Since we are now predominately a country of urbanites, the nature that most Americans routinely encounter is in the sprawling shadow of the city, thus it is in this shadow that we must come to terms with our attitudes, perceptions, and concepts of nature. However, the nature that we celebrate is wilderness and pastoral landscapes (Marx, 1964, Nash, 1967, Oehlschlager, 1991, Wilson, 1992). Judged by these landscape standards, urban nature is a degraded, demeaned thing - once a rock dove but now the winged rat of the city. To compensate for this depravation, modern American cities have incorporated islands of nature into urban landscapes through organized systems of gardens, parks, and preserves (Schmitt, 1969, Spirn, 1984, Stilgoe, 1988). These islands of managed nature are sites of formal and mediated encounter where landscape architecture, planning, and environmental professionals provide access to officially sanctioned “pedigreed” nature that incorporates elements of both wild and pastoral landscapes (Hough, 1995).

However, outside these planned and sanctioned landscapes, another kind of urban nature can be found that has received little attention from these scholars. This different sort of nature emerges in unmaintained spaces like neglected creeks, wastewater treatment ponds, vacant lots, road and rail waysides, industrial wastelands, fencerows, cemeteries, dumps, and alleyways. These weedy and unkempt marginal sites in the city are the by-products of urban growth and decay, and they are most often discussed as problems or “trouble spots” to be solved by politicians, urban planners, and environmental professionals (Laurie, 1979, Spirn, 1984, Kendle and Forbes, 1997) and eliminated from the urban landscape. These urban margins can harbor pollution, as well as vermin and disease from illegal dumping. They are also perceived as socially dangerous and squalid since homeless people may use them for campsites and criminals may use them for cover. Thus, at the negative extreme, they are "problem" sites for those city institutions charged with protecting the health and safety of humans and the environment.

But a more positive engagement with these margins occurs as people claim these margins as sites of unsanctioned recreation in the vernacular landscape. Through an informal process of exploration, these margins can become more than just “green space” on a map but rather places of nature encounter and recreation – places where children play and learn about nature, where adults go to birdwatch or to fish or to relax beyond the official confines of outdoor recreation – with the social marginality of these margins somehow a part of their appeal (Dillard, 1987, Pyle, 1993, Nabhan and Trimble, 1994). The strange attractiveness of the margins is both a result of our need for unofficial contact with nature and a result of nature expressing itself in creative ways in marginal places.

Nature can be encountered in these places because of the agency of nature. While urban planning professionals debate what to do with this “idle” land, nature is busy "developing" these neglected sites to its own standards of economy. Native and exotic plants colonize open spaces. Insects, reptiles, amphibians, birds, and mammals readily inhabit these unintended “spontaneous” habitats (Sukopp, 1987, Adams, 1994, Kendle and Forbes, 1997, Wheater 1999). The result is a so-called successional mix of native and exotic organisms. What emerges in these margins is the unintended product of human activity and nature's unflagging expressiveness whose marginality is its defining characteristic both physically and culturally. By traditional landscape standards, these margins are usually not aesthetically pleasing, but they can have their own rough beauty that draws nature writers and others there to seek encounters with “unofficial countryside” (Mabey, 1973) or the “urban wilds” (Pyle, 1993). However, what they encounter is not wilderness or countryside – but a kind of natural place that strains conceptual categories of nature, because marginal nature in the urban landscape is neither pristine nor pastoral, but rather it is a new kind of nature whose ecological and cultural value is an open question.

Marginal nature offers oblique entry into contemporary struggles with the meaning of the nature/culture distinction, for marginal places are access points into the American urban landscape that can illuminate our changing relationship with nature. The neglected margins of the city are unique sounding boards for measuring attitudes toward nature since they provoke ambiguous responses of attraction and repulsion. They are perceptual ecotones where contesting views of nature appreciation and urban land-use come together. Thus, in cultural terms, the marginality of marginal nature is based, not just on its demeaned ecological status, but also on how we perceive these places, how [and if] we use them, and how we value the nature that we encounter there.