Tree roots in Pomona, CA commonly lift sidewalks and driveways and find their way into old clay sewer laterals. Some root problems can be managed with careful root pruning, root barriers or replacing paving with flexible materials. Cutting large roots close to the trunk, however, can kill or destabilize a tree. When roots have badly damaged a sewer line or the tree is too big for its spot, removal and replanting is often the honest answer. For City street trees, report root problems to Public Works rather than cutting roots yourself.
Why roots lift paving
Roots grow where water and air are available. The space under a concrete slab often stays moist and has air pockets, so roots grow there and thicken. Over time, they push slabs up. Shallow-rooted species like ficus, camphor and some elms are common culprits in older Pomona neighborhoods.
Why roots find sewer lines
Many older Pomona homes have clay sewer laterals with joints that develop small cracks. Roots find the moisture and nutrients leaking out and grow into the pipe. Once inside, they spread and catch debris, causing backups. Grinding a stump does not remove roots already inside a pipe.
Options for roots under paving
- Root pruning. Cutting roots at a safe distance from the trunk. The safe distance depends on the tree size and species.
- Root barriers. Installed along a walk or foundation to redirect future roots.
- Flexible paving. Pavers or decomposed granite instead of slabs near trees.
- Ramping or grinding the concrete edge as a short-term fix.
- Removal when roots are too big to cut safely.
Options for roots in sewer lines
- Camera inspection by a plumber to find the problem.
- Root cutting inside the pipe as a short-term fix.
- Lining or replacing the lateral for a long-term fix.
- Removing the tree when it keeps reinvading the line.
When root work is unsafe
Cutting large roots close to the trunk can make a tree unstable and likely to fall, and can cause decline. As a rule, the bigger the root and the closer to the trunk, the riskier the cut. We will tell you honestly whether root pruning is safe.
Street trees
If the roots belong to a City street tree, report the problem to Pomona Public Works. Do not cut the roots of a street tree yourself. See our street tree guide.
Stumps and old roots
After a removal, stump grinding removes the stump and surface roots. Roots left in the ground will decay over time.
Replanting smart
When replanting near paving or sewer lines, choose species with less aggressive roots, plant farther from hardscape and use root barriers. Deep, infrequent watering encourages deeper roots.
Foundations
Tree roots rarely damage sound foundations directly, but they can contribute to soil shrinkage in some clay soils during drought. If you are worried about a foundation, talk to a structural engineer before cutting roots.
How to talk to your neighbors about roots
Roots do not respect property lines. If a neighbor's tree is lifting your driveway, or your tree is cracking their walk, talk early and calmly. Share photos and, if useful, a plumber's camera report. California law generally allows you to cut roots that cross onto your property, but not in a way that kills or destabilizes the tree, and cutting large roots near a neighbor's tree can create liability if the tree later falls. A shared plan, such as a root barrier along the property line or a coordinated removal, usually costs less than a dispute.
Call (909) 479-2666 to talk about a root problem.
Before any digging for root barriers or sewer work, call USA North 811 for utility marking. If the tree has to go, see tree removal and our guide to removal costs.
Common questions
Can I cut the roots lifting my driveway?
Sometimes, if the roots are small and far enough from the trunk. Cutting large roots close to the trunk can kill the tree or make it unstable and likely to fall. Have the tree looked at first. If the roots belong to a City street tree, report the problem to Pomona Public Works instead of cutting them.
Will grinding the stump fix my sewer line?
No. Stump grinding removes the stump and surface roots, but roots already inside a sewer pipe stay there until they decay or a plumber removes them. Have the line inspected with a camera, and talk to a plumber about cutting, lining or replacing the lateral.