Tree Watering Guide

According to the Inland Forest Council and other experts, our valuable trees are to be watered deeply, especially in months without rainfall.
Here are some tips on watering: Tree Watering Guide

  • Soak the root system every 4-6 weeks with a slow running hose or move a 5 gallon bucket of water with a hole in the bottom around the tree’s canopy.
  • Place a bucket under your shower while the water warms and use that captured water on trees.
  • Mulch under your tree to reduce evaporation, but avoid the tree trunk.
  • Visit http://inlandurbanforestcouncil.org/project/waterwise-tree-care for more information.

What Does a Tree Under Drought Stress Look Like?

Drought stress symptoms can show suddenly or take up to two years.  Typical symptoms include leaf wilting/curling/yellowing.  Deciduous trees may develop “scorch” which is browning along edges or between leaf veins.  Or leaves may be smaller than normal or drop prematurely. Evergreen needles may turn yellow, red, or brown, and may discolor all the way to the twig.

Best Management Practices for Efficient, Effective Tree Watering

  • DO water to 8- 12” below soil surface is recommended. (You can use a screwdriver to probe down. If the soil is moist and sticky, wait more days. If it’s dry and crumbly, water deeply).
  • DO saturate the soil around the tree within the drip-line (outer perimeter of branches) to give water the shortest path to roots.
  • DO water several feet beyond drip-line on all sides of the tree for all evergreens (such as cypress, pines).
  • DO water slowly, dispersing flow of water to encourage deep watering. Short, intense cycles tend to encourage shallow root growth.
  • DON’T dig holes in the ground in an attempt to water deeper, as this causes roots to dry out.

Other Tree Care Tips

  • Use organic mulch around your tree to increase soil moisture, while keeping it at least 6” from the trunk.
  • Consult/use a professional when pruning your trees; don’t over prune.
  • Avoid fertilizing trees experiencing drought stress, as salts may further tax the tree.

Additional Tips for Watering Young Trees

  • For the first three years, young trees need slow, deep watering during the dry season. This is usually from April to October, but may be longer.
  • On average, your tree will need 15 gallons of water per week.
  • Water 2-3 times per week, depending on how hot and dry it is outside.

Additional Tips for Watering Mature Trees

  • Mature trees need deep watering that penetrates at least 2-3 feet.
  • Watering during our rain-less months varies greatly depending on the tree species, temperatures and tree location, as well as soil type. Click here for a table of water needs for mature trees.
  • In general, established drought-tolerant trees may need occasional watering at 1-2 month intervals in the dry season. California native oaks, California laurel, cork oak, and Chinese pistache can be damaged and short-lived with too- frequent summer watering.
  • Moisture adapted trees such as birches, redwoods, magnolias and red maples may need deep watering throughout their lives to look their best. They benefit from an occasional deep watering to at least one foot 1-2 times a month.
  • Poorly adapted trees such as Monterrey pine, Leyland cypress and giant sequoia are prone to insect damage and diseases in hot dry interior areas, regardless of how much water they receive.

How to Water

For mature trees, a soaker hose (found at garden stores) that circles the drip line is best. See below for more details on using a soaker hose. Other methods include timed hand watering using a spray attachment on the end of a standard hose, or moving around the drip-line a slow running hose or bucket with a hole in the bottom.

  • Young trees can be hand-watered by the above systems but especially benefit from use of watering bags (found online) delivering higher volume of water at same slow rate. (Treegator is one water bag manufacturer).
  • Remember – any deep watering is better than no water.  The water trees receive through lawn irrigation is not sufficient for most trees and can lead to shallow, more unstable roots.​

Why Trees are Important​

If you lose a large tree, you’ve lost:

  • Valuable shade canopy.
  • Property value.
  • Important wildlife habitat value.
  • Energy conservation- a single large tree cools  as much as 10 room air conditioners.

For more information

http://www.treesaregood.org (International Society of Arboriculture)

http://sactree.com/saveourtrees (Sacramento Tree Foundation)

https://www.treepeople.org/resources