About the SFMGA

Sunday, May 31, 2009

Efficient water use is effective water use

By Dr. Curtis Smith, NMSU Extension Horticulture Specialist

Efficient use of water means more than reducing water use. It means the water must accomplish the purpose intended, the proper growth of plants. Water used to grow plants, but not used effectively is wasted because the plants do not grow as intended.

Landscape irrigation has several purposes, but ultimately the purpose is to sustain an attractive landscape while using the water efficiently.

One landscape use of water is to establish plants. At this time the plants are usually small and require less water than when they are large, but water must be provided frequently. After plants are established water is used to foster optimal growth. Maintaining optimal growth requires more water than that necessary to just keep the plants alive. However, during times of drought water is used only to keep the plants alive until the drought has ended. The plants may not be as attractive during a period of irrigation for survival, but if kept alive, the plants can return to an attractive state when the drought has ended. Water that does not accomplish the intended purpose is not used efficiently.

How to Water Houseplants Correctly

The concept of effective and efficient water use is relevant for growing houseplants also. Water is often wasted in watering houseplants because gardeners don't understand the unusual characteristics of common potting soils. These soils will resist wetting when allowed to dry. Effective water use requires the gardener to understand how to remoisten the soil. Potting soils also accumulate salts that ultimately damage plant roots if the water is not properly used. These two characteristics can create a challenge for gardeners, but there is an easy and effective solution.

When potting soils have dried, they often shrink away from the sides of the container in which the plant is growing and drains from the hole in the bottom of the pot rather than wetting the soil. However, pots without holes are not the answer to the problem, drainage holes are necessary. Some gardeners moisten the soil slowly by making several applications of water and gradually remoistening the potting soil, causing it to swell and close the channels that allow the water to run around the soil rather than moisten the soil. Another method is to place the pots in a dishpan or other basin and slowly add water and allow it to slowly soak in through the drainage holes. If the water level is raised too quickly, the pots will float and turn over. Once the soil is thoroughly moistened, the pot can be removed and surplus water allowed to drain and carry away salts that would otherwise accumulate and cause problems.