Leafless deciduous tree beside a stone garden path on a frosty winter morning

Does the time of year matter for Exeter tree work?

7 min read
Explained
The time of year matters for tree work in Exeter for reasons of tree health, wildlife protection and site conditions. This guide explains how the dormant season, the nesting season, pest timing and storm planning shape when to prune, fell or reduce a tree, and how to build a calendar around them.

Yes, the time of year matters for tree work in Exeter, and it matters for three different reasons: the health of the tree, the protection of wildlife and the practical conditions on site. Pruning at the wrong point in the year can encourage disease, bleeding or weak regrowth. Work during the nesting season can lead to an offence if an active nest is damaged. Heavy rain, frost and wind can stop a crew from working safely at all. This guide explains how the seasons affect the choice of when to prune, fell or reduce a tree, and how to plan the calendar around the constraints that apply.

Dormant season pruning

The dormant season, which runs from late autumn through to late winter, is when many trees are least active. Their sap is not moving strongly, the leaves have fallen and the structure of the crown is easy to read. For many species this is a good time to prune, because the tree is able to respond to the cut with healthy regrowth in the spring and because diseases that spread through fresh wounds are less active. It is also the time when the crown can be assessed for defects, since the branch framework is fully visible.

The dormant season is not suitable for every tree, however. Some species bleed sap heavily when they are cut in late winter or early spring, and the flow can look alarming even though it rarely harms the tree. Birch, maple, walnut and some other species are commonly cited in this context, and an experienced arborist will decide the timing for each tree on its own merits. The point of the dormant season is that it suits many trees well, not that it suits all of them. A survey should identify the species and recommend a season.

Frost can also cause problems. Heavy pruning immediately before a hard frost can leave fresh wounds exposed, and a crew working in icy conditions faces a higher risk of slipping on a climbing line or on a ladder. A good contractor will look at the forecast and reschedule where needed.

Nesting season limits

Spring and summer are when most garden birds build, sit on and feed their young, so this stretch of the year carries the most wildlife risk for tree work. The Wildlife and Countryside Act 1981 makes it an offence intentionally to take, damage or destroy a nest while it is in use or being built, and for the specially protected birds listed in Schedule 1 it also makes it an offence to disturb a bird, intentionally or recklessly, while it is on or near a nest that holds eggs or young. The Act sets no fixed nesting season dates, so the test is whether a nest is in use on the day.

The practical effect is that work during the nesting season needs a check beforehand. A crew that looks at the crown before climbing, notes any nests and stops if it finds one, is working within the law. A crew that cuts first and looks later is taking a risk. The safest approach is to plan necessary work outside the main nesting period where possible, and to schedule any summer work for a date when the surveyor has confirmed that the crown is clear. The compliance service can prepare the check and record what was found.

Oak processionary moth and disease timing

Some pests and diseases are also seasonal, and the season influences both the risk and the surveillance. Oak processionary moth caterpillars are most active in spring and summer, when they move about in processions and feed on oak leaves. Forest Research's record for oak processionary moth urges vigilance during those months and asks people to report suspected findings through TreeAlert. Work on oak trees in those months may therefore need additional care, both to avoid the caterpillar hairs and to keep an eye out for nests.

Ash dieback also has a seasonal dimension. The Forest Research record for ash dieback notes that the change in leaf colour in autumn can be mistaken for disease, which means a survey carried out at that time needs an experienced eye. Scheduling an ash survey in the summer, while the foliage is full and the symptoms are easier to read, gives a clearer result. That timing choice belongs in the planning of the year's work rather than being left to chance.

Storm season planning

The autumn and winter are the windiest months, and many trees in Exeter are most at risk from wind when they are carrying a full crown in autumn or when they are waterlogged after heavy rain. Storm season planning means inspecting trees before the worst weather arrives, dealing with weak limbs and dead wood while the crew is still working to a planned programme and avoiding a rush of emergency jobs after a named storm. The Met Office's UK weather warnings show the warnings issued for the region and are a useful reference when deciding when a crew should not work.

An autumn inspection is particularly valuable for trees over a path, a car park or a building. A defect that is spotted in October can be dealt with in a planned visit, while the same defect discovered after a gale is an emergency with higher costs and greater risk. The maintenance service is designed for this kind of programme, with inspections timed around the seasons and work scheduled when the tree and the site allow.

Summer work and heat

Summer offers long daylight hours and generally drier weather, which suits some jobs well. It also brings the nesting season, the peak of leaf growth and the risk of heat stress for the crew. A tree that is heavily reduced in high summer can suffer sunscald on the exposed bark, and a crew working in the heat is more likely to tire on a climbing line. Summer work is most suitable for light trimming, for checks that do not involve heavy cutting and for removal jobs where the nesting check has been completed.

Trees that have been heavily pruned in summer should be checked in the following weeks for signs of stress. Watering during dry spells helps, as described in the guide on caring for a pruned tree in Exeter, and a short inspection in the autumn will show how the tree has responded.

Building the calendar

A sensible calendar for an Exeter garden or site starts with a survey in the summer, when the foliage is full and the health of the tree can be judged. The survey then sets out which work is needed and when. Necessary work is scheduled in the dormant season where the species allows, with a nesting check on the day. Storm season inspections are planned for the autumn, and a follow-up visit is booked for the following year. Emergency work is always possible, but the aim is to reduce the number of emergencies by planning ahead.

Where a job needs a council consent, the timetable is set by the consent process, and the season may need to fit around the decision date. Where a job sits alongside construction, the calendar should follow the protection requirements in protecting trees during building work in Exeter. Where the tree is in a conservation area and not protected by an order, the six-week notice period under the Town and Country Planning Act 1990 runs before the work can begin, so the calendar should start the notice early enough to allow the work in the planned season.

Asking the right questions

An owner planning a job in Exeter should ask the contractor which season it recommends and why, what checks will be made for nesting birds and pests, and how the programme copes with bad weather. A quote request that gives the address, the trees involved and any preferred dates allows the contractor to match the season to the species and to the site. The answer will not be the same for every tree, and a contractor who says that every job must be done in the same month is not thinking about the tree in front of it.