Pasadena Water & Power

Healthy Trees

 Row of Trees Illustration 1 

Trees and water are both precious resources. Trees make our houses feel like home. They also improve property values, clean our water and air, and even make our streets safer and quieter. When we use water wisely and maintain our trees carefully, we enjoy a wide range of befits at a low cost and with little effort. The following tips and information are courtesy of the Pasadena Public Works Department and the California Urban Forests Council.


  • Water trees slowly, early in the morning or after the sun has set;
  • Use soak hoses and drip irrigation to water trees;
  • Water young trees once per week (slow, deep watering), approximately five gallons each time; and
  • Water mature trees once per week in the “drip zone” area directly beneath the outside edge of the foliage of the tree.


  • Layer three to four inches of mulch in a five-foot area, two inches from the base of tree to reduce water evaporation, keep soil cool, and deter weeds, promoting healthy soil.
  • Free mulch available to Pasadena residents! See below for details.


  • Do not fertilize trees which can burn the tree’s roots under drought stress;
  • Do not prune live branches as it reduces the tree capacity to grow once it rains; and
  • Avoid digging under the canopy of tree which can kill small roots, reducing the tree’s capacity to absorb water.


Free Mulch Program
The Pasadena Public Works Department offers free mulch to Pasadena residents. New loads of mulch will be available on various dates from February to November. Learn more.

"Shade Trees" Rebate
PWP electric customers may be eligible for rebates through the Home Energy Rebate Program for planting any one of 37 species of shade trees. Planting deciduous (shade) trees around your property can reduce the amount of energy you will use for cooling in the summer, while letting in the sun's warming rays during winter. In addition to their energy-saving benefits, trees provide privacy, prevent soil erosion and beautify your environment. To download the rebate application or view a list of qualifying trees click here.

San Gabriel River Discovery Center Authority
The Discovery Center promotes the importance of protecting our water resources within the San Gabriel River Watershed, and provides educational and outdoor experiences for people of all ages. To download their fact sheet with tips for climate resilient and healthy trees and landscapes click here

Inland Urban Forest Council
For more information about how to care for trees during a drought please visit the Inland Urban Forest Council or download their tip sheet titled, "Prioritize Watering Trees During a Water Shortage."

Water Usage Gauge