|
Getting your Trinity Audio player ready...
|
| Welcome to our tree column, “Ask your local arborist.” Each month, arborists from the Davey Tree Expert Company in Menlo Park discuss a tree-related topic from general care and planting tips to how trees can impact your property. If you have a tree-related question or an idea for a topic to discuss, email lifestyle@embarcaderopublishing.com or post in the comments section at the end of this column. |
The Bay Area is heading into a weak La Niña winter, which typically brings a drier-than-average season. However, the National Weather Service cautions that this year comes with a high degree of uncertainty because not all La Niñas behave the same way. Weaker events, marked by milder cooling of Pacific Ocean temperatures, often produce more unpredictable weather patterns..
Regardless of whether we experience a drier or wetter winter this year, now is the time to prepare your trees for rain, saturated soils and wind gusts and to take preventative measures to reduce the risk of weak limbs or destabilized trees failing. With smart preparation, you can help your trees withstand the region’s unpredictable months ahead.
Why November is Critical
Trees entering fall have often weathered months of summer stress: heat, drought and insects. Fall is the time when trees shift resources to their roots, preparing for dormancy.
A tree with dry soils can struggle when the rain hits. In contrast, well-hydrated roots help buffer stress during wet periods. That means deep watering before the rains begin can prevent drought stress, reduce root mortality and strengthen trees against saturated soils. Saturated soils reduce rooting strength, making trees more vulnerable to toppling or limb breakage under wind and rain.
Proactive steps to protect your trees
Prune dead, damaged or weak limbs
Once your trees shed leaves, it’s easier to see structural defects. Since the canopy is thinner, you can better identify dead wood, weak unions or rubbing branches. Pruning at this time reduces the load on branches during storms.
When pruning, remove limbs back to healthy wood, try to minimize large open wounds, and maintain correct branch angles. If large limbs or those near structures or utilities are involved, call your local Davey arborist.
Inspect for hidden defects
Some dangerous tree failures come from defects you may not see at first glance:
- Look for cracks or splits through bark or wood.
- Check for weak branch unions, where multiple branches grow too close with bark inclusions.
- Watch for root stress or exposed/heaving roots, especially near hardscapes or grading changes.
- Notice decay or cavities in trunks or major branches.
If any of these appear, an arborist can perform more advanced diagnostics or risk assessment.
Deep water before rains begin
Don’t neglect watering in fall. Trees continue to take up moisture even as they slow canopy growth. Fall hydration gives roots the moisture and reserves they need to survive dry spells and saturated soils.
Here’s a recommended rule of thumb: 10 gallons of water per inch of trunk diameter, applied slowly and deeply to reach the root zone (6-12 inches below soil).
Use methods like soaker hoses or drip systems rather than overhead sprinkling to reduce evaporation and avoid moist foliage, which can promote disease.
Mulch, nutrition and support
Apply a 2-4-inch layer of organic mulch, extending toward but not touching the trunk. This helps moderate soil temperature, retains moisture, and reduces compaction.
Light fall fertilization can support root growth, but avoid heavy late-season feeding, which may encourage new growth vulnerable to winter stress.
Bring in the pros for trees showing structural weakness, consider cabling or bracing to reinforce the trunk or limb load capacity before storms hit.
What to watch for after the first rain
Despite your best efforts, storms test every preparation. Monitor your property carefully:
- Watch for new cracks or splits in bark.
- Check for leaning, tilting, or root heave.
- Be alert to sudden branch drops or canopy changes.
- Document damage with photos and dates. This is important for insurance or arborist assessments.
Prompt removal of fallen limbs helps prevent further damage or risks to people, buildings or utilities.
Check local ordinances
If your tree is in the public right-of-way or part of the city’s urban canopy program, consult your city’s urban forestry department before pruning or treatments.
Some large or heritage trees may fall under local tree protection ordinances. Make sure to check permit requirements before major work.
Thanks for reading our tree column, “Ask your local arborist.” Each month, arborists from The Davey Tree Expert Company in Menlo Park will discuss a tree-related topic, specific to the Palo Alto area. If you have a tree-related question or an idea of a topic to discuss, email them here. If you are interested in having an arborist come to your property to assess the trees in your landscape before listing your home, call 866-923-5658 or visit www.Davey.com/menlopark.
George Reno is a local arborist at The Davey Tree Expert Company in Menlo Park, which serves communities on the Peninsula, including Menlo Park, Atherton, Palo Alto and Redwood City. Reno can be reached at 866-923-5658.
