 to cover, air temperature and wind speed. You'll need about 50 gallons of water to apply 1 inch of water to a 100-square-foot area.
Leaf scorch on trees and shrubs, which appears as browning of leaf edges, is very common in most dry summers. Couple that with the spring freeze injury and many trees and shrubs are dropping leaves before they turn brown.
While minor cases of leaf scorch and leaf drop are not terribly harmful to the plant, prolonged lack of moisture can spell disaster for landscape plants. Young and newly established plants are most susceptible to the dry conditions, but even established plants may reach a critical point during prolonged drought. Branch and root dieback make plants more susceptible to winter injury. Plants already stressed by other factors may succumb to severely dry soils.
Keep in mind that next year's growth will be determined by buds that form this summer and early fall. Flower buds for many spring-flowering and fruiting plants will also be developing during this time. So even if your plants aren't showing any symptoms now, the damage may become apparent next season.
Watering landscape and fruit plants should be aimed at where the roots naturally occur. While these woody plants have some roots that grow very deep, most of the feeder roots that are responsible for water uptake grow in the top 12-18 inches of soil. Most feeder roots are concentrated below the dripline of the foliage canopy and outward, not up close to the trunk. Allow water to thoroughly soak the target area by applying water at a slow enough rate to allow penetration rather than wasting water as runoff. Apply the water no faster than 1 inch per hour. As with annual plants, applying mulch will help prevent moisture loss due to evaporation.
The ideal time to water is before 8 a.m. This makes maximum use of water while allowing foliage to dry. Midday watering when temperatures are high, sunshine is strong and winds are brisk wastes substantial water. Watering during the evening or overnight can make plants more susceptible to disease infection by providing the surface moisture needed by fungi and bacteria. Of course, if your community imposes restrictions on water use, ideal watering practices may not be possible. If your community is under restricted water use, it is certainly better to water when permitted than not water at all.
Household gray water, such as that leftover from the bath or washing dishes can be used, within limits, if fresh water is not available. Detergents in gray water contain salts that can accumulate to harmful levels in the soil. Use gray water only as a last resort, and use it as sparingly as possible to avoid salt build up. Never use gray water on edible crops or on containerized plants.