Paved with Good Intentions: 5 Reasons Not to ‘Zeroscape’ Your Yard
With the ongoing water crisis, we’re starting to see a lot of formerly lush landscapes suddenly transformed into barren rock-scapes under the guise of water conservation. While these newfound converts to environmentalism are well-intentioned, a rock-only landscape is actually worse for the ecosystem, the climate, and the drought. I know that seems counter-intuitive but here’s why.
A classic scorched-earth, “zero-scape” yard.
First, I’d like to point out that there are more options than just a lush green lawn or a post-apocalyptic dune-scape. There are hundreds of varieties of native and adapted plants that can both reduce water use and provide for a wide range of ecosystem services.
So before you flip your strip, your front lawn, or your entire yard please consider the following.
1. POLLINATOR HABITAT
A butterfly enjoying the Women’s Council Butterfly Healing Garden.
Globally and across the US, pollinator populations are collapsing, threatening our food supply. Whether it’s a sea of Kentucky bluegrass, a field of gravel, or an asphalt driveway – these landscape treatments all lack a habitat for bees and butterflies. A much better alternative would be to provide any number of native, low-water-use plants that provide essential food sources to our pollinator friends.
2. URBAN HEAT ISLAND EFFECT
Diagram from the Urban heat Island Wikipedia page.
Urban heat island effect is a well-documented phenomenon. Large, paved areas that absorb solar radiation result in increased temperatures compared to natural landscapes in the same region.
Therefore, buildings require more energy for cooling, increasing carbon emissions, which then creates more drought.
In comparison, vegetation (especially trees) shade the ground surface and provide evaporative cooling via transpiration. While some rock-scape renovations will at least attempt to keep mature trees in place, irrigation of the trees is neglected, resulting in the ultimate death of the tree from lack of water. Rocking an entire landscape and killing trees only compounds the urban heat island effect.
3. STORMWATER RUNOFF
Photo credit: The Institute for Local Self Reliance
Vegetated surfaces offer many things. For example, their living soils act like a sponge, absorbing stormwater runoff and releasing it slowly back into the water table, holding the water so roots can take it up into living plants. It then transpires back into the atmosphere, cooling and increasing moisture in the air, which eventually turns into more precipitation. Removing vegetation has two effects:
1. While technically permeable, this surface treatment destroys roots and microbes that contribute soil’s ability to hold water.
2. Just the weight of the rocks, including any weed barrier fabrics, compact the soil over time. Anyone who’s removed rock and weed barrier fabric from a landscape can attest to the concrete-like soil they discovered underneath. The result of this is increased runoff.
After a storm, this precious water ends up in the urban stormwater system. Municipalities spend millions of dollars building and maintaining these systems, which are often overwhelmed during major storm events. The impacts of this are flood damage and contamination from water moving across pavement in urban areas.
4. CARBON FOOTPRINT
Image Source: Wikimedia commons, Gravel pit Debiny Osuchowskie.
Let’s talk about where gravel comes from. It has to be mined, usually an open pit somewhere. This causes a lot of dust pollution which settles on our snowpack, causing premature melting, worsening drought issues.
The mining and shipping process for gravel is also very carbon intense. Coupled with the fact that removing vegetation means eliminating a carbon sink, and often releasing carbon stored in the soil and vegetation back into the atmosphere. More carbon in the atmosphere also increases air temperatures.
The cost of cutting back on watering and mowing of your yard is $0. The cost for weed barrier fabric and rock mulch is currently somewhere between $1-$2/sf installed. For an average ¼-acre lot, with an average 3,000 sf front-yard and park strip, the cost to do this type of ‘makeover’ would be somewhere in the $3,000-$6,000 range.
That would buy a lot of plants and composted mulch! The cost for a very basic irrigation system and a native seed mix is about the same if not less.
'ZERO-SCAPE' ISN'T EVEN A REAL TERM
The term “zero-scaping” is just a misinterpretation of the term “xeri-scaping” which comes from xeros, the Greek word for dry. People who generally use the term “zero-scape” are envisioning a rock-filled moonscape devoid of plants.
A properly implemented low-water use landscape, or a xeriscape, reduces or eliminates the need for irrigation with the use of drought-tolerant, native and adapted vegetation. These landscapes require very little water and maintenance while promoting biodiversity, and can be really beautiful if designed well.
The Weiss Residence is a great example of how native xeriscaping can achieve low-maintenance, ecologically-functional curb appeal.
Our firm makes an effort to center all our designs around this philosophy. To see more examples like the Weiss Residence, or to get started with your water-wise landscape today see our Outdoor Design and Ecological Landscapes pages. You can see how we apply wholistic ecological principles across municipal, residential, and commercial projects by visiting our comprehensive portfolio page.