Going Green
Toxic-Free City Spaces
A quiet revolution has been taking place in our city parks and
public spaces. In 2004, the City of Santa Barbara officially
adopted (although the groundwork had been laid for a number of
years by then) an Integrated Pest Management (IPM) program that
aimed to reduce the use of toxic chemicals in the maintenance of
parks and urban forests. In the past, prophylactic applications of
chemical agents to control disease and pest outbreaks were
performed on a regular schedule with no regard to the actual
presence of pathologic elements. IPM programs typically strive to
employ the least toxic materials for treating pests and diseases in
the landscape, based on evidence gathered during regular monitoring
of the area. Initially this might lead to some drastic changes that
reject the use of poisons to contain undesirable organisms in the
landscape. In other cases, it might lead to finding a substitute
that is less toxic to control a problem. Since this commitment was
made, the use of dangerous pesticides and herbicides has been
reduced by 90 percent in city spaces. City park staff relates that
the amount of the most-frequently used herbicide, Roundup, has
fallen from 35 gallons to under six gallons per year. Other
materials have been totally phased out.
One key to the success of the program has been the further
adoption of a zonal approach to reduce not only the hazards of
toxic chemical use, but the public’s exposure to them. This
Pesticide Hazard and Exposure Reduction (PHAER) system attempts to
identify areas of maximum exposure and eliminate or reduce, as much
as possible, the use of toxic materials there and substitute more
acceptable treatments in each of the zones. Compatible materials to
treat pest and disease outbreaks are listed for each of the zones.
Treatments are limited to those on the list and are only applied
when a problem is identified of a magnitude to justify
intervention. Green zones are totally benign to their human
occupants; yellow zones are areas with greater pest or weed
problems requiring occasional use of materials that would be
excluded from the green zone; and red zones (very few and slated to
be phased out) are identified as those where serious problems still
require somewhat conventional solutions to gain control.
The transition hasn’t been easy and many of the ultimate goals
have not yet been reached. In fact, the City is following a path
that many other institutions have discovered as they pursued these
same targets. It takes time and money, to identify and implement
change. In many cases, it comes down to redesigning landscape
features so that they can be treated differently. These
modifications occur slowly and in stages. The beauty of the PHAER
plan is that there are concrete timelines and transitional states
on the path to success. The City has prioritized its parks, slating
those with the potential for the highest exposure rates, for early
action. The target date for implementation of all the desired
elements of this plan is 2012.
Let’s hope that it is easier and cheaper to implement the plan
than this timeline predicts, but in general, this approach does
require more labor to achieve the same result that chemicals used
to do with just a squirt. Take these examples: Grassy areas
adjacent to a popular swimming pool have over the years become
invaded by clover. No big deal, except that clover attracts bees
and barefooted swimmers were at risk for annoying or, in some cases
life-threatening, bee stings. The selective herbicide that had been
used is now no longer employed. Instead, the turf gets a little
more nitrogen to pump it up and the maintenance crew has set the
lawnmower a little lower to favor the grass instead of the clover,
which doesn’t have the energy to flower if it is cut close to the
ground. Another example: six years ago, park staff applied a ton of
worm castings to an area of Alice Keck Park Memorial Gardens that
was planted with various hibiscus species. The newly rampant giant
whitefly that has recently made its way north from Mexico, find
these plants particularly attractive, but the organically repellant
nature of plants grown with worm castings has kept them at bay all
this time. Additional applications of this magic elixir have
reduced spider mites on other plants at this botanical park as well
as Xylosma trees in Willow Glen Park and hibiscus shrubs at De la
Guerra plaza.
Weeds throughout the purview of the parks department are more
likely to be controlled by mechanical means now. Besides the old
reliable methods of pulling and hoeing, devices such as the
aquacide weeder, which uses super-heated steam, and a
propane-fueled torch, both use heat to shrivel weeds in pathways
and other areas dominated by hardscape elements.
It may not be uncommon for some of us to imagine that our civic
bureaucracy is responsible for the greatest violations and
infringements, in ours and many other regions. In this case it just
isn’t so. The vast majority of pesticide and herbicide purchases,
and therefore applications, are performed by Joe Average.
Homeowners use an estimated 78 million pounds of insecticides,
herbicides, and fungicides per year, 50 percent more today than 20
years ago. Of the 110 children in one major urban area that were
tested, 99 percent were found to have chemical traces of such
products in their blood. Runoff from lawns doused with “weed and
feed” fertilizers is laced with pesticides and fungicides that end
up in our oceans. In our attempt to control insects in the
landscape, we kill an estimated seven million birds a year.
It is just such exposure that the City is striving to reduce. If
the city parks can be beautiful and healthy to visit, why shouldn’t
everyone else who gardens and tends landscapes take heart and learn
from their example? No reason at all. It may take a little time,
but any step in the direction of creating a more natural and
balanced ecosystem will contribute to the overall health of our
urban area. City spaces are becoming a shining example for us to
emulate in this quest.
