Rarely has a video from the National Forestry Office been so viewed. Posted in October on the social networks of the French tree policeman, the sequence was viewed nearly 400,000 times. Its title: “No, ivy does not kill trees”. In eighty-four seconds, the ONF explains to us why this vine known to all should not be uprooted, reminding us that ivy is “neither a parasite nor invasive”. Rather well done, the video sweeps away preconceived ideas to try to convince the snatchers not to touch it anymore. Does she succeed? Obviously not. In the comments, some get carried away, shouting about a new “eco-friendly fad”. 20 minutes took the time to interview specialists to try to establish fact from falsehood and to eradicate stubborn beliefs. Not easy.
It is said to be invasive and useless. Worse, it is said to be responsible for the death of millions of trees. In the garden as in the forest, ivy has a bad reputation. When we question specialists on the issue, we understand that it is nevertheless urgent to restore the honor of this climbing plant. “It is one of the rare climbing plants that has evergreen leaves. In winter it is essential because it has one of the latest blooms. It offers a wonderful refuge for biodiversity and it is a paradise for bees and all insects looking for nectar at this time of year,” assures Benoît Chevallier. The project manager at the National Forestry Office in Brittany never stops praising the merits of ivy, arguing that it can accommodate bats, hide bird nests, provide small black fruits for the heart of winter or even feeding the deer and does when the forests are bare.
“He is still at the scene of the crime”
On the social network delight that Twitter has become, however, we find much more decided reactions. “Ivy is a poison”, or even: “Ivy kills in the long term, that’s a certainty”. These testimonies are often based on a simple observation of a garden or a wood where we saw dead trees covered in ivy. “The problem with ivy is that it’s always at the crime scene. When we see an old dead tree, we accuse the ivy of having smothered it. But just because he’s there doesn’t mean he’s the murderer. It’s more because the trees are sick,” defends the ONF spokesperson. When questioned, the National Horticultural Society of France (SNHF) did not say anything else. “Ivy poses no risk to other plants. He uses his crampons to hold on, but he doesn’t choke anyone. He is the victim of false beliefs which do him a lot of harm,” assures Alice Piacibello, responsible for of the Gardening differently project at the SNHF. It should be noted in particular that the roots of these lianas are fixed only in the ground and not intravenously on the tree.
If ivy is so visible on diseased trees, it is not because it killed them but rather because it was able to capture the light left by branches less rich in leaves. “It is very useful in protecting trees from excess heat or frost because it provides them with cover,” adds Alice Piacibello. At worst, it could be criticized for increasing the wind resistance of certain trees stripped of their leaves in the fall. But in doing this, he also protects all those who are hidden behind the strongest gusts. Forest manager in Ille-et-Vilaine, Olivier Trohel also does not pull out the ivy that climbs the trees of the massifs he exploits. “It would be a huge amount of work. But above all, we realize that trees manage to live in symbiosis. As long as there is no competition, we can leave them. Yes, it can weaken a tree that is at the end of its life or that has been parasitized. But it has a very important place for forest wildlife,” assures the forester.
Among individuals, the image of “a neglected garden”
Independent landscaper in Haute-Savoie, Christophe Gesquière recognizes that ivy “can be interesting for biodiversity”. “In nature, it is complementary to the tree. The birds that nest there even provide fertilizer to the tree with their droppings,” he assures. However, garden professionals do not have the same view when ivy takes over in private homes. “If I tell my customers that they have to keep it, they will laugh in my face! This is precisely why they are calling me. Among individuals, the presence of ivy is often perceived as the image of a neglected garden. »
Then Christophe removes it, often with an ax or chainsaw at the base of the tree. Advice that can also be found on the brand’s well-known website. It is precisely this practice that the ONF would like to see stopped. “We see it too often in the forest. It’s often from people who think they’re doing the right thing. We repeat: ivy does not kill trees, it lives with them,” assures Benoît Chevallier.
And what do we do on the facades?
If the interest of ivy in the wild is no longer in doubt, its presence around houses continues to divide. Should you be worried about seeing your ivy climbing up the rendered gable of the house or creeping into the joints of a pretty stone wall? There, opinions differ. “On the walls, he is capable of breaking everything. It seeps between stones and can move them. At home, there is a wall that will soon fall,” assures Olivier Trohel. The testimony of the logger is far from being an isolated case.
In a post spotted on social networks, Anne-Marie explains this: “On the walls of the house I cut it at the height of the doors so that it does not climb under the roof and I inspect the roots”. But here too, vegetation experts like to nuance the point. “If the wall is good quality and healthy, the ivy will only cling to it. It can even be a good insulator against heat and cold,” maintains Alice Piacibello. However, the argumentation work still promises to take a long time to convince the most doubtful.