Winter Drought Stress Apparent on S.A. Lawns

San Antonio Express News
Gardening, ETC.
Sunday, February 26, 2006

By David Rodriguez

Normally most of us would not be talking about watering problems in our landscapes until about July or August when the temps are 100 degrees plus. Are we in winter, spring or in a drought? The way the temperatures have been changing in San Antonio, you would have better luck picking the winning lottery numbers. It has been so uniquely ever-changing. Many plants are now leafing out. Regardless of the temperature extremes this winter, one obvious thing can be said. We have not had a significant, cold-damaging winter thus far, but we have had very thirsty landscapes.

Dying Magnolia (Photo: plantanswers.com)

Simply drive around town and exam shrubs and trees. Evergreens are showing drought damage including Yaupon hollies, Burford hollies, Ligustrums and live oaks, just to name a few. Around town, even Southern Magnolias can be seen dying or are already dead. Many of these older and well established plants did not have supplemental irrigation throughout this winter. They are showing enormous and severe amounts of drought stress in the visual symptoms of wilting, dull green leaves, smaller leaves, sparse foliage and blooms, brown branches in hardy shrubs and shriveled wood. The lack of normal rainfall that usually occurs in the fall might have had an impact on these visual symptoms in present landscapes. Hopefully this coming summer, we will not see even more of these lagging drought problems.

The average rainfall for the last 30 years has been approximately 33 inches a year. San Antonio rainfall last year was less than 17 inches. First grade math taught me that 33-17=16. Thus stating, we were 16 inches below normal rainfall last year. And per monthly statistics, we are already 2 ½ inches behind for 2006. That is a lot of rain to be lacking.

When walking outside in your lawn, ask these questions: 1) When was the last time you properly watered? 2) Is the grass brown and crispy due to a lack of supplemental irrigation or rainfall? If your lawn is suffering, most likely it is from lack of moisture. We cannot use the excuse that our lawns are still dormant. Why are some people’s lawns (St Augustine lawns) still pretty and green? Ask them! They have been watering throughout the winter!

How can we prevent drought stress damage, not only now, but everyday throughout the year and maintain beautiful, efficient landscapes? The answer is simple…water. Utilize compost, mulch and water again! And select the best adapted variety of plant for the ideal location.

If you have not received at least one inch of rainfall in your landscape in the last month, you need to water your landscape NOW. This water will be critical for the growth and survival of your established plants. Watering is even more critical prior to a really hard freeze, because freezing is a desiccating process, which pulls water out of the cells. Another point to remember in watering your landscape is to remember the trees and shrubs. Most yards are equipped with sprinkler systems, but in most cases this does not help the shrubs because often the systems are installed only to accommodate the lawn area. YOU NEED TO COMPOST YOUR LAWN at least twice a year. This is an important key in water conservation and reducing your water bill. Aerate your lawn in January with a core aerator and top dress with compost in February and mid-October. Please! Your grass will thank you and so will your pocket book. Apply a minimum of a 1-inch layer of compost (top dressing) by simply feathering it evenly across the lawn. This is the key to reducing water needs and even fertilizer in your lawn. Consider reducing the size of your lawn area by adding colorful beds of water saving plants.

Use a soaker hose on established shrubs with enough pressure to squirt water at least 3 inches high from all openings of that hose. The soaker hose should be inverted in the area between the foundation of the house and the base of the shrubs. Four inches of a good grade landscape mulch (i.e. cedar or hardwood) should be applied on top of the hose and around the shrubs at least once a year. This system should be operated at least four hours a day every two weeks in lieu of an inch of rainfall. Keep away from soaker hoses that sweat, because they normally clog up and are much harder to regulate watering patterns. This watering technique should help to keep your residence foundation from cracking.

In times of very severe drought-stress, it may be necessary to apply additional water by using the same system at the drip line of trees, shrubs and grass-one inch of water per week. Soil holds enough water for two to three weeks, so you need to water at least every three weeks during the growing season unless rain is received. This will allow the water to saturate the soil to at least a foot to 18 inches. So apply water less often, but for longer periods of time, at a slow rate. The most ideal system would be to apply the amount of water that the plant needs every day, but when you attempt to do this, your plants will become totally dependent on you. Should you stop, the plants will die.

For more information on winter watering during a drought visit http://www.plantanswers.com/drought_watering.htm There is a new Landscape Maintenance Guide published by SAWS that is selling at area nurseries for about $8. This is a full color guide that proves that landscape beauty in San Antonio is a reality, twelve months of the year.

Many of our nurseries are already stocked with a beautiful array of spring color. You can plant containerized plants almost any time of the year, even if we do not get any supplemental rain. Remember to select the most adapted species of plant (not necessarily native) to fit in the landscape. Water well for initial establishment. Use liberal amounts of compost at planting time, and top dress your lawn twice a year. Mulch trees and flower beds at least once a year.

Special Note: This article was written last weekend, meaning that we probably received a little taste of rain during this week. This article presents sound drought prevention practices that will not only save water, but also keep our landscapes in livable conditions. This week’s rainfall was only a small drop in the bucket.

Remember, Learn and Have Fun!

David Rodriguez is the County Extension Agent-Horticulture, Bexar County. For more information, call the Bexar County Master Gardeners “Hotline” at (210)467-6575 or visit our County Extension website at https://bexar-tx.tamu.edu

 

 

 

 

 

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