This article first appeared in the Austin American Statesman in 1996 but is still relevant today.
by Dick Peterson
You bought a home–it cost a lot of money. Now you want a landscape that will enhance your home’s beauty, add value to your home, and be easy to maintain. Landscaping choices are an important part of the City’s Green Builder Program. By making good choices when you plant, you can save time, money and protect Austin’s beautiful natural environment.
Austin is unique; that’s why you live here, or got here just as fast as you could. But so are Austin’s soils–and not knowing your soil and the plants that will grow and thrive on your lot could be costly both in time and money. The Central Texas region consists of several soil and climate combinations which means that landscape decisions should be specific to your site.
Three distinct vegetation areas meet in Austin: the Edwards Plateau, the Blackland Prairie, and the Post Oak Savannah. Each of these areas has different soil types with different planting requirements. The native and adaptive plants (adaptive plants are non-native plants that thrive in this climate) that will thrive on these soils are also very different. Before you plant, take this tour of Austin soils types and choose your landscape to fit.
The Edwards Plateau is generally west of Mopac. This area features shallow soils with rolling hills and steep slopes. West Lake Hills, Oak Hill, and Rollingwood are representative communities. Commonly referred to as the beginning of the Texas Hill Country, the Plateau’s undeveloped areas are dominated by mesquites, oaks, and cedars (really junipers). When you choose a homesite in the Hill Country, take stock of the existing vegetation and develop a plan with your builder to protect it during construction. Avoid indiscriminate clearing of the land in this very ecologically-sensitive area. Limit fill only to that required to insure adequate drainage away from the foundation. Avoid cheap “sandy loam” fill. It is usually an infertile product referred to by landscapers as “red death.” Use a “landscapers mix” instead.
The majority of new plants in the landscape should be native or adaptive to the area. For trees, select Bur and Chinquapin oaks, cedar elm, Chinese pistache, Mexican buckeye, Mexican plum, Texas persimmon and Texas redbud. For shrubs, select Burford, Chinese, or yaupon holly, nandina, mountain laurel, yuccas, and native bunch grasses.
The Blackland Prairie is generally east of the Balcones Fault. Soils in this area are mainly deep and the terrain is gently sloping. Sunset Valley and Manchaca are right on the dividing line. The intersection of the Missouri Pacific and Southern Pacific rails at McNeil is just west of the line. Undeveloped homesites in this area were once farmland. Fertile areas near Del Valle and Govalle were used as truck gardens at the turn of the century and provided early Austinites with fresh produce. Existing vegetation may include grasses and scrub brush. Existing trees may consist of oaks, pecans, and some cedars. Pecans, oaks, and Texas ash are excellent selections for new landscapes. Some shrub choices include cherry laurel, Indian hawthorn, oleander, and Burford, Chinese, or yaupon holly.
The Post Oak Savannah is generally east of Austin. Indicators for this area are sandy, slightly acidic soil with post oaks. Some references include this area in the Blackland Prairie or in a more inclusive area referred to as the Cross Plains and Timbers, so plants from Blackland lists may be appropriate for your specific site. Some landscape plans for this area may include some of the selections from both the Blackland Prairie and the Edwards Plateau lists. This may seem a bit confusing, but look at your actual site. A city by city list of regions is included in the “must have” book, Native Texas Plants – Landscaping Region by Region, by Sally and Andy Wasowski (Gulf Publishing Company). Sally suggests starting “with the city you live in or live closest to. Next read about the possible choices for your area. Then go outside, look at your soil, and match it as best you can to one of those described for your area. The plants listed under your soil description are the ones most characteristic of that region and can serve as indicators.”
Each homesite should be evaluated for the dominant soil type, not by its location on a map. The above regions and soil types are general. Your site may be slightly different from your neighbor, both in soil and climate. If you are unsure about the type of soil, consider getting a soil analysis. This is a free service at some area nurseries, or contact your county Agricultural Extension Service.
Create zones in your landscape according to existing or improved soils. Group plants that have similar soil and water needs together. Keep high water use plants to a minimum and group these together to make a miniature oasis. These small distinct areas can be easily maintained if they are near the front or back door. Be aware of microclimates that exist even on your own property. New Braunfels author Scott Ogden writes in Gardening Success with Difficult Soils (Taylor Publishing), “Even the smallest gardens offer a series of microclimates around the house or grounds that favor various plants and enable a wider variety to be grown.” For example, reflected heat from walls or patios can create pockets of warmer temperatures for more tender plants, while plants exposed to cold north winds need to tolerate colder winter temperatures.
Native and adaptive plants thrive the best and are low maintenance. Low maintenance alternatives to traditional landscaping are becoming the norm. In Central Texas, with our hot, dry summers, native and adaptive plants require very little water to thrive. In the 1980’s, the word Xeriscape was coined from the Greek word “xeros” for dry. Xeriscape is defined as “quality landscaping that conserves water and protects the environment.” It is not a style of gardening, but a method of gardening.
Recently, a neighbor of an award-winning Xeriscape commented, “I’ve never seen a ‘zeroscape’ that I liked.” What he didn’t realize was that almost any landscape he found to his liking could be a Xeriscape. His neighbor simply preferred a more natural style. A very formal landscape, or even an oriental garden, could be a Xeriscape.
Xeriscapes depend on seven basic principles. By using these principles, you can reduce yard maintenance, use less chemicals and synthetic fertilizer, and spend more time enjoying your yard.
Planning and Design. Developing a plan is the first and most important step in a successful Xeriscape. Consider the regional and microclimatic conditions of the site; existing vegetation and topographical conditions; how you intend to use your landscape; and the zoning or grouping of plants by their water needs.
Soil Analysis. Soils will vary from site to site and even within a given site. Be aware of the acid/alkaline state of your soil and what nutrients are lacking.
Appropriate Plant Selection. Your design will determine the overall effect of the landscape. The actual selection of plants should come from those species that are native or adaptive to your site. Deviation from the appropriate selections creates the need for more soil amendments, more maintenance, and different watering schedules. Think low maintenance.
Practical Turf Areas. Lawn grass usually covers more of the landscape than is needed for entertaining or recreation. For a more interesting and manageable yard, use turf as a fill-in plant. Increase the area of decks, porous paving, paths, and mulched planting beds to reduce turf. Be sure to select drought-tolerant grass varieties such as Buffalograss and Bermudagrass in the sunny lawn areas.
Efficient Irrigation. Water infrequently, but when you do, water deeply. Plants and grasses develop deeper, drought-tolerant roots when forced to find deeper moisture. Frequent, light watering results in shallow roots, leading to water stress during periods of drought.
Use of Mulches. A 3″-4″ layer of organic material should cover all exposed soil areas. Replenish it twice a year. Mulch retains moisture, controls soil temperature, discourages weeds, and prevents erosion.
Appropriate Maintenance. You can’t totally eliminate maintenance, but by following the first six principles, you can reduce time spent on maintaining your yard. After they are established, Xeriscapes require less fertilizer, chemicals, and less water. Your neighbors will admire your landscape and may not even realize it’s a Xeriscape!
You can have a beautiful, efficient landscape that is friendly to the environment. Logical landscape choices will insure our children will have a cleaner, greener planet. The future depends on you. For more information about Xeriscape, call the Austin Xeriscape Garden Club at 370-9505, or see the Xeriscape page on Sustainable Sources.
