Winter is often seen as a quiet season for yard work, but for trees — especially in the Lake Arrowhead, Crestline, Big Bear Lake, and surrounding San Bernardino Mountain communities — it’s one of the best times for important tree care. At Cumorah Tree Service, we’ve proudly served our mountain neighborhoods since 2003 with expert trimming, removal, stump grinding, weed abatement, and more, and we’ve seen firsthand how winter tree work can set the stage for healthier, stronger trees in spring and beyond. 
Even though trees aren’t actively growing in the colder months, their dormant state provides unique advantages for maintenance and safety.
Why Winter Tree Work Matters in Mountain Climates
In the winter, most deciduous trees enter dormancy, meaning their energy production and sap flow slow down significantly. This reduced activity makes tree trimming and pruning less stressful for the tree, helping cuts heal more effectively once spring arrives. Without the heavy foliage that hides internal structure during the growing season, our arborists can see weak, crossing, or hazardous limbs more clearly, allowing for safer and more precise pruning. 
For homeowners in Lake Arrowhead, Running Springs, Skyforest, and nearby mountain areas, winter can be the ideal season to plan tree work that promotes long-term health and resilience.
Best Winter Practices for Tree Trimming and Pruning
1. Focus on Structural Tree Care
Winter is a great time to remove dead, damaged, or diseased limbs that could pose a risk during winter storms or spring winds. With leaves off most trees, this type of structural pruning becomes far easier and safer to accomplish. 
2. Improve Tree Health Before Spring
By trimming in winter, we help trees concentrate their energy in the right places. Removing problematic growth during dormancy allows trees to heal more efficiently and allocate nutrients toward stronger branches and healthier development once the growing season starts. 
3. Minimize Sap Issues for Conifers
Many homeowners in the mountains have beautiful pine, fir, and evergreen trees. While summer pruning can sometimes trigger excessive sap flow — particularly problematic with pines — dormant-season trimming usually avoids this issue because sap movement slows in colder temperatures. This means cleaner cuts and less mess on your property.
Why Avoid Certain Tree Work During Winter Frost
It’s worth noting that winter tree work isn’t always about heavy pruning. In periods of deep frost or extreme cold, wood can become brittle, and open cuts may be more vulnerable to damage. For that reason, experienced professionals like our team at Cumorah Tree Service always consider weather conditions and tree health before proceeding with any job. Proper timing and temperature awareness help protect against unnecessary stress and ensure the best outcomes for your landscape.
Winter Tree Care Beyond Pruning
In addition to pruning and trimming, winter is a good time for tree inspections and preventative work. Homeowners in the San Bernardino Mountains should watch for:
• Weak limbs hanging over homes or driveways
• Storm damage from autumn winds or early snow
• Branches interfering with power lines
• Signs of disease or decay
Addressing these concerns during winter can reduce the risk of costly damage and help protect your home, vehicles, and family members.
Local Expertise You Can Trust
At Cumorah Tree Service, we’ve been caring for trees throughout the San Bernardino Mountain communities for over 20 years. We understand the unique challenges mountain climates bring — from seasonal storms to sap-producing evergreens — and we tailor our services accordingly. Whether you need winter pruning, tree trimming, stump grinding, or full removal, our professionals bring safety, precision, and respect for your property to every job.
Schedule Your Winter Tree Service Today
Keep Your Trees Healthy This Winter
Winter can be an ideal time for tree maintenance — but only when done correctly. If you’re in Lake Arrowhead, Crestline, Running Springs, Skyforest, or Big Bear Lake and you want your trees to thrive year-round, now is a great time to schedule your wintertime tree work with a trusted, local arborist.
Call Cumorah Tree Service today at (909) 336-4637 or request a quote online to get your winter tree care on the calendar. Our family-owned team is here to help your trees stay strong, healthy, and safe — no matter the season.