Weekend Gardening: Watering Wisdom

June 18, 2011

theresafriday.jpgDry weather is persisting across much of the South. Below normal rainfall and record-breaking heat is taking a toll on local landscapes. Because of Florida’s sandy soils, drought-sensitive plants may experience water stress after only a few days without rain or irrigation. Because water is a valuable resource, it’s crucial that irrigation be delivered properly to ensure plant health and conserve water.

How often we need to water varies, depending on such factors as temperature, rainfall, humidity, season, plants and light intensity. Proper watering is a function of applying the right amount of water at the appropriate times. It is important to get water to plant roots efficiently and effectively and to keep the moisture in the root zone area.

Irrigation Frequency
Many gardeners tend to water lightly every day during dry weather. Light frequent watering doesn’t get the water deep into the soil. Because roots only grow where there is adequate moisture, this practice results in a shallow root system.

Shallow-rooted plants are unable to tap reserves of water deeper in the soil and are prone to drought stress in even brief dry periods. Eventually, your plants become dependent on you to water them constantly.

Established trees and shrubs typically do not require frequent irrigation. For established plants, apply enough irrigation to wet the soil at least 8 to 12 inches deep rather than light amounts that wet only the surface. Deep watering provides water to a larger portion of the root system. A thorough watering should not be necessary for established landscape plants more often than once a week.

University of Florida guidelines call for watering lawns on an “as needed” basis. Lawns that are in need of water will show specific signs. These signs include the leaf blades folding in half, the grass showing a blue gray tint or your footprints remaining visible long after being made.

How Much To Water
To irrigate thoroughly, enough water should be applied to penetrate about 8 to 10 inches into the soil. Applying ½ to ¾ of an inch of water to medium-textured soils generally will accomplish this.

To figure out how long to leave your sprinkler on to apply the recommended amount of water, first, place several empty cans in the spray pattern of the sprinkler. Turn on the sprinkler and check the time. When about a ½ inch of water has accumulated in most of the cans, check the time again. That’s how long it takes your sprinkler to apply a ½ inch of water – and about how long you should leave it on to thoroughly irrigate an area.

The best check of how thoroughly an area has been watered is to go back about 15 minutes after watering and dig into the soil with a trowel. Find out if the water penetrated deep into the soil. Check several places. This procedure also works to calibrate an installed irrigation system or hose-end sprinklers.

In some situations, such as on slopes and heavy clay soils, the water may need to be added more slowly to reduce runoff. It takes water longer to penetrate heavy clay soils than light sandy soils. Run the sprinkler on for 10 to 15 minutes and off for 15 to 20 minutes until you’ve applied a ½ inch of water.

When to Water
Water early in the morning. Less water is lost to evaporation and wind drift in the morning because of cooler temperatures and less wind.

Final Thought
In the long run, organic matter in landscape beds helps to maintain soil moisture. For best results, mulch all landscape beds twice a year. Pine straw and pine bark are excellent mulches along with hardwood mulch.

For more information, contact Theresa Friday at 850-623-3868 or email tlfriday@ufl.edu. Friday is the Residential Horticulture Extension Agent for Santa Rosa County.

Comments

One Response to “Weekend Gardening: Watering Wisdom”

  1. 429SCJ on June 20th, 2011 9:18 am

    Spray the bonsai!, ferns too!

Written by William Reynolds · Filed Under FEATURE TOP STORY, Features, News