Thomas Rainer, ASLA provided a keynote address to the recent Florida Chapter, ASLA conference that was a synopsis of his recent collaboration on “Planting in a Post-Wild World” (Timber Press). While I have yet to read the book, it appears he is arguing for greater biodiversity in our landscapes. Based upon his relatively brief presentation, I believe his book’s greatest contribution to the practice of planting design is our need to expand our plant palettes to mimic the way plants exist and behave in their natural settings. He goes into some detail about the “social” character of plants and how different species need to occupy varying strata, or layers, of a site or niche.
Hopefully, the book also provides a detailed list of plants that are appropriate for different soil conditions. As a conceptual work it is certainly challenging and inspiring, but just as some exotic planting designs fail because of an absence of plants that accept the specific soil conditions, etc. of a site; one can’t simply go to a meadow and transplant any plant to fit a more natural, layered planting scheme.
If the goal of this new paradigm is to increase biodiversity in the urban environment, there is much more thought to be pursued. One might want to call an environment with humans, roaches, rats and fleas biologically diverse, because there are several species existing in the same environment. When biodiversity was mentioned in the presentation, the focus seemed to be upon “botanical” diversity. If our goal is to create opportunities for true ecological biodiversity within the urban setting, where crickets, frogs, aphids, and butterflies join the rats and roaches; communities must avoid environmental fragmentation and plant communities that support the insects, birds, etc. must be established and maintained.
The attached PDF explores the pros and cons of unnecessary pruning practices and their effects on the integrity of our landscapes. As with many other landscape architects, I often see the character of a designed landscape mutilated by thoughtless maintenance procedures. The attached article may shine some light on the dilemma.
Crape Pruning Etc
I lunched with a group of fellow landscape architects, yesterday. Our discussion turned to the ongoing conflict with locating trees along our streets. This conflict is exacerbated by the desire for safe, easy access and low maintenance of our water, sewer, power, transportation and communications infrastructures. The reorientation of community planning objectives to minimize urban sprawl and to maximize the use of urban spaces through infill, higher densities and more “walkable” neighborhoods adds to the pressure to minimize viable green spaces. Yet, planners are also contemplating the growing data that indicates trees in our neighbors are a benefit both physiologically and psychologically (check out Urban Sprawl and Public Health by Frumkin, Frank & Jackson). At the same time the call for rain gardens and bioswales to minimize stormwater runoff and enhance aquifer recharge has gained acceptance. However, I continue to see inadequate space allowed for trees and bioswales, in most projects and concepts. Until we seriously consider the needs of these natural, green infrastructure elements, I’m afraid we’ll continue to design communities with unnecessary conflicts between the natural and man-made infrastructures.
The use of native plant species is not a new thing. Many of our old standby species are well worn. The ornamental Southern Magnolia (magnolia grandiflora) has been gracing home landscapes since the early European colonists pulled it out of the woods and placed it in a more convenient location near their homes. “Ancient” Live Oaks still line the formal entrance routes to historic plantation sites. But such monocultural plantings were not as kind to the American elm, as it was struck with Dutch elm disease and virtually eliminated as an ornamental landscape plant.
At Ecotone Land Design, Inc. we try to clarify how native plants play a pivotal part in what our cooperative extension service suggest as the “right plant – right place” design rule. Trusting someone who works at maintaining or installing a landscape to give knowledgeable plant selection advise could be risky. If you don’t have time to do your own research, consider finding advice from someone with a horticultural, arboriculture or botanical background to be on the safe side. Knowledgeable people may understand where their shortcomings are and be willing to direct you to someone who can help you with your specific need.
Just because a plant is native does not mean that there is a place for it in your landscape. Your site is likely drastically changed from its “natural” condition, so your soils and water availability need to be evaluated, even though your site was once a wetland. Understanding whether a plant species grows naturally in a “Mesic” or “xeric” environment or in sun or shade are just some of the types of considerations that could make native plants a success in your landscape.
If you haven’t taken the opportunity to review “Visions of Smart Growth and Sustainability”, check it out at flasla.org. I helped to write and edit this 160-page document on regional and community planning.