Plants’ water requirements vary enormously. Some plants are happiest in soil that is constantly moist while others need to be dry for a while between waterings. Some need to be dry for a whole season, e.g. live oaks in the summer. Plants with roughly the same water requirements should be grouped together in the garden. An irrigation system should be laid out so that plants with similar water needs are watered together on the same valve. Other factors to consider in irrigation design are: whether a garden area is in the sun or shade, what kind of soil it contains and how well drained the soil is. Regardless of how well conceived an irrigation system is, there will be times when supplemental irrigation is necessary. Most often this will occur in a hot spell, but when the irrigation system has been shut off during rainy weather, some plants protected by roof overhangs can suffer from dryness and need hand watering.

As you can see, many factors must be taken into account when determining how much water to give your plants. A stroll through the garden on a regular basis is very important (and satisfying). Plants are generally pretty forgiving, tolerating a little too much or too little water, but I recommend erring on the side of too little than too much.

Automated Irrigation Systems

Irrigation systems need to be maintained throughout the year. Learn how to do this yourself or contract with your gardener or landscape contractor to review, repair and/or adjust your system semi-annually.

Controller/Clock

Familiarize yourself with your irrigation controller. Read the manual or schedule a session with your landscape contractor to learn how to turn the watering system on and off as well as to program each station for the start time, the watering days and the amount of time for each station to run.

Near your controller, keep a reference diagram illustrating the valve number that controls the watering for each area of the garden so you will know which station to turn on when supplemental water is necessary.

Valves

From the controller turn on each valve and make sure that

• Valves work automatically
• There are no leaks
• There are no broken or clogged heads
• Heads do not need to be moved or raised to provide complete coverage
• Valves shut off completely

Drip System

• Locate and flush filters and end caps
• As plants grow, some may need to have additional emitters added
• Verify that all plants on drip are actually receiving water

General

• Know where to shut off irrigation supply line in event of break or malfunction
• Know where filters and flush valves are located
• Know location of valves in event a repair is needed. Recent shrub and ground cover growth can obscure valve boxes.
• Know location of irrigation wires for possible repairs.