Landscape Irrigation

Yes, you could just set garden-hose sprinklers on your lawn and take a watering can out to your flower beds every day, but that's neither energy-efficient nor time-efficient. Fortunately, there are better ways to quench your plants' thrist.

Irrigation systems are available in two main types:

• Stationary sprikler systems
  A system of rigid pipes mounted with fixed sprinklers and sprays.
• Drip irrigation system
  Flexible pipe with holes at regular intervals which release water directly onto the ground.

The choice depends on the type of area to be watered, plants' requirements, and the time you want to spend. Sprinklers work best for lawns, ground covers, and other low-growing plants. Pop up sprinklers, 3 to 6-inch high heads that produce a tight pattern and emit a constant flow of water in a short period of time, are ideal for small lawns. The area of coverage can be adjusted from 5 to 15 feet, the nozzles are adjustable from 90 to 360 degree sprays, and they’re recessed when not in use.

Flood bubblers, which provide a high flow of water that soaks the soil, are used near trees and shrubs and in planters.

Drip systems are excellent choices for plants on hillsides, because there is rarely any run-off because of the low precipitation rate.

Sprinkler systems

The most common sprikler system is the pop up type, which uses underground pipes with heads on risers. The system may sound simple, but actually designing and installing such a system requires careful planning and will generally take more than a few weekends to get done right. A badly designed system can do more harm to your lawn than good. Theses systems require not only water flow, but water pressure, as well. Pressure is critical -- to be efficient sprinklers require high pressure (30 to 80 pounds per square inch), not merely at the water faucet, but at the sprikler head itself.

Drip or trickle systems

A drip irrigation system is not only simple to install, at 90% efficiency, it's also the most efficient type of irrigation available. It can also reduce disease problems that some plants develope due to high levels of moisture. This system applies water directly to the soil through a tube, with the volume of water determined by the size of an emitter on the tube. Emitters range in size from 1/2 gallon per hour to 5 gallons per hour of delivery, with 4 liters (1 gallon) per hour being the most common.

Drip systems work at low pressure (10-30 PSI). There are also spray-mist emitters and other specialty emitters. These systems require a main waterline (from water source to the valves), valves, a submain line (from valves to the connection point of the tubing), drip tubing (polyethylene tubing) a backflow preventer, filter, emitters (these release water to the plant. Small plants need two, trees need three or more) and an end cap. Most systems will require a 20 mm (3/4-inch) valve. Drip tubing is a thin-wall tube and is generally produced in metric sizes. The length of drip hose should not exceed 60 meters (200 inches) from the point the water enters the tube to the end of the tube.

To avoid leaks and damage the system, be sure to choose fittings in precisly the right size and avoid very thin tubing. Total length of the mainline and the sub-main together should exceed 120 meters (400 feet).

Other irrigation ideas

A sprikler system can be fitted with a programable timer to more efficietly control the amount of water plants receive.

To help retain water and cool the soil, try an organic mulch made from bark or cotton by-products.