Tree Care Resources

One of the best ways to help grow our urban forest is to plant more trees! Our non-profit partner Canopy has many resources (listed below) to help you select the right tree for the right site on your property. A few of the factors you should consider when selecting a tree species and planting site include: available soil space, overhead utilities, underground utilities, surrounding vegetation, and distance from structures. 

This video from Canopy demonstrates how to properly plant a tree.

Other Tree Planting Resources

• Canopy Tree Library
• How To Plant a Tree (Canopy) 
• Identify Your Tree (Cal Poly)

All trees need water to thrive, even drought tolerant trees. Water young trees once a week, and water mature trees monthly or bi-monthly, particularly during hot, dry weather. Be sure to water trees deeply (the top 12+ inches should be wet) and water away from the trunk.

Established native California oaks (Quercus lobata and Q. agrifolia) should not be watered in the warm summer months.

Tree Watering Guidelines (Canopy)

Save Our Water & Our Trees (Canopy)

Spread a layer of organic mulch (e.g. wood chips) beneath trees.  Inorganic mulches such as rocks and decomposed granite (DG) do not provide the same benefits that organic mulches do. 

Properly applied mulch offers many benefits to trees by:

• Helping maintain soil moisture, reducing the need for frequent watering
• Controlling weeds
• Regulating soil temperature
• Reducing soil compaction
• Improving the soil’s structure, fertility, and drainage over time

The mulch layer around trees should be 2-4” thick and the base of the trunk/root collar should remain exposed to prevent trunk rot. Avoid creating a 'Mulch Volcano'.

Trees Are Good-Proper Mulching Techniques PDF

Mechanical damage from mowers or string trimmers can cause serious damage, especially to young trees. Wounds are easily invaded by disease-causing pathogens and insects. Keep turf away from the base of trees. Also, take care when opening car doors near trees and do not lock bikes or attach other items to trees. 

Trees grow best in uncompacted soil with about 50% pore space. This pore space allows for infiltration of air and water. Porous soil has better drainage and oxygen flow, and promotes root growth. Avoid driving and parking on the root zone of a tree. Vehicles, heavy machinery, or materials should not be stored beneath a tree.

*No new paving (concrete, asphalt, pavers, etc.) is permitted within 10 feet of a public tree (PAMC 8.04.020)

Residents see the public street trees in front of their home daily and are often the first to notice changes in tree condition. Please report changes in condition to public trees including damaging insects, diseases, physical damage, illegal pruning, etc. by calling (650) 496-5953 This will help us address the issue(s) in a timely manner.