Use edges and value the marginal.
We know that there are different kinds of ecosystems in the world: forests, prairies, deserts, and so on. Logically, this means that there must be places where one kind of ecosystem stops and another begins. These transition areas are sometimes gradual and sometimes abrupt. They are called ecotones, and they are often more biologically rich than the area to either side of them.
In a natural yard, edges are important in several ways. First, even in the smallest yard, there will be edges between different areas – the border between a sunny patch and a shady spot, or the place where a vegetable garden meets a planting of wildflowers. Where space permits, gradual transition zones can be established between different areas. Where this isn’t possible, abrupt transitions can offer interesting opportunities.
One of the most abrupt transitions in a yard is the edge between a planting area and a paved area – a sidewalk, driveway, or patio. While these edges can be tough locations for plants, they can also be very favorable sites. The edge of pavement is typically warmer and drier than nearby areas, as well as sunnier, with less competition. Establish plants that like these conditions, and they will be very successful. Be sure to plan ahead, though, and avoid species that will lean or spread over the pavement.
Finally, suburban yards are defined by edges – that is, by the property lines. These may be areas in which to exercise restraint, in order to keep the peace with neighbors who prefer a different style of gardening. But, there is also a valuable opportunity to collaborate with neighbors in order to garden as though property lines don’t exist. Typically, nothing but the adjoining property owner’s agreement is needed to establish a planting that flows from one yard into the next.
When we start linking natural yards in this way, we can truly begin to restore healthy habitat in our communities.