Watering of Trees & Shrubs

One of the most important components to insure the survival of newly planted, transplanted and established trees is proper watering. Drought conditions will weaken and stress trees, resulting in stunted shoot growth, sparse foliage and higher susceptibility to insects and diseases. A watering schedule should be followed to insure the tree is receiving an accurate amount of water.

Newly Planted Trees

Proper watering is the most important component in the care of a transplanted tree. Too much or too little water can result in tree injury. Newly planted trees and shrubs may need to be watered for two to three years until their root systems become established. Large trees that have been transplanted may take longer.

For the first few months of the growing season after a tree is planted the tree draws most of its moisture from the root ball. The root ball can dry out in only a day or two, therefore it is critical to apply the water to the root ball area of the tree by either a soaker hose system or using a hose with the water rate at an extremely slow rate (to avoid runoff) and by the moving the hose periodically. The ideal amount of water per week should be in the 1-inch volume.

Residents are encouraged to water weekly newly planted trees in front of their homes to ensure their survival.

Established Trees

Even after trees are well established, they should be watered generously during periods of drought. The top 8-12 inches of the soil should be kept moist around trees during periods of drought, at least as far as the branches spread (drip line).

It is impossible to provide a formula on how much or how often to water a tree to keep the upper 8-12 inches of soil moist. The amount of water required will vary with local site conditions, but without adequate rainfall, established trees may need watering as often as every 10-14 days or 1 inch weekly. A soaker hose system or using a hose with an extremely low water rate can be used.

Watering Methods

  • If the ground is level, simply let an open hose run on the ground at an extremely slow water rate (avoid runoff) and reposition it periodically to get good distribution. A soaker hose, if allowed, is a good method.
  • If the ground slopes severely, a root-watering needle may be necessary. Insert the needle no more than 6 inches into the ground and reposition it frequently since it moistens a small area around the insertion point.

It is important not to saturate the trunk area. Keep the top 8 to 12 inches of soil evenly moist throughout dry periods.

All watering must strictly comply with all City's water conservation regulations.