Why guarantees matter when hiring an arborist
Tree work can look straightforward from the road, but in practice it involves risk, specialist equipment, and judgement calls about tree health, property protection, and public safety. That is why it is worth asking any arborist not just what they will do, but what they will stand behind if something goes wrong.
A strong guarantee helps you judge whether the arborist is confident in their work. More importantly, it gives you a clear path if a tree is pruned badly, a stump grind fails, a hedge dies after planting, or a contractor damages your section and does not put it right.
For New Zealand homeowners, the key protections usually fall into three buckets:
- the arborist’s own workmanship guarantee - any product or plant warranty from a supplier or manufacturer - your rights under the Consumer Guarantees Act 1993 (CGA)
What a workmanship guarantee should cover
A workmanship guarantee is the arborist’s promise about the quality of their labour. It is separate from any warranty on materials or plants.
For arborist work, a workmanship guarantee is most useful when it is written and specific. It should say exactly what is covered, for how long, and what the arborist will do if the work is not up to standard.
Typical workmanship items to ask about include:
- pruning carried out to the agreed standard and method - removal of dead, unsafe, or unwanted branches as specified - stump grinding to the agreed depth - clean-up and removal of green waste - repair of minor damage caused during the job, where agreed - re-work if the wrong tree is cut, or the pruning is clearly outside the quoted scope
A good workmanship guarantee should also make clear what is not covered. For example, an arborist should not be responsible for:
- natural tree decline caused by drought, disease, storm damage, or poor pre-existing tree health - regrowth or sprouting that is normal after pruning - trees that fail because they were already structurally unsound - issues caused by another contractor, the homeowner, or a storm after the job is complete
If the arborist is planting new trees or shrubs, ask whether they guarantee the planting method, staking, mulching, and initial establishment period. In New Zealand conditions, that matters because summer heat, water restrictions, coastal winds, and dry autumns can affect establishment even when the planting itself is done correctly.
Product warranties: when the arborist supplies materials
Many arborists mainly provide labour, but some also supply mulch, fertiliser, stakes, ties, irrigation components, tree protection products, or even the plants themselves.
A product warranty is different from a workmanship guarantee. It usually comes from the manufacturer or supplier, not the arborist. If a supplied item fails, the warranty may allow repair, replacement, or refund depending on the product and circumstances.
Examples include:
- tree stakes and ties supplied as part of a planting job - fertiliser or soil amendments - irrigation parts for newly planted trees - replacement trees or shrubs - anti-desiccant sprays or protective wraps
Ask for the brand and product name in the quote or invoice, plus the warranty terms if relevant. If an arborist tells you a plant is “guaranteed”, find out whether that means:
- the plant itself is covered by a supplier warranty - the arborist will replace it once if it dies within a set period - the guarantee only applies if you follow a watering and care programme
That last point is important. In many planting jobs, a guarantee may depend on you watering correctly, keeping mulch in place, and not over-pruning or damaging the plant afterwards.
The Consumer Guarantees Act and arborist services
The Consumer Guarantees Act 1993 gives New Zealand consumers automatic rights when they buy services from a business for personal, domestic, or household use. You do not need a special warranty for these rights to apply.
For arborist services, the most relevant CGA guarantees are that the service must be:
- carried out with reasonable care and skill - fit for the purpose you told the arborist about - completed within a reasonable time, if no time is agreed - supplied for a reasonable price, if no price is agreed
If a homeowner clearly asks for a tree to be made safe near a driveway, or a limb to be removed without damaging a fence, the service should be fit for that purpose. If the arborist takes the job but uses poor technique, leaves dangerous hanging branches, or causes avoidable damage through carelessness, the CGA may help.
It is worth noting that the CGA applies to services and to goods separately. So if an arborist supplies plants or materials, those goods must also be of acceptable quality and match their description.
However, the CGA does not cover every situation. It will not make an arborist responsible for outcomes caused by things outside their control, such as severe weather, hidden disease, or a tree’s natural biology.
What a good arborist quote should say about guarantees
The best time to sort out guarantees is before the job starts, not after there is a problem. Get at least two or three written quotes so you can compare what is included, not just the price.
A solid arborist quote should cover:
| Item | What to look for | |---|---| | Scope of work | Exactly which trees, branches, stumps, or hedges are included | | Standard of work | What method or outcome is being promised | | Guarantee period | How long workmanship is covered | | Exclusions | Weather, disease, pre-existing defects, irrigation failures, and other limits | | Materials | Brand names, grade, quantity, and whether products are covered by supplier warranties | | Site conditions | Access issues, power lines, fences, gardens, and driveway protection | | Clean-up | Whether green waste, sawdust, and stumps are removed or left on site | | Remedial work | What happens if there is a defect or accidental damage |
If the quote is vague, ask for clarification in writing. Words like “trim back as needed” or “make safe” can lead to disputes if the result is not what you expected.
What is reasonable to expect from an arborist guarantee?
A good guarantee is fair to both sides. It should protect the homeowner from poor workmanship, but it should not promise the impossible.
Reasonable expectations often include:
- the arborist will return to fix clear defects in workmanship - accidental damage caused by the contractor will be repaired or compensated, subject to the contract and insurance - supplied materials will be as described and installed correctly - the contractor will be contactable if something is not right
Unrealistic promises often include:
- guaranteeing a tree will never fail after pruning - guaranteeing a newly planted tree will survive regardless of watering or weather - promising no regrowth after hedging or pruning - offering no written terms at all but expecting you to trust a verbal promise
Seasonal conditions in New Zealand should also be considered. For example, a planting guarantee may be harder to enforce if planting occurred in the heat of summer during a dry spell, especially if there were water restrictions or the site has free-draining soil. A competent arborist should explain those risks up front and adjust the plan, timing, or aftercare accordingly.
If the arborist gets it wrong: your practical recourse
If you think the work is faulty, act promptly and keep good records. Most disputes are easier to resolve when you document the problem clearly.
Start with these steps:
1. **Take dated photos or video** of the issue from several angles. 2. **Check the quote and invoice** to confirm what was agreed. 3. **Contact the arborist in writing** and explain the defect. 4. **Ask for a remedy** — usually a return visit, repair, replacement, or partial refund. 5. **Set a reasonable deadline** for response and action.
If the arborist is a member of a trade association or has their own complaints process, use that as well.
Under the CGA, if the problem is minor and can be fixed, the trader may be able to put it right. If the problem is substantial, or if the service fails to meet the CGA standard and cannot be remedied in a reasonable way, you may be entitled to a reduction in price or to recover costs of corrective work.
If there is property damage, check whether the arborist has public liability insurance and ask for their insurance details. Insurance does not replace CGA rights, but it can be important for practical recovery.
If the contractor refuses to fix the issue, you can consider:
- getting a second opinion from another qualified arborist - asking for a written report on the workmanship problem - making a formal complaint to the company - using the Disputes Tribunal for lower-value disputes - seeking legal advice if the damage or cost is significant
How to protect yourself before you hire
The simplest way to avoid warranty problems is to choose the right arborist and pin down the details before work starts.
Look for:
- a written quote, not just a phone estimate - proof of relevant experience and qualifications - appropriate insurance - clear communication about risks and limitations - a record of past work or references - willingness to explain how the guarantee works
Also make sure the arborist understands any special site issues, such as:
- trees near power lines - access over neighbouring property - roots affecting retaining walls, driveways, or drainage - boundary trees and neighbour permissions - council rules, protected trees, or overlays in your district plan
Tree work itself usually does not need a building consent, but some situations can trigger other approvals. For example, if the work is part of a larger project affecting structures, retaining walls, services, or protected vegetation, you may need to check with your local council first. If there are power lines involved, only appropriately trained and authorised workers should deal with them.
Bottom line
A trustworthy arborist should offer more than a verbal promise. At minimum, you want a clear workmanship guarantee, clarity on any product or plant warranties, and an understanding of your rights under the Consumer Guarantees Act.
The best protection is simple: get several written quotes, ask what is guaranteed and what is excluded, check credentials and insurance, and keep records if anything goes wrong. That way, you are far more likely to end up with safe, tidy, and lasting tree work — and a clear path forward if the result is not what you paid for.