Help the tree

In February 2021 a development project put the Imperial Cedar at risk. The campaign that followed saved it, and there is no petition running today. But the tree is not out of danger for that: the ground around it has been sealed, and what it suffers from now is drought.

What happened in 2021

Early in 2021, a building project was considered for the plot where the tree stands. The argument put forward was safety: the cedar was said to be diseased, and therefore dangerous. A counter-assessment and a citizens' campaign came together quickly.

Thousands of children drew the tree to ask for its protection. A petition was launched on change.org against the abusive felling of remarkable trees. The ARCBM association was formed. In 2021 the local authority listened, and the Imperial Cedar was preserved.

The rest of this page explains what is happening beneath the surface, then how to help.

A tree does not die from the trunk. It dies from the ground.

The Imperial Cedar has stood for more than two centuries. What threatens it today is neither a storm nor a disease, but a few centimetres of impermeable surface laid over its roots.

Roots breathe, and they spread far

Contrary to a widespread image, the roots of a large tree do not plunge deep like a mirror of its crown. They form a wide, shallow plate: the fine absorbing roots, those that actually take up water and minerals, are concentrated in the first thirty to sixty centimetres of soil, and commonly extend well beyond the outline of the branches.

These roots are living tissue. They consume oxygen and release carbon dioxide, exactly as leaves do. That exchange happens through the pores of the soil. A soil that can no longer breathe is a soil in which roots suffocate.

What an impermeable surface actually does

Sealing the ground around a tree acts on three fronts at once, and none of them is visible from the street.

Rainwater no longer reaches the roots. It runs off towards the drains instead of soaking in. A mature cedar transpires hundreds of litres a day in summer; if the water it draws on is diverted, it lives on a reserve that no longer refills.

Gas exchange stops. Deprived of oxygen, the fine roots die back. The tree loses precisely the organs that feed it, while keeping the whole mass it has to sustain.

The soil life collapses. A cedar lives in symbiosis with soil fungi, the mycorrhizae, which extend its absorbing surface many times over. These fungi need air, moisture and organic matter. Under an impermeable surface they disappear, and with them a large part of the tree’s ability to feed itself.

The trap: a decline that arrives years later

This is the point that matters most, and the one most often missed. A mature tree carries considerable reserves. It can absorb an attack on its roots for ten or twenty years before the symptoms show in its crown: thinning foliage, dieback at the tips, branches drying out.

A circle then closes. The ground is sealed, the tree slowly declines, and years later its condition is invoked to declare it sick, then dangerous, then to be felled. Cause and verdict are separated by so much time that the link is no longer made. Naming that sequence is the first act of protection.

What would actually help

The measures are known, modest and reversible. None of them requires felling anything.

• Open the ground back up. Removing the impermeable surface over the root zone, or replacing it with a draining material — stabilised gravel, permeable paving, open-jointed slabs — restores both infiltration and air.
• Define a root protection zone. A marked area, at least matching the spread of the crown, where nothing is dug, stored, parked or compacted. Soil compaction by vehicles is as damaging as concrete.
• Mulch rather than pave. A layer of wood chips or leaf litter holds moisture, feeds the soil life and protects the surface roots.
• Have an independent arborist assess it. A diagnosis carried out by a tree specialist, distinct from the party planning any works, and made public.

None of this is theoretical. A few kilometres from Meudon, in the same département, another cedar of Lebanon shows what these measures look like once applied.

Meudon · the Imperial Cedar

Le Plessis-Robinson · same species

The two settings are comparable: both trees stand in town, beside a road, surrounded by buildings. What separates them is what covers their roots. The result can be read in the crowns — dense and tiered right down to the low branches at Le Plessis-Robinson, thinning at Meudon.

A plaque, and what lies behind it

Protecting a tree is not only a matter of soil. It is also a matter of status. A tree that carries a name, a plaque and a recognised history is far harder to fell than an anonymous tree on a plot of land.

Since 2000 the French association A.R.B.R.E.S. has awarded a “Arbre Remarquable de France” label, held by around a thousand trees. It comes with a plaque and a public commitment by the owner to look after the tree. The label is honorary rather than legal: it creates no obligation. Its strength lies elsewhere — it makes the tree visible, documented, and attached to a community that watches over it. The Imperial Cedar, planted under the Empire and linked to two centuries of documented history, has every characteristic such a label recognises.

A stronger step exists. Under the law of 2 May 1930, now part of the environment code, the State can classify a tree as a natural monument. That classification is a genuine legal protection, and a number of trees in France hold it. It is demanding to obtain — which is precisely why documenting this cedar’s history, gathering its photographs and its testimonies, is not a sentimental exercise. It builds the case file.

A local authority can also protect a tree through its town planning document, by identifying it as a landscape feature to be preserved. That path is often the quickest, and it rests on a municipal decision — therefore on public attention.

The precedent is worth weighing. Le Plessis-Robinson did not wait for a label or a State classification: the council laid a plaque, marked out a generous root area and mulched it. Nothing in that requires a procedure — only a decision.

Three ways to help

There is no petition left to sign: the one launched in 2021 aimed to prevent the felling, and it achieved that. What matters now comes down to three things.

Visiting the Imperial Cedar

The tree stands at 11 rue de la République, 92190 Meudon, 6.6 km from the Eiffel Tower. It is visible from the street, freely and at no cost. Sunrise and nightfall give the finest light, with the silhouette of Paris behind it.