Affected trees may appear perfectly normal and resume growth in the spring using stored food energy. Established trees should be watered two times a month September and October and once a month from November to March. Trees that don't get enough water can suffer stress and drought injury. Trees may be weakened and all or parts may die in late spring or summer when temperatures rise. The signs of drought stress often don't show up until the heat of the following summer, which then makes trees more susceptible to pests and disease.
Important factors to consider when watering trees:
-Newly planted trees that have been planted within the last 3 years are more susceptible to damage from drought conditions and need to be watered more frequently than established trees. Water them to a depth of 24 inches three times a month in the fall and twice a month in the winter.
-Evergreen trees lose water through their needles in the dry winter air. They need more stored-up water going into the winter season to make up for that. Cold, dry winds can strip water from evergreens faster than their roots can absorb it. That is why it is especially important to provide enough water in the fall and during dry spells in the winter.
-Even though they lose their leaves, deciduous trees should also not get too dry in the fall and winter. Water acts as an insulator for both the tree and soil. Soil that stays moist will be warmer. Likewise, plant cells that are plump with water will be less susceptible to damage from the cold. Water deciduous trees to a depth of 24 inches twice a month during the fall and once a month in the winter.
-When watering any tree, remember to apply water out to the edge of the tree’s canopy drip line. Most established trees have a root spread equal to their height and beyond. Water deeply and avoid spraying foliage. Watering to the right depth depends on your specific soils, so you will want to measure how much water it takes your soils to reach 24 inches deep.