Drip Irrigation: A Good Choice for Xeriscape Gardens

A description of drip irrigation, it's advantages and disadvantages.

  • Topic: Watering
  • Author: Leon Springer
  • Keywords: watering, drip irrigation , Watering, xeric, xeriscaping, xeriscapes
  • Date: February 2001

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A drip irrigation system can save you water, time, and money, and the benefits are immediate. Drip irrigation, more than any other kind of system, helps young drought-tolerant plantings establish their root system and thrive. A drip system can be buried under soil or mulch and automated with a timer, giving your garden a natural look with carefree convenience. The beauty of a drip system is that it supports plants without being seen. A water filter installed at the beginning of the system will prevent clogging and ensure that each emitter (dripper) will always put out the proper amount of water.

Some advantages of drip irrigation are:

  1. Water Savings Drip irrigation can save up to 50% over conventional irrigation. It can be used on flat terrain or hillsides where wasteful run-off is avoided. Water is applied slowly enough to allow all moisture to soak directly into the soil.
  2. Healthier Plants The slow, regular, and uniform application of water results in healthier growth, increased yields, and consistent quality.
  3. Automation Drip systems can be automated by adding battery timers or electric valves and timers. This keeps soil moisture at optimum levels.
  4. Low Maintenance Drip irrigation covers a small part of the soils surface around the plant, which minimized the most tedious part of gardening—weeding. Fertilizing can also be built into the system.
  5. Low Visibility Drip irrigation tubing can be buried or left above ground. Mulching is often used to conceal the drip system.

Irrigation Basics

There are many parts to a drip irrigation system, and installing one can be a complex procedure. The following information will help you understand what is involved when working with a professional installer.

The key elements that are considered when designing an effective system are:

  1. Flow You can measure the output of your water supply with a one or five gallon bucket and a stop watch. Time how long it takes to fill the bucket and use that number to calculate how much water is available per hour. Gallons per minute x 60=number of gallons per hour. If your system needs more water than the supply will provide at one time, the system can be divided into sections with each section scheduled for a different time.
  2. Pressure (The force pushing the flow) Most products operate best between 20 and 40 pounds of pressure. Normal household pressure is 40-50 pounds.
  3. Quality All drip systems should start with a filter to eliminate clogging by sand, silt, minerals, organic matter, and rust bacteria.
  4. Elevation Variations in elevation can cause a change in water pressure within the system. Pressure changes by one pound for every 2.3 foot change in elevation. Pressure-compensating emitters are designed to work in areas with large changes in elevation or long runs. Inline emitter tubing which is 1/2” tubing with built-in emitters, addresses changes in elevation.
  5. Friction As water moves through tubing, pressure is lost due to friction. In mainline runs of more than 200 feet, there can be a significant drop in pressure that can lower the output of some emitters or sprayers at the end of the line. Pressure-compensating emitters are used in these situations as well as inline emitter tubing.
  6. Timing Watering in a regular scheduled cycle is essential. On clay soil or hillsides, short cycles repeated frequently work best to prevent runoff, erosion and wasted water. In sandy soils, slow watering using low output emitters is recommended. Timers help prevent the too-dry/too-wet cycles that stress plants and retard their growth. They also allow for watering at optimum times such as early morning or late evening.
  7. Watering Needs Plants with different water needs may require their own watering circuits. For example, orchards that get watered weekly need a different circuit than a garden that gets watered daily. Plants that are drought tolerant will need to be watered differently than plants requiring a lot of water. There are many choices of timers available.

Freeze Protection

In most parts of the country, there is a possibility or freezing and/or freeze damage to a drip system. In the fall or early spring there the two areas that need to be attended to are the beginning of the system (timer, valve and filter) and low spots in the system where water may settle.

The following actions are suggested:

  1. Any battery timer should be brought indoors with the batteries removed.
  2. After the main water supply is shut off, all valves should be set on manual open and any canister filter should be drained.
  3. For low spots in the (solid) mainline tubing, either use a flush valve or insert an emitter at the lowest point. As long as the tubing is not full of water there should be no damage.
  4. Another widely used practice is to blow air through the lines with a compressor at the end of the season.

A fertilizer injector is the most efficient way to feed plants. It delivers nutrients directly to the roots of desired plants in a liquid form and is a fast and accurate way to feed an entire garden, landscape or orchard.

Leon Springer is the owner of Dripworks, a fast growing mail-order business with many years of experience giving technical assistance to homeowners, landscapers and farmers all over the United States. Dripworks ships most orders within 24-hours and offers phone support to its customers. Request a free 64-page color catalog by calling 800-616-8321.