Prior to joining Austin Energy Green Building in 2005, for five years I was the Xeriscape Program Coordinator and supervisor of outdoor conservation programs at Austin Water. During my entire tenure at the City, I joined with like minded professionals to discourage the movement to "desert style" Austin landscapes. This misguided movement followed the "lawn to rocks" concepts of our neighboring states to the west. Large expanses of sand, gravel and rocks may be a useful landscape style in desert environments. Even though central Texas may be getting hotter, it is not a desert environment.
In a desert environment, the nighttime temperatures may reach freezing even in summer. These cold nights can "charge" the hardscape with cool temperature. As the day progresses these cooler rocks and even adobe walls begin to give back the "cool". This temperature difference is referred to as diurnal swing. In Austin, we have just the opposite extremes. We are hot both day and night, so any hardscape is charged with "heat" and not "cool". This is referred to as the urban heat island effect.
In the central city we work to offset this buildup of heat with trees, green spaces, parks and even vegetative roofs. But now, misguided professionals even moved the commercial landscape guidelines toward larger and larger expanses of rocks. These professionals are paid to install landscape fabric covered by rocks. They blow what vegetative debris they can into the street with loud blowers. Instead of these leaves and organic matter being allowed to decay naturally in the landscape, it now goes down the storm sewer into our waterways. What they can not dislodge becomes excellent growing medium for weeds and invasive grasses. Bring out the Roundup! Wait 5 or 6 years and they will be paid AGAIN to remove the rocks, reinstall landscape fabric and then reinstall the rocks. All because these "professionals" did not want the job of spreading mulch twice a year.
Why do they have to keep reinstalling mulch? It is organic, locally produced, abundant and decays. That is, it composts in place building the soil and allowing the exchange of oxygen to the roots of plants and trees. How can that be bad?
Now, according to the video, we are finding a 30% increase in utility bills in landscapes dominated by rocks and gravel. Who would have thought that we can (or would want to) create urban heat islands all around our houses, only to have it give back the stored heat just as we arrive home from work. What do we do? Crank down the AC and make the electric meter spin, just when our utilities are having a hard time producing enough electricity to avoid brown outs! DUH! WHO WOULDA THUNK?
I am available to make presentations on landscaping topics. There is no charge for nearby non-profit organizations. Some of the basic concepts have changed as commercial products have replaced the DIY methods shown.
This July, 2016, segment from Central Texas Gardener is one of the most important explanations I have seen about the misguided movement to cover landscapes with rocks and gravel. It is up to YOU to stop this practice!
Dick Peterson talks Rainwater Harvesting on Central Texas Gardener
Rainwater Harvesting Consultant