Hort Q&A: Tips for irrigation

Carla Smith, horticulture educator
Pottawatomie County Extension Service

Do you have any tips for irrigation and watering?

While we have recently received ample amounts of rainfall, eventually it will usually get drier as the summer continues. Adequate soil moisture is essential for good crop growth. A healthy plant is composed of 75-90% water, which is used for the plant's vital functions, including photosynthesis, support (rigidity), and transportation of nutrients and sugars to various parts of the plant.

There are several options for applying water to plants. These include: a watering can, a garden hose with a breaker nozzle or spray attachment for containers, small gardens or individual plants and portable lawn sprinklers, a perforated plastic soaker hose, drip or trickle irrigation, or a semi-automatic drip system for lawns and gardens. Some basic techniques for watering are listed below:

Adjust the flow or rate of water application to about one-half inch per hour to avoid causing run-off. To determine the rate for a sprinkler, place small tin cans at various places within the sprinkler's reach and check the level of water in the cans at 15-minute intervals.

When using the oscillating type of lawn sprinkler, place the sprinkler on a platform higher than the crop to prevent water from being diverted by plant leaves. Try to keep the watering pattern even by frequently moving the sprinkler and overlapping about one half of each pattern.

Do not sprinkle foliage in the evening. Wet foliage overnight may encourage disease. Morning watering is preferred.

Perforated plastic hoses or soaker hoses should be placed with holes down (if there are holes), along one side of the crop row or underneath mulch. Water will slowly soak into the soil.

Frequent, light watering will only encourage shallow rooting, causing plants to suffer more quickly during drought periods, especially if mulches are not used. On the other hand, too much water, especially in poorly drained soils, can be as damaging to plant growth as too little water.

Your lawn can use an inch or more of water per week in hot, dry weather. The lawn should be watered when the soil begins to dry out, but before the grass wilts. Loss of resilience can be observed; footprints will make a long-lasting imprint instead of bouncing right back.

Critical watering periods for vegetables are at flowering and fruit development stages.

Be aware of any big changes in your water bill that may indicate a leak in your irrigation systems.   

Oklahoma State University, as an equal opportunity employer, complies with all applicable federal and state laws regarding non-discrimination and affirmative action.  Oklahoma State University is committed to a policy of equal opportunity for all individuals and does not discriminate based on race, religion, age, sex, color, national origin, marital status, sexual orientation, gender identity/expression, disability, or veteran status with regard to employment, educational programs and activities, and/or admissions. For more information, visit https:///eeo.okstate.edu