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Beyond Xeriscape A "Friends of Geoffrey"
Perspective on Landscaping in our Sonoran Desert
Twenty years ago the
“xeriscape” model for landscaping in our Sonoran Desert seemed to offer
great promise. The intervening time has revealed several major
shortcomings to this approach. The typical examples of xeriscape are
often colorful and drought tolerant but they lack the natural integrity
of the evolved landscape. The often bizarre plant associations created
in these landscapes have more to do with human whims than respect for
the natural world. The term “Disney Desert” has been coined to describe
the often unfortunate results. Our concessions to the native flora have
generally amounted to mere tokenism, a saguaro here, a palo verde there.
Have we merely replaced one set of exotic landscape plants for a more
drought tolerant set of non-natives?
And what about drip
systems; have they been overhyped as a panacea for our current and
projected water shortages? Wouldn’t a more passive approach which makes
best use of available rainfall be a better model for sustainable desert
living? It’s true that “water harvesting” is promoted in xeriscape
literature but generally as an afterthought rather than the foundation
of the landscape. Nature knows no drip systems, expanses of sterile
gravel, or armies of landscape maintenance workers. Despite that lack we
often claim to find the untamed desert both beautiful and inspirational.
How can this be?
Perhaps a restoration
approach towards landscaping, one which seeks to recreate natural plant
associations wherever possible, would be a better model. Many desert
landscaping books are riddled with non-native plants and there is no
discussion about creating plant groupings which make ecological as well
as aesthetic sense. We should champion the widespread use of such
Sonoran staples as creosotebush, brittlebush, and bursage wherever
appropriate. Our native Velvet Mesquite, Prosopis velutina, should be
promoted over that confusing mix of South American hybrids. This tree
along with the Blue Palo Verde, Cercidium floridum, and the Desert
Willow, Chilopsis linearis, are logical native trees to use in moister
desert locations. The Foothills Palo Verde, Cercidium microphyllum, and
the Desert Ironwood, Olneya tesota, are better choices for dryer sites.
Our plant use recommendations should ideally be determined on a site
specific basis, with due consideration for elevation and the composition
of nearby native plant communities.
We could also lead a
campaign to suppress aggressive non-natives such as African Sumac,
Mexican Palo Verde, Salt Cedar, and that host of introduced agricultural
weeds. Landscape maintenance personnel could be trained to identify and
selectively remove these exotics, preferably at the seedling stage. Any
“volunteer” native seedlings could be left to fill in between our
plantings. This would certainly be a better use of limited manpower than
the time currently spent on the obsessive overpruning of trees and
shrubs. There are plenty of groups currently promoting the xeriscape
approach to landscaping. What we need is a group willing to take the
next step, to move beyond xeriscape.
Charles LeFevre, Apr 2007. |
