One obvious was to save watering your garden is to use drought tolerant and native plant species. If you have an established garden, consider adding some of these plant species in your landscape. Native drought tolerant species as well as plants from Mediterranean climates similar to ours offer a wealth of plant materials for the garden. (I will elaborate on this topic later since it is a large subject area.)
Another helpful tip is the method of watering. When you water, it is important to water the entire root zone of the plant, from small herbaceous plants, to large trees. A slow trickling hose (soaker hose, drip irrigation, microspray heads, etc.) will help apply water to deeper soil levels. It is wise to check watering depth in the soil with a trowel or shovel to actually see how deep the water has gone after the area has been irrigated. This checking is important since any number of factors can cause a dry area beneath the soil surface and you will not know it unless you check with a soil probe.
If your watering has thoroughly wetted the area, then you are in good shape.
Now, I would like to introduce you to a particularly helpful method of watering. That is to water that same area again. What you are going to accomplish is the thorough soaking of the root zone area and perhaps a bit deeper. This method works very well in containers. It actually helps the plant go longer between watering. You need to let the soil partially dry between these deeper waterings. That is very important since plant roots need air in the soil structure to keep the roots healthy. The double watering accomplishes thorough soaking of the root area, and ten adds additional moisture to lower soil levels.
The method to use is this: water the plant thoroughly, then wait a few minutes (perhaps 15 minutes or so). This allows your first watering to soak the root area, then when excess water has drained away, you water the plant again. This will often eliminate any dry pockets of soil and you will see your plants respond by looking better! The first watering wets the soil, the second wets the plant thoroughly and allows a moisture reserve to be located in the soil after the plant has taken up the moisture from the first watering.
When I first tried this method, I was amazed! Even root bound plants looked better and grew better too!
Some of then cutting edge growers practise this watering technique. It is still new in the horticultural industry, but I am sharing this advice with you so you may have better looking and growing plants!
Now remember that if your plant is root bound and wilts soon after watering, WATER the plant! You’ll need to transplant it to a larger container or in the ground.
This same procedure works in the landscape as well. Just try it and see when you will need to water again. This will vary depending on your soil type, cultural practises, weather, and individual plant. Just as for containerized plants, you need to check soil depth to see how water has penetrated the soil and if it has wet the root zone thoroughly. Then allow the ground to dry out slightly between waterings. When dry, water again. You plants will have less feast or famine as far as water is concerned.
Time of day to water is also a factor, as well as weather conditions. Early morning and evening will allow the most water to wet the plant and soil area the most satisfactorily. Watering during the heat of the day, or during a windy period will cause much loss due to evaporation.
Consider altering your landscape to allow for more of the drought tolerant species.
The down side of many native species is that even though they conserve moisture, they go semidormant and do not look as good as well watered species. Here I propose another idea to consider. If you have a drought tolerant landscape, consider having a more lush small area. Perhaps a container area of more thirsty plants or a small planting around a patio, etc. This will give you a greener blooming area which is small, and your main landscape is drought tolerant. Reduction of water thirsty plant areas is another way to conserve water. If you have a large lawn/turf area, consider making it smaller. Lawns are the number one water and maintenance areas in any landscape. They require many man hours of time devoted to the area, not to mention watering, fertilizing, pest control, etc. If you reduce your lawn size or eliminate it, you can redesign the area to more interesting and attractive plantings. There are many ground covers, low mounding plants, and low growing shrubs. These provide a nice attractive accent in any garden, and you don’t even miss the lawn. (you get flowers, foliage and plant form instead of just turf)