Landscape Guide: Irrigation Practices

Introduction | Water Characteristics | Soil Management |
Irrigation | Turf Grass | Water Features | Plant List

Effective Irrigation

Irrigation systems vary greatly in detail, depending on the landscape design and particular plants, but the principles are simple and widely similar. Among some of the principles to keep in mind are these:

• In seeking a low point, water may cause ponding or runoff onto adjacent property.
• Regular and moderate watering is more effective than infrequent flooding or light spraying.
• Irrigation can lead to salt buildup, unless steps are taken to minimize it.

Designed properly and used wisely, an automatic irrigation system can go a long way toward producing healthy, good-looking plants. Conversely, a poorly designed and inappropriately used irrigation system can result in unhealthy plants and a lot of wasted water.

Before converting to recycled water use, you should evaluate your existing irrigation system for:

• available water pressure throughout the system, as sprinkler heads perform most effectively within their designed pressure range;
• poor coverage or a lack of uniformity in water distribution as a result of poor design, installation or maintenance;
• problems with over spray and runoff; broken or damaged sprinkler heads;
• operational problems, such as controllers with too few stations or inflexible run times; or controllers that lack the ability to set multiple run times, test the program, or turn the system off during rainy periods;
• hydro-zoning or planting so that plants with similar soil and water needs are located in areas served by the same valve or valves.

Remember that over-watering, under-watering and excess salt levels may all cause the same or similar plant damage symptoms. Check the overall appearance of your plants while using potable water. In many cases, plant decline can be traced to excess water in combination with poor drainage, rather than the quality of your irrigation water.

Plants vary widely in their ability to tolerate overwatering, but overwatering of landscapes remains common place, particularly for established plantings and turf. When using recycled water, anticipate a period of transition from overwatering to the optimum amount necessary to meet plant requirements.

Overhead (Sprinkler) Irrigation vs. Soil Applied (Low Volume) Irrigation

The method in which irrigation is applied greatly affects plant growth and appearance. While most landscape plants show little to no aesthetic damage due to recycled water, a few plants are sensitive to recycled water when applied with overhead irrigation. Leaves of some sensitive plants tend to burn. This occurs when there is direct absorption of sodium and chloride into leaves and is most likely to occur during hot, dry weather.

Smart Watering

Some of the benefits of good water management include:

• more effective use of dollars spent on irrigation water
• improved landscape appearance with fewer wet or dry spots
• reduction of runoff to streets and over sidewalks
• reduction of water lost below the active root zone
• reduced fertilizer and other chemical requirements

Irrigation System Performance

Whether watering with overhead sprinklers or a low-volume system, keep in mind the following simple rules:
Water early in the morning when temperatures and winds are low and humidity is high.

Avoid watering during the heat of the day, when a tremendous amount of water will evaporate quickly, often leaving a white residue on the foliage.

During the summer, occasionally water 10 to 15 percent more than is usually required. The extra water carries the dissolved salts safely below the active root zone and prevents harmful salt accumulations.

Smart Watering Tips

Use best management practices (listed above). Evaluate the optimal irrigation method for your landscape.
Leach landscapes occasionally to avoid salt accumulation

| E-Government Policies (PDF) | Statement of Purpose | Privacy and Disclosure | Security | Disclaimer | Contact Us |