Action sheet — Before the fire
Thinning and pruning trees: breaking the fire’s chain of transmission
A fire climbs from the ground to the treetops via the lower branches, then jumps from canopy to canopy. Three metres between the tree crowns, two metres of bare trunk: these two figures transform a garden that acts as a fire trap into one that slows the fire — without having to fell your beautiful trees.
Key points
- Trees spaced at least 2–3 metres apart — and from any building.
- Trunks pruned to a height of 2 metres (50 per cent of the height for young trees).
- No branches above the roof or within 3 metres of a façade.
- Beneath the trees: neither undergrowth nor shrubs — the middle layer is the fire’s fuel.
Equipment: pruning saw / extension pole · heavy-duty secateurs · safety ladder · garden shredder or disposal at a recycling centre
Why it’s important
A fire spreading across the grass can be stopped; once it reaches the treetops, it can no longer be extinguished by ground-based methods. The transition from one to the other occurs through the vertical continuity : grasses → shrubs → lower branches → crown. Then the horizontal continuity spreads from treetop to treetop. Removing these two pathways is exactly what the OLD regulations require — and it’s common-sense forestry that makes your trees healthier and more attractive. The full framework: do my brush-clearing.
How to do it, step by step
Map out your topics
Walk around the property: mark any trees whose crowns are touching, those that overhang the roof, and any dead or dying trees (these should be removed as a priority — a dead tree is a fire hazard).
Prune the trunks to a height of 2 m
Cut back the lower branches flush with the growth ring (not flush with the trunk, leaving no stump), doing so gradually — never removing more than a third of the living crown in any one year.
Space out the wreaths
Where two trees are touching: prune the less attractive one, or remove every other tree in dense copses. Aim for a gap of 2–3 metres between the crowns (as specified in local by-laws).
Clear the frame
No branches above the roof or within 3 metres of the façades — absolute priority on the side facing the prevailing wind and on the side with natural vegetation.
Clean the floor below
Beneath each tree that is being retained: no shrubs, raked litter, short grass. This is what ensures that a ground fire PASSES beneath the tree without spreading up it.
Clear away the crop residues
Shredding (for mulching in distant flowerbeds) or taking to the recycling centre — burning is prohibited: the relevant information sheet.
The mistakes that ruin everything
- Topping trees (uncontrolled ‘pollarding’): guaranteed to produce dense, highly flammable suckers the following year.
- Prune during the nesting season (mid-March to late July) or whilst the sap is flowing.
- Clearing everything away out of overzealousness: a light cover actually helps to limit the regrowth of undergrowth.
- Leave the piles of branches to dry where they are ‘for the time being’ — perfect kindling.
The tip that makes all the difference
A quick visual check: crouch down and look under your trees. If you can see the landscape through clear trunks, you’re fine; if you see a wall of green from the ground to the treetops, the fire ladder is in place.
Frequently Asked Questions
The risk changes every day. So do your reflexes.
Check the fire alert status for your department, keep track of current fires and report a fire via the Feux de Forêt mobile app.