The best time to water is early morning. Avoid evening watering. If evening watering is necessary, try to finish 2 hours before dusk.
To water groups of plants, an oscillating sprinkler and a rain gauge in the area being watered (to measure sprinkler output), is a good way to ensure the proper amount of water is being applied. To water individual plants, place a hose near the stem of the plant, and allow a trickle of water to moisten the area for about 15-20 minutes. In both cases, the use of a timer with a shut-off valve will help prevent over-watering.
1. The need for watering is dependent on the rainfall the plants receive, temperature, and wind. Plants transpire (lose water) more quickly when temps are high (above 80 degrees) and during windy conditions. A general rule of thumb is that plants will do well if they receive 1" of rain (or supplemental water) every 7-10 days. It’s a good idea to place a rain gauge somewhere in your yard to measure rainfall amounts.
2. If we have temperatures above 85 degrees and no rain, watering may be required 3 times per week.
3. Always put your finger in the soil near the root area before watering to check whether the soil is dry or not. If the soil feels moist, there's no need to water.
4. If you water well, i.e. putting down approximately 1/2" per watering, you should not have to water new plantings more than twice a week. If we get rain -- 1/2" or more -- you should definitely water less.
5. Remember that more plants are killed due to over-watering rather than under-watering.
6. Always check the soil with your finger before watering.
7. New plants should be closely monitored for the first two years after planting, and supplemental watering should be provided, if necessary, to ensure good root establishment in the new environment.