Last updated: Mar 31, 2026
This guide covers tree trimming best practices, local regulations, common tree species, and seasonal considerations specific to Columbia, MO.
Late winter is the primary pruning window for mature hardwoods on heavy clay soils and steep hillsides. In this climate, late-February through early March often offers the most favorable balance of cold dormancy and before the growth surge, making it easier to see branch structure against a bare canopy. However, late-winter ice, wet snows, and freeze-thaw swings can push back schedules. If a heavy ice event terminates growth or rattles branches, postpone nonessential pruning until conditions stabilize and bark is dry enough to handle without slipping on slopes. On steep terrain and erosion-prone sites, prioritize removing weak, crossing, or dead wood only when the ground is firm and you can safely work from stable footing. If soils are saturated, resist trenching or wading into the root zone to fetch pruning cuts-soft ground increases the risk of soil compaction and root damage.
As buds begin to swell and days warm, take a cautious, site-informed approach. In this period, the goal is to shape and reduce only where needed, without inviting excessive new growth that would heighten drought stress later in the season. On clay soils, heavy canopy reductions trigger larger leaf surfaces that demand more moisture; in a city with hot, humid summers, that extra load can push trees toward heat stress if the canopy is reduced too quickly. Plan any decisive structure work-especially on mature codominant leaders or branches with weak union-for a day with moderate temperatures and a light breeze to avoid sudden heat buildup in exposed cuts. On hillside yards and near creeks, consider smaller, incremental steps rather than one large reduction; this helps maintain soil moisture balance and minimizes erosion risk along the root zone.
Once heat arrives, heavy canopy reductions become riskier on Columbia's clay soils and on steep sites. The combination of high evaporative demand and limited soil moisture can stress trees quickly if too much leaf area is removed at once. If a structural adjustment is unavoidable, aim for small reductions or targeted removal of dead or defective limbs only, and do so in the cooler early morning hours. Do not attempt large cuts during peak heat or after drought periods, when sap flow is high and wounds can take longer to dry. For creeks and hillside corridors, prioritize maintenance that reduces localized shedding risk, such as removing branches that overhang paths or driveways, but avoid dramatic thinning that opens the crown to sun-scald or creates uneven wind loading. Always monitor soil moisture and adjust watering accordingly after pruning in drought-prone spells.
Fall leaf drop on Columbia's large deciduous canopy makes final structural shaping harder to judge until leaves are down. Plan any last-minute structural work for late October through early November, when most leaves have fallen and the tree's branching pattern is clearer. Yet be mindful of early cold snaps that can solidify pruning wounds before winter dormancy-wait for a stretch of steady nights near or below freezing to minimize regrowth and decay risk. On slopes and near creek edges, fall pruning should emphasize correcting any hazardous branches while the tree is still freckled with dry days, but avoid aggressive cuts that expose fresh wounds to late-season moisture fluctuations. If a major reduction is still needed after leaf drop, break it into two lighter sessions spaced several weeks apart to let the tree recover gradually and to reduce soil disturbance during wet autumn periods.
This approach aligns with Columbia's climate quirks-late-winter ice, wet snows, and freeze-thaw swings shaping the pruning calendar; hot, humid summers demanding restraint on canopy reductions; and fall leaf drop complicating final shape assessments on large deciduous networks.
Many neighborhoods feature mature oaks, maples, elms, basswood, and coffeetree perched on rolling terrain rather than flat lots. That means pruning work often has to contend with slope changes, retaining walls, and creek-adjacent ground. The mismatch between tree height and hillside access amplifies risk for both the tree and the crews. When a limb overhangs a swollen drainage ditch or leans toward a steep yard, the decision to prune becomes a careful balance between improving structure and avoiding unnecessary damage to nearby soil and foundations. In Columbia, where the landscape transitions from glaciated plains toward the Ozark border, these features are common and can complicate even routine thinning or canopy shaping.
Boone County's heavy clay soils soak up moisture and stay slick after rain, which directly affects how you approach pruning on slopes. A bucket truck may not seat reliably on a clay hillside, and the ground beneath can shift under load, lifting feet or slipping if the slope is damp or uneven. In practice this means tighter planning, more emphasis on ground-based work when conditions are damp, and sometimes choosing smaller, more frequent adjustments rather than large, dramatic cuts. When soil is slick, large cuts that leave exposed wounds or sudden weight shifts in the canopy can increase the chance of branch failure during or after the job. Expect quieter, more gradual canopy work on hillsides rather than dramatic, single-session overhauls.
Seasonal timing matters especially for mature hardwoods on these sites. In Columbia's climate, late winter to early spring (before sap begins in earnest) is often the window for structural improvements, as this minimizes sap loss and reduces the exposure of fresh cuts to temperature swings. However, on slopes with clay soils and ground moisture lingering after rain, it's prudent to align pruning with a stretch of drier days to reduce soil disturbance and compaction near the root zone. Avoid heavy pruning in periods of heavy weight on the soil from rainfall or from nearby irrigation, as the combination of slick ground and exposed cuts can invite struggles with bark or minor wound exposure on steep terrain. If the canopy carries weight over walkable zones or near driveways perched on a slope, plan to perform smaller, incremental removals to keep drop zones under control and minimize soil disruption.
On slopes, large, single cuts can destabilize a limb or shift the balance of the whole crown, increasing the risk of tearing bark or splitting branches along the cambium. For trees already contending with soil movement or root zone edging from retaining walls, the safest approach is to focus on removing deadwood and crossing branches that rub or crowd the interior, followed by selective thinning to improve air movement and light penetration without overburdening the roots. When limbs overhang a creek corridor or fragile bank, every cut should consider potential downstream impacts, including soil erosion and debris flow after a storm. The goal is steady, thoughtful gains in structure and health rather than bold, sweeping changes that leave the tree more vulnerable on a hillside in a Columbia rainfall pattern.
Tiemann Tree Source
(573) 424-5409 tiemanntreesource.com
5880 N Oneal Rd, Columbia, Missouri
5.0 from 238 reviews
Tiemann Tree Source is owned and operated by Matt Tiemann, founder of Resource Tree & Land and a long-time local arborist serving thelumbia, Missouri area since 2010. After years of building Resource Tree & Land into a trusted name in tree care, Matt launched Tiemann Tree Source to reflect a more focused, boutique approach to tree planting and long-term plant health care. This shift allows for more detailed, hands-on, and personal care for each customer, with every project receiving direct attention from the owner. While the name has changed, the experience, values, and commitment to the community remain the same. Tiemann Tree Source carries forward the same deep arboricultural knowledge, accountability, and long-term mindset.
Tree Wizard
(573) 442-1838 treewizardmo.com
1489 US-40, Columbia, Missouri
4.9 from 88 reviews
We are a professional tree service company that specializes in a number of different services, and we have been assisting our customers since 2002. Our skilled team has experience with numerous kinds of situations, and we can work under any conditions. Being trained experts, we have managed to improve our methods and tree service to world-class levels. Our company is fully licensed and insured, and we have a 24 hour emergency service, available at your convenience. We are aware that it is impossible to predict when the need for our assistance may occur, so we are always prepared and ready to respond. OVER 20 YEARS OF EXPERIENCE!
Voss Landscape & Tree Service
(573) 268-3947 www.vosslandscape.com
8501 N Hwy Vv, Columbia, Missouri
4.8 from 82 reviews
We realize that well trimmed trees and great landscapes do not happen on their own! Over the years, we have helped our customers maintain and improve their property, solve problems, and create new spaces. Our priority is to provide a professional service by doing the job correctly and paying attention to detail in our work. We also know that customer service goes a long way so we do our best to make sure that your requests and your property get taken care of.
Hill Tree
(573) 823-4914 www.hilltreeco.com
509 Hunt Ave, Columbia, Missouri
5.0 from 15 reviews
Hill Tree LLC is your trustedlumbia, Missouri tree service. We provide comprehensive tree care, including safe removal and trimming, land clearing for new beginnings, and complete stump grinding to ensure a flawless finish.
The Mowing Magician
(573) 234-0897 www.themowingmagician.com
10020 Interstate 70 Dr SE, Columbia, Missouri
4.6 from 55 reviews
Transform your outdoor space into a breathtaking landscape with The Mowing Magician. Since 2019, we’ve specialized in comprehensive lawn care, tree services, and landscaping to elevate homes in the Columbia, MO area. Our team offers a full spectrum of services, from expert bush and hedge trimming to meticulous mulch installation and leaf removal. As a year-round partner in property maintenance, we also provide professional snow removal to keep your grounds pristine throughout every season. Discover the magic of a beautifully maintained property.
Cevet Tree Care
(573) 881-2466 www.cevettree.com
5711 N Creasy Springs Rd, Columbia, Missouri
4.6 from 27 reviews
We provide tree care for Central Missouri. We have been doing that for almost 30 years.
Nelson's Tree Service
(573) 268-7322 nelsons-tree.com
114 Clinkscales Rd, Columbia, Missouri
4.4 from 81 reviews
Nelson's Tree Service is a Locally owned and family operated business that has been serving thelumbia, MO area for the past 15 years. We strive for 100% Customer Satisfaction and are fully licensed and Insured. We provide the following services for Residential andmmercial properties: Tree trimming Tree Removal Tree pruning Land and Lot Clearing Stump Grinding / Removal
Sky High Tree Service
(573) 268-5609 www.skyhightreeservice.org
4001 Mamba Dr, Columbia, Missouri
5.0 from 10 reviews
Reach new heights with Sky High Tree Service! We're passionate about providing professional and caring tree services throughoutlumbia, MO. Specializing in tree removal, no job is too big or too complex. We take pride in our work and dedicate ourselves to ensuring your satisfaction. Trust Sky High Tree Service to handle all your tree needs with expertise and a commitment to excellence.
Mid-State Grading
(573) 808-0970 www.mid-stategradingllc.com
12120 S Rt N, Columbia, MO
4.9 from 10 reviews
Mid-State Grading specializing in Drainage Solutions, Excavation, Land Grading, Land Clearing, Erosionntrol and Dump Truck services. Our expert team ensures your property attains enhanced beauty and functionality, meeting all your drainage correction, land management & landscaping needs with precision and care. We pride ourselves on delivering reliable and efficient services that transform your property. Choose Mid-State Grading for expert solutions that address every aspect of your landscape, from innovative drainage systems to comprehensive erosion management, ensuring your property is as resilient as it is beautiful.
TruGreen Lawn Care
(833) 418-5004 www.trugreen.com
5651 E Missouri 163, Columbia, Missouri
4.0 from 188 reviews
TruGreen provides local, affordable lawn care in the Columbia area, including aeration, overseeding, fertilization, weed control, and other services tailored to your lawn's needs. We also offer tree and shrub care as well as defense against mosquitoes and other outdoor pests. We believe life should be lived outside, and our tailored lawn plans and expert specialists help us serve our Columbia community and loyal customers every day. Place your trust in America’s #1 lawn care company by calling TruGreen today at 833-418-5004.
Columbia Tree
(573) 242-5335 www.columbiatreeco.com
113 Elk Dr, Columbia, Missouri
5.0 from 7 reviews
Columbia Tree provides high level tree services in the Columbia, MO area. Our services include tree removal, tree trimming/pruning, and stump removal. We also offer 24/7 emergency tree service. For a free estimate, call us today!
SER Tree Service
5941 N Creasy Springs Rd, Columbia, Missouri
4.3 from 6 reviews
A decade of experience in the tree industry. Have dealt with everything from storm damaged trees to trimming trees off of houses and such to completely removing trees.
In Columbia, mature trees that grow along streets, sidewalks, and easements can be tied to public infrastructure even when they sit on private property. While pruning on private property generally does not require a permit in Columbia, work involving street trees or public right-of-way trees is subject to city oversight. This distinction matters because the line between private and city-managed trees can be thin where roots and branches intersect the sidewalk, curb, or utility corridors. If a tree is near a street, gutter line, or city easement, assume it is in city hands unless you've verified otherwise with the city. You want to avoid accidentally trimming a tree that the city maintains or that supports street visibility and safety.
Columbia has an established municipal forestry function within city government, so homeowners need to distinguish private trees from city-managed trees near streets and sidewalks. When branches overhang sidewalks, driveways, or public right-of-way signage, the city may have an interest in keeping sightlines clear and limbs away from utilities. Pruning with the goal of maximizing curb appeal can quickly step into a zone where city oversight applies. Before you touch any limb or root that seems to connect with a street light, a storm drain, or a sidewalk embankment, verify the status of that tree with the city. Avoid assuming a branch is purely private if it sits over a public path or crosses into the public spacing.
Trees tied to public infrastructure should be approached with extra caution, because improper cuts can affect street safety, drainage, and the integrity of the sidewalk or utility lines. In hilly, erosion-prone terrain with heavy clay soils, stakes and anchors may interact with root systems near the right-of-way. If a branch appears to be leaning toward a curb or sidewalk, or if pruning could alter drainage patterns toward a street embankment, pause and check with the city before cutting. The risk of inadvertently destabilizing a tree that supports a street or sidewalk is real in Columbia's climactic swings, especially on steep slopes where soils tire quickly after heavy rains.
First, identify whether the tree is within a city-managed space or on private land with public-adjacent features. If the tree touches or shadows a sidewalk, street, or utility corridor, contact the city to confirm its status. Keep notes about the tree's location, height, and which limbs you're considering removing. Where branches extend into the public space, you should confirm that the action is appropriate and allowed. This careful approach helps preserve the balance between a homeowner's curb appeal and the city's responsibility for street trees along Columbia's steep, clay-soil hillsides.
Spring growth surges in Columbia quickly close clearance around service drops and neighborhood lines after the dormant-season pruning windows pass. If a branch runs close to a power line or along a service drop, every week counts. When spring greens out, branch movement increases and pushes limbs into risk zones you rely on for power and utilities. Delays aren't just inconvenient; they raise the chance of arcing, outages, or damage to the service drop during storms. You must act before the first warm spell that wakes new growth.
Late-winter weather delays can compress the local scheduling window for line-adjacent trimming before spring growth accelerates. Freeze-thaw cycles, ice or snow, and brief warmth can shove crews into a tight, missed opportunity. If you miss that window, you're waiting through another cycle of rapid growth and more branches encroaching on lines. In older neighborhoods with heavy canopies, this pressure is felt even sharper because big limbs over driveways and roofs extend further into utility corridors. Plan ahead and flag risky limbs now so crews aren't forced to improvise under spring rush.
Older established neighborhoods with large deciduous canopies are more likely to have branch conflicts over driveways, roofs, and overhead lines. Those mature trees often use the same vertical space that utilities require, especially in hillside layouts with steep drops and creek flats. Heavy clay soils plus steep terrain mean redirected growth and limb sway can bring limbs into contact with wires after storms. The risk isn't just from storms; routine powering and trimming cycles can create sudden gaps in clearance if a branch tip suddenly grows into a line.
Inspect the perimeter of service drops and the most-used lines on your street from a safe position. Look for branches that have encroached within a few feet of lines, especially on taller trees or those with rapid annual bearing. In the depth of winter, prune any obvious overhangs that could swing into lines as temperatures rise and sap flows resume. For driveways and roofs, measure clearances and identify limbs that routinely flex toward utilities in windy weather. Note areas where a single storm could push a limb into a line; prioritize those for early, targeted trimming. When scheduling, communicate your priority zones clearly to the crew so the most hazardous intersections get the fastest attention. Acting now reduces the chance of cascading outages and costly emergency trimming later.
These companies have been positively reviewed for their work near utility lines.
Central Missouri weather exposes Columbia trees to both winter ice loading and severe warm-season thunderstorms. Broad-crowned hardwoods common in Columbia can develop heavy end weight that becomes a failure risk during ice accumulation or strong convective winds. When a storm line moves through Boone County, a few limbs can fail suddenly, leaving roofs, cars, and sidewalks exposed to falling debris. In steep yards above creeks and along hillside streets, ice loading can push whole branches toward the ground, triggering additional tension in adjacent limbs and increasing risk of cascading failures. In these conditions, damaged canopy fragments may land on driveways, sidewalks, and utilities, creating urgent safety hazards for households and neighbors.
If you notice ice forming on branches or hear creaking sounds in mature limbs, step back from under the canopy and avoid underhangs near streets and driveways. Do not prune during an ice event; instead, inspect from a safe distance after thaw. If a limb appears to pose an imminent danger, contact a qualified arborist right away to assess whether removal or bracing is necessary. For overhangs that shield homes or utilities, consider temporary measures such as rerouting pedestrian paths and keeping people clear of the drop zone until professionals arrive. Keep a phone handy to document locations of damaged limbs, and prepare a quick plan for evacuation routes around the worst risk zones if a limb starts to fail unexpectedly.
After the system passes, evaluate damage from ground level only. Do not climb onto a damaged tree or stand beneath a cracked limb. Look for hanging branches, tensioned codominant stems, or limbs with deep cracks that could fail with later sun or wind. If any limb is heavy enough to contact a roof or street, treat it as an emergency and call for removal or safe bracing. In urban settings, where mature limbs overhang streets and homes, prioritize access routes that keep people away from the most dangerous hangups. If soil is thin or saturated, monitor root zones for soft spots and any sudden tilting of the trunk, as wet clay soils can amplify stress after a thaw.
Year-to-year spacing and selective thinning before storm season reduce end weight across the canopy on clay soils. Schedule preventive work on hardwoods during dry spells when roots are settling after winter, not in mid-winter ice. Regular checks along the dripline help you spot warning cracks and hollow limbs before they become hazards. For clay soils, avoid heavy pruning during late winter and early spring when moisture movement can destabilize shallow roots; aim for light to moderate directional thinning that preserves natural shape and reduces wind sail. After a storm, plan follow-up pruning promptly to address any new weak points exposed by the event, and consider mulching to improve soil structure and moisture regulation around the root zone.
These tree service companies have been well reviewed for storm damage jobs.
Korte Tree Care
(573) 875-1999 www.kortetreecare.com
3610 Buttonwood Dr Suite 260, Columbia, Missouri
5.0 from 530 reviews
Voss Landscape & Tree Service
(573) 268-3947 www.vosslandscape.com
8501 N Hwy Vv, Columbia, Missouri
4.8 from 82 reviews
On steep, erosion-prone sites with heavy clay soils, these oaks develop dense, heavy canopies that can ache a hillside or trail corridor if not pruned thoughtfully. Weight reduction and clearance planning are the practical goals rather than frequent shaping. Because these oaks grow slowly and store substantial energy in large limbs, cuts should be conservative, targeted, and leave strong branch structure intact. In spring and late summer, anticipate pruning for branch angles and scaffold integrity, not cosmetic thinning. When removing limbs, aim for clean cuts just outside the union collar and avoid flush cuts that invite decay. On clay soils that stay wet after rain, structural pruning is best timed for dry spells to reduce soil compaction from foot traffic and equipment. For these oaks, long-term plan should emphasize removing suppressed watershedding limbs that crowd the interior and threaten the trunk with rubbing, rather than chasing quick visual results.
Honey locust often pushes rapid regrowth from large pruning cuts, creating a dense outer canopy that can shade younger growth and complicate future maintenance. Red maple, while a favorite for quick shade, tends to proliferate dense sprouting if cut aggressively. In Columbia, focus on planned, moderate reductions that maintain natural form and reduce wind-load without inviting aggressive sprouts. Favor selective thinning at the outer canopy to improve light penetration and air movement through the crown, which helps overall tree health on clay soils. Avoid heavy-handed cuts that trigger a flush of brittle, fast-growing shoots. Regular, smaller adjustments every few years are preferable to rare, drastic cuts that leave rough stubs and uneven weight distribution.
These species contribute distinctive character to the planted canopy, yet they behave differently under pruning pressure. Kentucky coffeetree models a robust, architectural profile and responds well to targeted shaping that preserves a strong central scaffold. Leverage selective reductions to control lateral growth and maintain clearance from structures and sidewalks. American basswood tends to develop broad crowns with substantial wood density; it benefits from progressive thinning to keep air flow through the crown and to minimize storm-damage risk on wet, clay soils. For both species, prioritize recognizing natural limb structure and avoid heavy topping-style cuts that weaken joints or alter growth patterns. In practice, plan pruning around growth cycles and seasonal moisture conditions to reduce stress and improve long-term health.
Columbia homeowners are in the service area of University of Missouri extension and state forestry resources that track regional tree health issues in mid-Missouri. That network helps predict when elm decline, oak wilt risk, or locust vascular issues are most active year to year. Rely on local alerts and extension bulletins when planning pruning for aging trees, since disease pressure can shift with seasonal weather patterns and wet springs that favor fungal development.
The city's mix of mature elm, maple, oak, and locust canopy means pruning decisions often need to account for species-specific disease and insect pressure common in central Missouri. Elm disturbances, for example, can be tied to moisture cycling and vector activity, while maples may contend with bacterial or fungal cankers during humid spells. Oaks face bacterial leaf scorch and opportunistic fungi after wounding, and black locust can host scale and borers that exploit stress from pruning or drought. Recognize that heavy clay soils on hillsides retain moisture, creating microclimates where these threats can surge near creek corridors.
Prior to pruning, inspect for signs of decline, cankers, loosened bark, or frass near pruning cuts. If you detect oozing, discoloration, or unusual dieback on a favored limb, pause pruning on that tree and consult extension resources or a certified arborist. For aging trees, stagger pruning so pressure relief occurs gradually, reducing wound susceptibility during peak insect flight periods or fungal spore activity. In dry spells following wet springs, moisture-stressed trees become more vulnerable to disease after any cut. Always sanitize tools between trees to limit pathogen transfer, especially when moving from symptomatic specimens to healthy specimens.
Maintain a routine, site-informed pruning plan that considers tree age, species vulnerability, and the steep, erosion-prone terrain common in Columbia's hillsides. Keep an eye on canopy balance to minimize stress on the root zone, which in turn supports disease resistance. When in doubt, reach out to MU extension updates or state forestry advisories for current mid-Missouri conditions and tailored care recommendations aligned with your yard's clay soils and creek-adjacent microclimates.
Need someone ISA certified? Reviewers noted these companies' credentials
Mid-Country Tree Services
(573) 220-7902 www.mid-countrytreeservices.net
Serving Callaway County
5.0 from 8 reviews
Typical trimming costs in Columbia run about $150 to $1500, with the upper end more likely for large mature hardwoods on sloped lots or near structures. That span recognizes that routine maintenance on a healthy, accessible tree is far less work than a full crown lift or removal from a hillside yard. For a standard mid-size hardwood with a modest canopy, you'll often land toward the lower end, especially when access is straightforward and terrain is level.
Jobs cost more when crews need climbing instead of easy truck access because of hillsides, fenced backyards, creek edges, or saturated clay soils. Sloped sites require rigging and careful footwork, which slows progress and increases time on the job. Heavier clay complicates equipment traction and footing, nudging prices upward even for fundamentals like limb pruning or deadwood removal. Near a structure, special care to avoid damage or required bracing typically adds labor and materials.
Pricing also rises for storm-damaged limbs, utility-adjacent work, and large-canopy oaks or elms that require longer rigging time and more debris handling. Storm damage often means multiple weak points, unpredictable limb behavior, and tighter disposal constraints. Working near power lines or along streets or driveways adds coordination with other utilities and traffic safety measures. Tall oaks and elms demand more rigging gear and longer cleanup, particularly on clay soils where debris can cling to the ground.
If your yard is steep, fenced, or near a creek, expect the estimate to reflect added setup time and careful maneuvering. Ask for a line-item breakdown: access method (truck vs. climber), rigging needs, anticipated debris haul, and disposal charges. For a precise figure, have the arborist assess canopy height, target pruning cuts, and any hazardous limb removal, then compare a couple of local bids to gauge fair pricing within the $150-$1500 range.
For most trees fully on private property in Columbia, pruning generally does not require a permit. This means you can plan routine pruning and cleanup without navigating municipal approvals, provided the work stays on private land and does not involve the public right-of-way. When pruning, keep in mind that heavy trimming on mature hardwoods can affect health and stability, especially on clay soils and steep slopes common in town. Plan pruning timing to align with seasonal patterns and local weather swings.
If the tree is in or near the public right-of-way, homeowners should verify whether it is city-managed before authorizing work. Trees that touch or overhang streets, sidewalks, or utilities may be under city oversight or subject to easements. Do not assume private ownership based on property lines alone. A limb in the right-of-way could require city permission or coordination with utility providers before any pruning or removal.
Questions about public trees, easements, or local forestry oversight are best directed to Columbia's municipal forestry or public works channels. Reach out to the city department that handles street trees and rights-of-way to confirm ownership and any required approvals. Provide a precise location, a photo if possible, and a description of the planned work. Even if a tree seems "yours," clarifying its status helps prevent inadvertent violations and ensures public safety along steep hillsides and creek corridors.
1) Identify the tree's exact location relative to property lines and the right-of-way. 2) Check with the public works or municipal forestry office to confirm ownership and permitting needs. 3) If approval is needed, obtain the official authorization before scheduling any pruning. 4) Keep a record of who approved the work and any requirements or constraints they impose. 5) If in doubt, consult a certified local arborist who is familiar with Columbia's public-tree policies and hillside soil conditions.