Water Needs of Plants
Plants have widely differing water needs depending on origin and type, among other things. Understanding plant water needs makes it easier to water your landscape efficiently, which in turn leads to lower water bills and reduced maintenance needs.
Plants from arid areas of the world require much less landscape water than plants from areas that receive more rainfall. Generally, plants adapted to arid environments can survive with little water and low relative humidity once they’ve been established. They have extensive root systems and/or leaves that retain water.
The following are rules of thumb on the watering needs of desert adapted plants. However, ultimately, the health and vigor of your plants is your best guide.
1. Plants that “need no supplemental irrigation once established” usually don’t need to be irrigated by the second or third summer after planting, and can usually survive strictly on seasonal rainfall.
2. “Drought-tolerant” plants can survive with three to six deep soakings during a dry summer.
3. “Regular irrigation” usually means weekly or bi-weekly for established plants during very hot weather; however, newly planted plants will need more frequent watering.
4. An 800-square-foot overseeded lawn, which is the average homeowner’s size, uses 28,000 gallons of water per year depending on the turf grass type and climate.
5. Water young plants more often, as they have small root systems and tend to dry out quickly. Older plants have established root systems with plenty of root hairs (the organs that collect the most water for the plant), so they do not need to be watered as frequently as younger plants.
6. When it’s hot, dry, and windy, plants use up water rapidly. Young or shallow-rooted plants cannot absorb wate