Can copper nails kill a tree? There is a lot of debate online, especially on gardening forums as to whether a few copper nails into the trunk of a tree can restrict growth and eventually kill off the willow or birch you are trying to fell.
But are copper nails really that effective? Below are some experts opinions, but firstly we need to understand what copper nails are, what they are traditionally used for and whether or not they are the best weapon of choice in the war against unwanted trees and bushes.
What are copper nails and what are their traditional uses?
Copper nails are typically used for roofing projects – securing tiles and slates. Copper nails are particularly popular as they have less unwanted features which galvanised nails, the cheaper alternative, sometimes have.
For example, it is against building regulations to use galvanised nails on a slate roof. The galvanised treatment of these nails also makes them more susceptible to pollution damage, damage near coastal regions and even lose their protection whilst being hammered into the place. The result is a faster corrosion which can lead to slates and tiles slipping off the roof.
Copper nails on the other hand are a lot more durable a d weather resistant, and they are also easier to replace when a broken slate needs repairing.
Can copper nails really kill a tree?
As mentioned in the opening paragraph, there are many varying reports online as to the success of using copper nails to kill trees. The general advice is to hammer a handful of nails, the amount depending on the size of the tree, into the base of the plant – but this may not be the end of the story.
Nicholas Lepp, a Professor of Plant Sciences at Liverpool John Moores University said that it is not the copper nail itself that kills the tree, but the movement of copper around the trunk and cells.
He said: “In order to kill a tree, a toxin must interfere with cell division in the regions from which a tree grows – root and shoot tips. Inhibition of a vital process such as photosynthesis will have a similar deleterious effect.
“Implanting a piece of copper in a tree trunk will only affect such vital processes of the copper is transported from the implant to the roots and shoots.”
The science is that the copper extract from the nail has to be deposited straight into the vital veins of the tree to have any damaging effect, either the xylem which is the inner bulk of the tree that transports water from the roots to leaves, or through the bark which helps the photosynthesis process. Bark however is extremely quick to repair itself and so doesn't give time enough for the copper in the nail to dissolve and enter the vital inner systems of the tree and cause damage.
So aside from looking like the tree is under attack by hammering dozens of nails into the bark, copper nails are actually very unlikely to kill off a healthy tree at least as it has more powers to repair itself, but may work on an old plant or tree stump.
Alternative tree killing solutions
Whilst many reading this blog post will want to kill a tree discreetly, perhaps as a neighbour refuses to chop it down and it is blocking sunlight, discreet copper nails may be the answer.
There are other more discreet ways to kill a tree than starting the chainsaw however. Firstly, you could try changing the soil around the tree, such as its PH value or adding mulch and in doing so compacting the formerly loose soil. You can also try either starving the tree of water or drowning it in a deluge every day, or by burning the roots using a fast release fertiliser.
Written by Arthur Hamilton, a regular guest blogger on all things gardening and DIY.