Watering your lawn
Provide lawns with one inch of water weekly. Whether you have an irrigation system or are watering with a sprinkler, you can easily measure how much water is being applied to your lawn, with these simple directions. Set some empty tuna cans on your lawn where the water will reach them.
1. Turn on the irrigation system or sprinkler and let it run for 15 minutes
2. Collect the tuna cans and pour all of the water into one can
3. Measure the depth of the combined water in the can and divide by the number of cans you used.
This will give you an average since your sprinkler system could be putting out different volumes at different locations in the lawn.
4. Multiply the average amount by 4 to see how much water your system is putting out in an hour.
(You do this last step because you only collected water for one 15 minute segments an hour).
Knowing your lawn needs one inch of water a week, you can now adjust your watering time to fulfill its needs. You may have to split your watering into two applications because it is difficult to apply an inch of water all at one time without losing some to runoff.
Watering your container garden
Water container gardens daily or water the top 2-4 inches of potting soil that appears dry
Watering your vegetable gardening
How much water your garden needs will vary depending on soil type, stage of growth of the plants, amount of rainfall and the temperature, but most vegetable gardens require about 1 to 1 ½ inches of moisture per week during the growing season. Water often enough to keep the moisture level fairly uniform. In medium and heavy soils, an application of about 1 inch of water per week is needed. Follow the directions under the lawn to tell how much your sprinkler or drip system is putting out. For drip irrigation system, simply put the can under the hose so it drips into it.
Adequate moisture is essential to the growth of flowers. Natural rainfall is sufficient at times of the year, but cannot be relied upon as the sole source. Supplemental irrigation is often necessary, particularly during the summer months. Most flowering plants vary in their drought tolerance per week. More may be required during periods of extreme heat. Overhead sprinklers provide the least satisfactory method of watering; they must run for long periods in order to attain deep watering of the soil. Occasional sprinkling that only wets the upper inch of soil is undesirable. Wet foliate may also worsen foliar disease problems and compound problems with control. Drip or trickle irrigation is preferable.
Note: Of course, use a rain gauge so you can adjust how much water it is raining.