Should We Stop Planting Trees in a Drought? No.
Jan Scow and Garrett Clifford
With our current drought and the continuing uncertainty about future rainfall some in Ojai are discussing the legitimacy of planting new trees as they require watering to become established and survive; others are wondering how to treat their existing established trees. Ojai Trees recently addressed these issues in a talk by arborist Jan Scow, an Ojai Trees board member and Board President Garrett Clifford. The two came down not surprisingly on the side of continuing to plant trees and learning to properly care for them. The following is an outline of their talk. If you did not attend and have questions you may email Scow at info@janscow.com
1. What is happening?
a. Warmer weather and less dependable rainfall
b. Watering restrictions and loss of existing older trees
2. What are some of the ways we know trees are beneficial?
a. Cooling by shade and evapotranspiration (like a swamp cooler)
b. Lowered utility use and inherent reduction of CO2 emissions
c. Habitat for hundreds of species (birds, insects, fungi, mammals, etc.)
d. Reduction of air pollution (trapping particulate matter)
e. Carbon sequestration (intake CO2, build wood)
f. Reduction of crime
g. Improved mental health and enhanced healing ability
h. Reduced water runoff during storms (interception), recharging water table
i. Reduced soil erosion
j. Longer life of asphalt street
3. How do we successfully establish new trees?
a. Proper species selection
i. Not “thirsty” trees such as birch, magnolia (Check out our updated Ojai Tree Guide for species recommendations).
ii. Look at the newly updated CFMP
b. Proper planting which includes
i. Location (right tree for the right place)
ii. Soil mix
iii. Planting depth
iv. Removal of nursery stake
v. Building a proper basin
vi. Mulching (use of arborists chips)
c. Proper watering
i. Flood basin
ii. Maintain basin
iii. Expanding watering zone as tree becomes larger, drip
4. How to treat established trees
a. Some trees are no longer suitable for planting in our soils and climate
i. Magnolias, birch, alders, coast redwoods, etc. are examples
ii. They may require an unreasonable amount of water to stay viable
b. For existing trees
i. Mulch and/or retain natural leaf litter
ii. Water appropriately Drought (tolerant trees vs. “thirsty” trees)
Where are the tree roots?
How much water?
When to water?
what can be done to maximize the potential for success (of all trees, new and old) while limiting unnecessary water use.
