Peter Del Tredici’s Wild Urban Plants of the Northeast serves not only as an absorbing field guide to spontaneous urban plants but also as a razor-sharp critique of how we value urban plants in general. In clear, jargon-free language, Del Tredici lays out his challenge to our ecological assumptions in the book’s introduction. He describes how we have a tendency to negatively judge plants that grow without human intention. Indeed, most of the plants described in this book are traditionally dismissed as weeds. Furthermore, we negatively judge plants based on their place of origin, labeling non-native species as “invasive.” Del Tredici argues that by automatically tagging these spontaneous urban plants as ecologically harmful, we ignore their potential benefits.
The entire concept of native and non-native becomes complicated when we consider the reality of urban conditions. Del Tredici challenges the notion that native plants can always be restored in urban landscapes, writing “(1) most urban land has been totally transformed from what it once was; (2) the climate conditions that the original flora was adapted to no longer exist; and (3) most urban habitats are strictly human creations with no natural analogs and no indigenous flora.” Cities represent entirely new conditions that native species are not necessarily adapted to. For this reason, native plants often require extensive human management to survive. Accordingly, Del Tredici dismisses the concept of urban ecological restoration as “really just gardening dressed up to look like ecology.” Instead, the plants that thrive in cities are already evolutionarily adapted for harsh conditions. Because they grow in cities without human input, they are, in a sense, the natural urban flora. These species can deliver significant benefits to urban ecosystems and should not be disregarded. For example, these species reduce the urban heat island effect, protect against erosion, stabilize stream banks, manage stormwater, create wildlife habitat, produce oxygen, and store carbon.
By challenging the way we value urban plans, the book forces us to reconsider how we design our urban landscapes. For this reason, the book is of particular relevance to landscape architects, though it is not specifically written for them. Discussions of sustainability frequently involve the use of native species, but how sustainable is a landscape that requires frequent maintenance? After all, plants that grow and flourish without human intervention are, by definition, sustainable.
Del Tredici touches on some landscape strategies that utilize spontaneous vegetation. These strategies involve the employment of selective editing – the targeted removal of certain undesirable species – to guide spontaneous plant growth to a desired result. He brings up the possibility of the spontaneously generated green roofs, high-performance urban meadows, and ecologically beneficial lawn alternatives. The design implications for spontaneous vegetation are vast and far beyond the scope of this book. For instance, spontaneous vegetation could be a tool for inexpensively transforming vacant urban areas into ecologically and socially beneficial spaces. Old industrial cities such as Detroit and Buffalo already grapple with the phenomenon of the “urban prairie.” Can these maligned spaces be turned into assets? Of course, any strategy utilizing spontaneous vegetation would need to fully address issues of safety, health and aesthetics. In New Orleans’s Lower Ninth Ward, a post-Katrina proliferation of spontaneous vegetation is generally seen as a threat to the neighborhood’s viability. Is there a way we can selectively edit this vegetation to benefit, instead of threaten, the neighborhood?
Del Tredici follows his eloquent 30-page introduction with the bulk of the book: a 300-page field guide to spontaneous urban plants. Each species gets a full page of text and a full page of images; by giving these plants visibility, he makes them impossible to ignore. Significantly, in addition to basic identification and habitat preference, each plant is described in terms of its positive ecological and cultural significance. These descriptions make the field guide an entertaining read and elevate it far beyond a simple tool for plant identification. Del Tredici deliberately omits any negative ecological qualities that these plants may have; the book aims to challenge our perceptions of these plants, not necessarily provide a balanced perspective.
By refusing to address any negative ecological consequences of these species, the book does lose some of its utility to landscape designers. While hinting at the potential of spontaneous urban species in landscape design, it does not work as a guide to their use. Similarly, while the book does bring up the strategy of selectively editing plant species, it does not describe how to kill them. While this information is useful and necessary, it is beyond the scope of the book. Written for a general audience, Wild Urban Plants of the Northeast is not intended as a guide to designing with spontaneous vegetation. Instead, it serves both as an eye-opening guide to plants often overlooked, and as a challenge to our notions of nature and the way we determine the value of plants.
In a culture where any alternative to the lawn can be controversial, we need to change the perception of wild greenery before we can design with it. Del Tredici strives “to teach people how to identify the plants that are growing in urban areas, and to counter the widespread perception that these plants are ecologically harmful or useless and should be eliminated.” In this aim, he resoundingly succeeds.
This guest post is by Benjamin Wellington, Student ASLA, master’s of landscape architecture candidate, Louisiana State University, and ASLA 2012 summer intern.
Image credit: Comstock Pub Assoc