Have you ever heard of paulownia tomentosa, the so-called “imperial tree”? If you are passionate about gardening and follow Greenme news, probably yes. We are talking about a majestic tree, native to China and Korea, often presented as the panacea against climate change: it grows very fast, absorbs quantities of carbon ten times higher than those of a common tree and sports spectacular flowers, which seem to have come out of a Japanese painting.
Perfect, right? Yet, as often happens with miracles, there is a “but”. Or, rather, there are several.
An invasive tree… in every sense
When talking about paulownia, the word “invasive” is not an exaggeration. In countries such as the United States, Switzerland and New Zealand, this tree has already been classified as an invasive exotic species. What does it mean? Which grows so fast and with such aggression that it can disturb local ecosystems. The native flora finds itself competing with a tree that seems to have pressed the accelerator, and often succumbs. And that’s not all: wildlife tends to desert the areas colonized by paulownia because they simply don’t recognize it as “home”. It’s as if a new neighbor arrived, built a giant mansion in a couple of weeks and took over the entire garden. Not exactly the best for those who lived there before.
But be careful: not all paulownias are the same. Commercial hybrids, used for agricultural or decorative purposes, are often less invasive. Of course, “less invasive” does not mean invasive at all. Planting it without thinking twice could still lead to the disappearance of other local species.
Robust roots and insatiable thirst
Now imagine this scenario: You decide to plant a paulownia in your backyard because, well, it’s the tree of the moment. It grows quickly, it’s beautiful, it absorbs carbon… what problem could there be? The problem is its roots. They grow quickly and without any consideration for what they find along their path. Water pipes? They break them. Foundation of a house? They put them at risk. Small plants that you have lovingly planted nearby? They suffocate them.
And then there’s the water. A young paulownia can consume up to 100 liters of water per week. You understood correctly: one hundred litres. If you live in an area prone to drought, this insatiable thirst could become a serious problem, especially for underground water supplies. The tree will draw mercilessly, leaving little for nearby plants and further lowering water availability during the most critical periods.
Not as strong as it seems
Paulownia is often touted as a sturdy tree, but this is a partial truth. Yes, it grows quickly and resists the most diverse climates quite well, but it is vulnerable to various infections and parasites. Crown rot, for example, is a fungal disease that can be fatal to the tree. It’s not really a small matter.
We then add attacks by caterpillars, cockroaches and beetles, such as the infamous Asian long-horned beetle, which might seem like a mythological creature but is, in reality, an insect capable of devastating the structure of the tree. These parasites, in many cases, require expensive and often chemical treatments to eradicate.
So what? Is it really worth it?
Don’t get me wrong: Paulownia tomentosa remains a fascinating tree. The natural and extraordinary ability to absorb carbon is truly impressive, and can play an important role in environmental protection. Not to mention the beauty of the flowers, which transform the landscape into a pink and purple spectacle during flowering, and the quality of the wood, light and resistant, another point in its favor, especially for building and artisan use.
But, as often happens, there is no magic solution to environmental problems. Planting a paulownia requires awareness: it is essential to evaluate the context, the local ecosystem and the management of water resources. A tree that absorbs carbon but destroys everything around it could do more harm than good in the long run.
In the end, it’s up to us to decide: paulownia is a tree with great potential, but also with great responsibilities. If you decide to plant it, do so judiciously and with a pinch of caution.
