The best time to prune most shade trees in Pomona, CA is late fall through winter, when trees are dormant or slowed down, pests are less active and birds are not nesting. Flowering trees like jacaranda are best pruned after they bloom. Palms are usually trimmed in late spring or summer. Bird nesting season runs from about February through August, and active nests are protected, so pruning during those months needs a nest check first.
Fall: prepare for wind
Fall is the time to thin heavy canopies and reduce long, end-weighted limbs before Santa Ana winds arrive. That is especially important for:
- Eucalyptus, which drops limbs in heat and wind.
- Chinese elm and pepper trees, with weak branch unions.
- Pines with heavy, extended limbs.
It is also a good time to lift limbs off roofs and clean gutters for defensible space.
Winter: the main pruning season
Most deciduous and many evergreen shade trees are best pruned in winter:
- Sycamores, before spring leaf-out.
- Fruit trees such as apricot, plum and peach, for shape and fruiting wood.
- Camphor and ficus, for thinning and clearance.
- Oaks, lightly, in the cooler months.
Winter is also when you can see the structure of deciduous trees clearly.
Spring: light work and nest checks
From about February on, birds start nesting. The federal Migratory Bird Treaty Act and California Fish and Game Code protect active nests. We check trees before cutting and leave active nests alone. Spring is a good time to:
- Remove deadwood that became obvious at leaf-out.
- Do light corrective pruning on young trees.
- Cut dry brush after the rains, before the heat.
Summer: palms and flowering trees
- Palms. Trim dead fronds and flower stalks in late spring or summer. See palm trimming.
- Jacaranda. Prune right after the summer bloom.
- Crape myrtle. Light shaping, never heavy topping.
- Avoid heavy pruning on hot days, which stresses trees and can sunburn exposed bark.
Watering through the seasons
- Summer. Deep, slow watering at the edge of the canopy every few weeks for mature trees.
- Fall. Keep watering until rains begin.
- Winter. Usually rainfall is enough, unless it is a dry winter.
- Spring. Resume deep watering as the weather warms.
How much to prune
As a rule, do not remove more than about a quarter of a healthy tree's live foliage in one visit. Less is often better. Do not top trees. See our tree trimming service.
Signs pruning should not wait
Some problems should not wait for the ideal season: a cracked limb over the house, a dead limb over a walkway, a branch rubbing the roof in wind. Call us if you see those. For anything near a power line, call SCE at 1-800-611-1911.
Quick calendar
- October to December: thin for wind, lift off roofs.
- December to February: main pruning season.
- February to August: nest checks, light work.
- May to August: palms, jacaranda after bloom.
Call (909) 479-2666 to get on the schedule.
Young trees
Young trees benefit from light structural pruning every season or two while they are setting their shape. Choose one strong central leader, remove competing stems and space the main limbs along the trunk. Small cuts on a young tree prevent big cuts on a mature tree later, and they heal quickly. Winter is ideal, but light structural work can be done any time outside the hottest weeks.
For palms, see our palm care guide, and for wind damage, the after-windstorm checklist. The UC IPM program has species-specific pest and care notes.
Common questions
Can trees be pruned during nesting season in Pomona?
Yes, with care. Active bird nests are protected by federal and state law, so before cutting from about February through August, we check the tree and leave active nests alone. That can mean delaying part of the work. Urgent safety pruning can still happen when no active nest is affected.
When should I trim a jacaranda?
Right after it finishes blooming in summer. Pruning earlier removes the wood that will flower. Keep cuts small, because jacarandas decay easily from large wounds. Thinning and light shaping are better than heavy cuts. If a jacaranda has a dangerous limb, deal with that whenever needed.
Is summer a bad time to prune?
Heavy pruning in summer heat stresses trees and can sunburn newly exposed bark. Light pruning, deadwood removal and palm trimming are fine in summer. Save major thinning and structural work for late fall and winter when you can.