Garland Nursery Newsletter July/August 2010

By Joleen Schilling

Water makes up 90-95 percent of the plants we grow. It is essential for the survival of all the plants in our gardens. Plants need water for photosynthesis, to help them absorb minerals in the soil and transport nutrients throughout the plant. During the heat of summer, plants are cooled by water that is evaporated through the leaves. Plants also store water in their roots for use during cold winter months. Water is also responsible for keeping plants upright.

Because of the vital role water plays in the survivability of our plants, knowing how to water is one of the most important aspects of a healthy, productive garden.

The amount of water that your garden needs depends on the soil in your garden, weather, the plants being grown, and the age of the plants. Unless plants are extremely dry, the general goal of watering is to replenish the available water in the top foot or so of the soil.

In general, newly established plants require frequent watering while they are establishing a healthy root system. Mature trees and shrubs usually do okay with less frequent irrigation, but it is still important to watch them for signs of water stress.

Many gardeners are unsure about how often to water their plants. As a general rule of thumb, it is best to avoid frequent, light watering as it encourages, shallow rooting and makes plants more susceptible to drought. It is best to apply water at a slow rate (generally no more than ½ inch per hour) over a longer period of time.

The time of day when you water is also important. The best time to water is early morning. Avoid watering during the hottest part of the day to reduce the amount of water lost to evaporation. Watering in the evening is usually not recommended because it favors disease.

When applying water it is important to consider how you can maximize water infiltration and minimize runoff and losses due to evaporation. Consider using soaker hoses or drip irrigation because they both reduce runoff and evaporation losses by applying water directly to the root zone at a slow rate.

Lastly, you can increase the infiltration rate of your soil by adding a 2- to 3-inch layer of mulch to your garden. The mulch will also act like a sponge, quickly absorbing and holding the water.

Remember, there is more to watering than just turning on the hose. If you have questions about watering you can always contact your local nursery professionals or the extension agency in your local area. Happy watering!