-off management approach encourages structural variety in the landscape through taking advantage of the variety in which the plants in the urban landscape naturally grow. When practical, messy is attractive.