CHEYENNE MOUNTAIN ZOO

The idea of a “No Water” Garden appealed to the Zoo’s horticulture staff because it is a radical divergence from the normal messages provided about water conservation. Xeriscaping – now part of the average garden vocabulary – educates people to use more low water use plants in yards and gardens. However, the “No Water” Garden concept provides the opportunity to take water conservation several steps higher and shows it is possible to grow plants that require no supplemental water. And since the Zoo considers itself a conservation resource for the public, it is our responsibility as horticulture experts to generate a list of plants that can survive or even thrive in drought conditions and be attractive in the landscape.

Currently, in Colorado's urban areas, 40 to 60 percent of potable water is used on landscapes, which is entirely unacceptable. Colorado is a high desert that does not have an unlimited supply of water. And yet homeowners plant high to moderate water use plants without thinking about the impact of their decisions. Because people often bring along their aesthetic values when relocating, Colorado suffers from the paradigm that yards should be as lush and green as those found in warmer and moister parts of the country. Through the “No Water” Garden concept, we hope to change attitudes and practices of both professionals and home gardeners about what is possible in the western landscape.

Many people don’t realize the direct toll our landscapes take on the environment. Colorado’s water supply comes from mountain lakes and riparian areas and is replenished by rainfall and melting snow. Without precipitation, those sources are not replenished and habitats are destroyed. Riparian corridors make up only five percent of Colorado ecosystems, yet 95 percent of wildlife is dependent upon them for survival. The Colorado River, a main source, rarely reaches the ocean anymore because Colorado and surrounding states collectively draw down nearly the entire repository of water.

Unless we reverse consumption trends, population increases will only worsen the situation. Colorado Springs alone has grown from a city of 200,000 to nearly 500,000 in approximately 20 years. If these growth trends continue and we persist in using 50 to 80 percent of our potable water on landscapes, that translates to an increase of millions of gallons of water used on landscapes.

Colorado Springs Utilities (CSU), which provides electrical, gas and water services to Colorado Springs and surrounding areas, drafted a plan to regulate demand and reduce consumption. Colorado Springs City Council approved the measures and the city entered into mandatory water restrictions. In 2002, CSU’s goal was to reduce citywide usage by 20 percent. Cheyenne Mountain Zoo leads by example and shared with the community ways to decrease water consumption through additional voluntary efforts. The Zoo developed a Water Conservation Plan that detailed usage by the Animal and Horticulture departments and listed ways we intended to drop consumption. We succeeded. Compared to 2001, in 2002 the Zoo's water usage dropped 59 percent in March, 54 percent in April, 19 percent in May, 12 percent in June, 27 percent in July, 33 percent in August, 42 percent in September and 65 percent in October.

On April 5, 2002, the Horticulture department at the Cheyenne Mountain Zoo planted a “No Water” Garden around four Hawthorn trees in a bed between our two parking lots. Aside from the trees, little grew in the area because of the radiant heat from the surrounding asphalt and the lack of a convenient water source. In years past, we added mulch to the area, but otherwise performed no regular maintenance. The Zoo selected a mix of native and non-native shrubs, perennials and grasses ranging in size from two and one quarter-inch to five-gallon pots. At the time of planting the entire bed was thoroughly watered and then we walked away.

The Cheyenne Mountain Zoo received an AZH Conservation award in 2003. We are still looking for ways to sign and interpret the garden for the public. Because of the garden, the Zoo’s Horticulture department has gained recognition with local gardeners, green industry employees/employers and local educators (through Zoo-sponsored teacher workshops).
Project goals:
1. Develop a water conservation plan, by August 2002, for the Cheyenne Mountain Zoo.  Done
2. Do a water audit, by August 2002, to determine how much of our water is used on the landscape.  Done
3. Speak at the Peak to Prairie conference in 2003.  Done
4. Publish our information and plant list on the web by 2004.  Done
5. Label most of the plants in the Garden by May 2006.
6. Provide these plants at our plant sale starting 2003.  Done
7. Work with local media to get the word out to the public.
8. Install a sign to provide the public with information about the garden.

Included are .pdf file spreadsheet links that provide detailed information about our plant list and success rates; Spring 02 Planting, Fall 02 and Spring 03 Plantings, Fall 03 and Spring 04 Plantings, and Survival Results These spreadsheets indicate the scientific name, common name, native status, quantity and size of the species that were planted. Catnip and Bluemist Spirea have an S in the size column because they resulted from volunteer seedlings. S02 refers to the 58 varieties planted in spring 2002, F02 to the 26 varieties planted in fall 2002, and S03 to the 8 varieties planted in spring 2003. Throughout the summer and into the fall, the garden was monitored to see how the plants performed. Their status in noted in the last columns.

‘Never emerged’ applies to plants that were obtained dormant and never emerged or were eaten by deer within the first few weeks. The two plants classified as ‘Early’ endured until June. Those marked as ‘Mid-summer’ survived the heat and drought through the early months of summer and died in late July or August. The ‘Alive, not thrive’ category was reserved for plants that struggled and were visibly weakened, but are still living. When a plant maintained or improved its size, color and structure it was classified as ‘Thrive.’ In the last column, we noted which plants flowered so seeds that emerge in the future could be better tracked.

The "No Water" Garden has received much publicity since its inception. On May 25, 2002, the Cheyenne Mountain Zoo Annual Plant Sale and "No Water" Garden information was detailed in The Gazette, the Colorado Springs newspaper. A short article titled “No Water” Garden Taking Root appeared in the June issue of The Waterhole, the Zoo’s quarterly membership publication. And television and radio coverage of the Zoo’s water conservation efforts and the "No Water" Garden have run multiple times on local stations. The Zoo also has been provided the opportunity to present the “No Water” Garden at the 2003 and 2004 Peak to Prairie Landscape Symposiums in February.

What were the secrets of our success?
* Plant early or late to allow them to take advantage of natural rainfall and cooler temperatures. This may mean planting earlier or later than is commonly recommended. If you can dig the hole, you can install the plant. It is not uncommon for the Zoo’s horticulture staff to plant between snowfalls in March, April, October and November. When you buy dormant plants, check with your favorite nursery or garden center to make sure they will guarantee plants that don’t emerge from their winter slumber. Just remember that plants shipped in from another state must be “hardened off” or they will be frost damaged.

* Water in the plants thoroughly before and after you put them in the ground. Let the roots soak up as much water as possible. This might mean placing them in a tub of water for several hours before you plant.

* Pick the right plants. Not every species can survive with low moisture levels. Use the lists of plants created from actual “No Water” trial gardens. Species that have small leaves, blue or gray foliage coloration, or root structures specially designed to store water will be more successful.

* Plant at the correct depth – don’t force the roots to struggle because they are too low or too high. If they are high, they will be exposed to the low-humidity air and changing air temperatures. If they are too low, they will not be able to get oxygen (especially in clay soils).

* Make sure you mulch the plants to conserve moisture. Apply at least 2” and not more than 4”.

* Use rocks, walls, or other structures around the plants to shade the roots and trap moisture in the soil. They act much like a nurse plant would. We found that this benefit outweighed our concerns about heat reflecting from the rocks and damaging the plants.

* Watch your plants to see how they respond to short- and long-term water shortages.

* Think about whether or not you should amend the soil. The Cheyenne Mountain Zoo had high survival rates without any soil amendment. Amendments help by increasing availability of nutrient and providing better water retention. But what if your plants don’t need the extra help? Native plants have proven they can survive and thrive without any help from man. If you don’t amend, you will have good soil continuity. Many professionals are questioning the wisdom of amending all soil types – the one exception in Colorado would be clay soils.

In the past two years we have received many comments about the significance of the “No Water” Garden. Perennial Favorites, the City of Aurora, and the El Paso and Gilpin County Cooperative Extension Offices have started similar gardens. We are excited about the conservation implications of this project. Email us with any questions or come visit the Zoo and take a walk around the garden to see the success rates. Some plants really are tough and we don’t give them enough credit.
 
 

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