The best irrigation for your garden is the one you can control and maintain. You have four basic options: 1) hand watering with a hose, using either a nozzle or a sprinkler, 2) overhead sprinklers on automatic controllers, 3) low-volume systems and 4) drip systems. Each has advantages and disadvantages.
1. People who hand-water their gardens can adjust the amount of water on a plant-by-plant basis. The time spent watering the garden allows you to examine your plants often and closely. In the dry Southern California climate, overhead watering is not usually a problem for most plants. The biggest problem with this method is that you may lose plants if you are unable to keep up with the watering. Also, if time is limited or you are too impatient to water deeply, your plants may suffer from stunted root systems.
2. Overhead sprinkler systems on automatic controllers free you from having to remember to water your garden. Automatic controllers, though, must be monitored and adjusted to weather conditions and plant needs, and of course, they must be maintained. A power outage causes some controllers to reset to a default schedule of 10 minutes of watering, everyday of the week – a watering regime that is wasteful and unhealthy for most plants. Although it is best to water in the early morning, it is essential to check your system often, so set it for a time that you will regularly see it running.
3. Low-volume systems are easy and inexpensive to construct with plastic tubing and low-volume sprayers. They can be connected to an outside spigot or a sprinkler system, and can be run on a timer. It is possible to design these systems to provide water to small areas, as needed. For example, they can be set up to water new plants during the establishment period without over-watering nearby low-water use plants. Furthermore, they are easy to check since the spray heads are clearly visible. A disadvantage to this system is that the small, plastic parts are somewhat fragile. Squirrels and other animals can gnaw through the tubing or otherwise disturb the system. The controller must be checked and adjusted to meet the needs of your plants.
4. Drip systems are helpful for potted plants, but like the low-volume system, they are fragile - tubing may break and drip heads may clog. Since they are small and often hidden, you may not notice their failure until your plants are suffering from lack of water. Furthermore, drip systems provide water to a limited area and may not distribute it evenly to the plant’s root system.
One of the biggest advantages of using California native plants is that you can select plants whose water needs match our climate. Once your plants are established you may only need to water them occasionally during dry winters and once a month or less during the dry season - late spring through fall – to keep them looking good.