Weekly Express-News Article

“San Antonio Life”

By Calvin R. Finch, PhD, SAWS Water Resources Director, and Horticulturist

Saturday, May 31, 2008

“Drought Strategies in the Landscape”

            June is quite often a high rainfall month in San Antonio, but it is also a hot month.  We should plan events, wash our cars, and do whatever else we can to encourage rainfall, but we also need to think about the possibility that the drought will continue.  In fact, it looks likely that Edwards Aquifer levels will fall enough this month that the Edwards Aquifer Authority will declare that area pumpers, including SAWS and Bexar Met will have to reduce pumping from the Aquifer.  Soon after that expect SAWS to escalate their extensive drought management efforts.

            We may as well begin preparing ourselves for a hot, dry summer complete with drought restrictions.  Here are some ways to do that.

            The lawn is the largest water user in a landscape.  To keep a lawn green in hot weather requires watering every week, but usually not more often that that.  Prepare your lawn for once per week watering by shifting to that frequency now.  Apply the water that your soil can absorb and apply it infrequently.  If you fill your whole soil profile with moisture, the roots will grow into the whole area and have access to the whole reservoir.

            If green grass in a drought is not essential to you, and you have zoysia, Bermuda or buffalo grass, you have a second option.  Let the grass go dormant. 

            Mulch is a key drought resisting strategy.  Applying a layer of leaves, bark, pecan shells or other material over the soil reduces evaporation and keeps the soil cool.  Roots in a cool, moist soil are more efficient than those in a baked soil.  When rains arrive and/or you water your plants, the roots are ready to utilize it. 

            Apply two inches of a fine mulch to vegetable and flower gardens where plants are small.  Four inches or more works well over tree and shrub roots.  Mulch is especially important for newly planted trees, shrubs, and perennials.  Place it over the root system. 

            The whole topic of planting during a drought is an issue worthy of consideration.  San Antonio’s climate is a series of dry weather periods alternating with wet weather, if we plant well-adapted plants capable of surviving such a pattern it contributes to a more attractive environment and higher quality of life.  That being said, most of our planting should be done in the fall, winter and spring. Do not be extravagant in planting in the summer, especially a summer in a drought.  New plants require extra water to become established.

            One good drought tactic is to be conservative about excessive plantings during the period, but utilize containers of bougainvillea, moss roses, lantanas, firebush, pentas (shade or sun), and hibiscus for color.  Move them around to create a changing look.  Containers require regular watering, but you receive maximum impact for limited water.