Choosing a tree surgeon, and what drives the cost

What to ask before anyone starts

Tree work is one of the more hazardous trades, carried out at height, with chainsaws, usually within a few metres of a house. The questions below are reasonable to ask anyone, and a competent contractor will expect them. Ask to see documents rather than take a verbal answer, and check the dates on them, since cover and qualifications both expire.

• Do you hold public liability insurance, and may I see a current certificate?
• Who will be on site, and what chainsaw and aerial rescue qualifications do they hold?
• Is the quote in writing, with the work described tree by tree in proper terms, for example "crown reduction by two metres to suitable growth points" rather than "cut back"?
• What happens to the waste, and are you registered with the Environment Agency as a waste carrier?
• Have you checked whether the tree has a Tree Preservation Order or sits in a conservation area?
• Does the price include grinding the stump, or is the stump being left?
• Will the site be left clear, including chippings and sawdust?

Warning signs worth acting on

Most problems announce themselves before the work starts. The common pattern is someone knocking at the door, often after a storm, offering to deal with a tree there and then at a price that sounds too good to refuse. The pressure to decide quickly is the point. A tree that genuinely needs attention will still need it tomorrow, and anything truly dangerous should be cordoned off rather than rushed.

Treat the following as reasons to stop and get another quote: no written quotation, no company details on the paperwork, cash only, a large payment demanded up front, an unwillingness to show insurance, and no mention of the tree’s protected status. An offer to "top" a tree is a particular warning, because it signals a contractor who either does not know or does not care that the practice damages the tree.

• Door-knocking or cold calling, especially after bad weather
• A verbal price only, with no written scope of work
• Cash only, or a substantial deposit before any work
• No public liability certificate offered when asked
• An offer to top the tree
• No question asked about Tree Preservation Orders or conservation areas
• Vagueness about where the waste is going

What drives the cost of a removal

Size is the obvious factor, but it is volume rather than height that matters, and volume rises sharply with diameter. A dense, heavy hardwood takes longer to cut and produces far more material to move than a soft, light-timbered tree of the same height. Species also affects how the timber behaves on the saw and how it can be rigged, which feeds into the time on site.

Access usually accounts for the difference between two quotes on an identical tree. A tree that can be felled into open space, with a chipper parked alongside and a short carry to the vehicle, is a straightforward day. The same tree in a back garden reached only through a narrow side gate, where every section must be lowered on ropes and carried by hand to the road, is a much longer one.

Then come the constraints: proximity to a building, a conservatory, a boundary or overhead cables; whether the work can be climbed or needs a mobile elevating work platform, which may also need a permit or a road closure; the volume of material to dispose of; and whether a council application is required first. Any of these changes the shape of a job, which is why written quotes for the same tree vary.

What drives the cost of a prune

Pruning is priced on much the same basis, with time on site doing most of the work. A light crown lift over a driveway is a short visit. A full reduction on a mature tree means a climber working methodically around the whole canopy, making a large number of considered cuts, and the arisings still have to come down, be chipped and be taken away.

Two things tend to surprise people. The first is that the brash from a reduction can be a greater volume than from a small removal, so disposal is a real component of the price. The second is that condition matters: a tree with decay, deadwood or an awkward fork needs a more cautious approach aloft, and the rigging that makes that safe takes time to set up.

Getting quotes you can actually compare

Ask two or three contractors to look at the same tree and put the work in writing. Comparison only works if the scope matches, so check each quote specifies the same operations, says whether the stump is included, states what happens to the timber and chippings, and confirms who is responsible for any council application. A quote reading "remove tree" and one reading "sectional dismantle, grind stump, all arisings removed" are not the same day.

Be wary of comparing against figures found online. Published averages lump together jobs with nothing in common, from a small garden tree with a drive alongside to a mature specimen over a roof. A site visit is the only basis for a real price, and we quote in writing after seeing the tree so that the scope is clear before anything is agreed.

Should you remove the stump or leave it?

Grinding is worth it where the ground has a job to do. If the area will be turfed, paved, built on or replanted, the stump and the main root plate need to come out, and grinding takes the stump below ground level so the ground can be made good. A stump in the middle of a lawn is a mowing obstacle and a trip hazard, and the ground around it settles unevenly as the roots decay.

Regrowth is the other practical argument. Many broadleaves, notably willow, poplar, sycamore, lime and cherry, send up suckers and shoots from a cut stump and from roots spreading well beyond it, which can mean years of cutting back. Grinding the stump and the larger surface roots stops that at source. A decaying stump can also support honey fungus, which matters if you plan to plant susceptible shrubs nearby.

Leaving it is perfectly reasonable in the right place. At the back of a border or in a wild corner, a stump is good habitat for insects, fungi and nesting birds, and it costs nothing. If you intend to replant on the same spot, bear in mind that grinding leaves a pit of woodchip and soil which needs the chip removing and replacing with topsoil first.