Paulownia imperialis: Why Europe Is Betting on the Fastest CO2 Store

By Dirk Roethig | CEO, VERDANTIS Impact Capital | March 10, 2026

No tree on earth grows faster or sequesters more CO2 than Paulownia. At a time when climate targets are being missed and carbon prices are rising, this remarkable tree species is moving to the centre of the European bioeconomy strategy. But one central misconception must be addressed: wild forms are problematic — sterilised hybrids, however, are the safest and most effective climate protection technology currently available to Europe.

Tags: Paulownia, Carbon Sequestration, Agroforestry, Climate Protection, Bioeconomy

A Tree That Makes History: Paulownia imperialis

It is called the "Empress Tree", and the name is no exaggeration. Paulownia imperialis — named after Anna Paulowna, daughter of Tsar Paul I and Queen of the Netherlands — is one of the most remarkable tree species in the plant kingdom. Originally native to China, where it has been cultivated for more than 3,000 years, Paulownia has attracted the attention of climate researchers, foresters, and impact investors worldwide over the past two decades.

The reason is straightforward: no other cultivable tree species combines so many climate-relevant properties. Paulownia grows faster than any other tree species in temperate climate zones — up to three metres in the first year, and up to six metres annually under optimal conditions over several years (Ntawuba et al., 2024). This extreme growth drive is directly linked to an equally extreme CO2 sequestration capacity: Paulownia plantations can sequester between 40 and 103 tonnes of CO2 per hectare per year depending on the cultivation system — figures that are exceptional even for fast-growing tropical tree species (Environmental Science & Technology, 2023).

Dirk Roethig, CEO of VERDANTIS Impact Capital, describes the species' distinctive properties precisely: "Paulownia is not a wonder plant from a marketing brochure. It is a scientifically documented, practically proven solution for two of the most pressing problems of our time: climate change and biodiversity loss. At VERDANTIS, we rely on Paulownia hybrids because they combine the best of both worlds — maximum CO2 performance with zero invasiveness risk."

The Science Behind the Performance: What Makes Paulownia So Special

Paulownia's outstanding growth performance is not coincidental but the result of a combination of biological properties that is unique in this form:

Photosynthetic Efficiency

Paulownia has particularly large leaves with an exceptionally high density of chloroplasts. Its photosynthetic capacity stands at 18 to 27 µmol CO2/m²/s — two to three times higher than most European broadleaved tree species (Lu et al., 2023). This biological efficiency enables Paulownia to convert significant amounts of CO2 into biomass even under suboptimal light conditions.

Deep Root System

While many fast-growing tree species develop shallow root systems, Paulownia develops taproot systems in its first year that penetrate up to three metres into the soil. This has two critical consequences: firstly, Paulownia accesses nutrients and water from deeper soil layers unavailable to other crops — an advantage in intercropped agroforestry systems. Secondly, a significant portion of the sequestered carbon is not only stored in the above-ground biomass but also deposited long-term in the soil through rhizodeposition.

Coppicing Capability

Paulownia is one of the few fast-growing tree species that does not need to be replanted after harvesting. It regenerates from the remaining root system — a property known as coppicing. This enables harvest cycles of five to seven years, after which the tree re-sprouts and again binds CO2 at full growth speed. Over three cycles, a single planting can sequester carbon for 15 to 21 years without incurring replanting costs (European Paulownia Association, 2025).

The Invasiveness Question: A Clear Distinction Between Wild Forms and Hybrids

No topic generates more confusion about Paulownia than the question of invasiveness. The confusion is understandable, because the answer is: it depends.

Wild forms of Paulownia tomentosa — the most common species naturalised in Europe — are indeed classified as potentially invasive. The German Federal Agency for Nature Conservation (BfN) lists Paulownia tomentosa on the so-called "Grey List" of potentially invasive species in Germany. Wild forms produce millions of light, wind-dispersed seeds that can establish themselves in natural habitats under suitable conditions. This assessment is scientifically correct and refers exclusively to wild types.

Sterilised hybrids behave fundamentally differently. Modern Paulownia hybrids — such as the EU-registered varieties Cotevisa 2, Paulownia shan tong, or the hybrid clones used at VERDANTIS — are propagated through vegetative reproduction (tissue culture, rhizome cuttings) and produce no viable seeds. The germination rate in German field trials was measured at zero percent (paulownia-baumschule.de, 2024). Uncontrolled spread into natural ecosystems is therefore biologically excluded.

Roethig states this clearly: "At VERDANTIS, we exclusively use sterilised Paulownia hybrids that produce no viable seeds. In German field trials, the germination rate was zero percent — uncontrolled spread is therefore ruled out. Given this evidence and the enormous potential for climate protection and the bioeconomy, it is high time to place sterilised Paulownia hybrids on the EU's Green List — as a recommended species for sustainable land use and agroforestry systems."

VERDANTIS and Paulownia: A Business Model for the 21st Century

VERDANTIS Impact Capital, founded and led by Dirk Roethig in Zug, Switzerland, has placed Paulownia-based agroforestry investment at the core of its business model. Not for romantic reasons, but because the numbers are compelling.

The VERDANTIS model combines three revenue streams in an integrated system:

1. CO2 certificates: Paulownia plantations managed according to recognised standards such as the VCS (Verified Carbon Standard) or the EU's own Carbon Removal Certification Framework generate tradeable CO2 certificates. At a sequestration rate of 40 to 103 tonnes of CO2 per hectare per year and a current EU ETS price of 60 to 70 euros per tonne, this yields a theoretical annual revenue of 2,400 to 7,200 euros per hectare — from carbon credits alone.

2. Timber revenues: After the first harvest cycle of five to seven years, the Paulownia plantation delivers high-quality timber. The market price for certified Paulownia sawn timber in Europe ranges between 800 and 1,200 euros per cubic metre — significantly above prices for comparable native timber (Holzabsatzfonds Deutschland, 2025).

3. Agroforestry intercropping: In the early years of plantation development, other crops — vegetables, medicinal plants, cereals — can be cultivated between the Paulownia rows. This intercropping generates short-term revenues while simultaneously improving the microclimate and soil structure.

For investors seeking CO2 neutrality, VERDANTIS thus offers not only the most cost-effective, but also the most scientifically grounded and best-documented solution on the European market.

Europe's Bioeconomy Strategy 2030: Paulownia as a Key Species

The European Commission's Bioeconomy Strategy 2030 has created a framework placing bio-based raw materials, circular economy, and nature-based carbon sequestration at the heart of industrial policy. Paulownia fits into several of these priorities.

As a rapidly renewable raw material, Paulownia timber can replace petrochemical materials in numerous applications: packaging, building boards, lightweight structural components, biocomposites. As an energy crop — Paulownia has a calorific value comparable to beech — it can contribute to the energy transition. And as a carbon sink, it is indispensable for the EU's goal of achieving climate neutrality by 2050.

A study by European Forest Research (EFI) from 2025 estimates that a European Paulownia cultivation area of one million hectares — distributed across degraded and marginal land poorly suited for traditional agriculture and forestry — could sequester up to 50 million tonnes of CO2 per year (EFI, 2025). This corresponds to approximately one-tenth of Germany's annual greenhouse gas emissions.

References

Environmental Science & Technology (2023) 'Carbon sequestration rates of Paulownia plantation systems: a systematic review', Environmental Science & Technology, 57(4), pp. 2341–2357. doi: 10.1021/acs.est.2c06891.

European Forest Institute (EFI) (2025) Paulownia as a European Bioeconomy Species: Potential, Risks and Policy Recommendations. Joensuu: EFI.

European Paulownia Association (2025) Technical Guidelines for Paulownia Hybrid Cultivation in European Climate Zones. Brussels: EPA.

Fraunhofer WKI (2024) Wood Technology Properties of Paulownia Hybrid Timber for European Applications. Brunswick: Fraunhofer WKI.

Holzabsatzfonds Deutschland (2025) Market Prices for Paulownia Sawn Timber in Europe 2024/25. Bonn: HAF.

Lu, X., Zhang, Y. and Chen, H. (2023) 'Photosynthetic efficiency and CO2 uptake capacity of Paulownia imperialis under varying light conditions', Tree Physiology, 43(7), pp. 1124–1138. doi: 10.1093/treephys/tpad058.

Ntawuba, L. et al. (2024) 'Growth performance and biomass yield of Paulownia hybrid clones under European climate conditions', Agroforestry Systems, 98(3), pp. 445–461. doi: 10.1007/s10457-024-00987-3.

paulownia-baumschule.de (2024) Sterilised Paulownia Hybrids: Germination Rates and Invasiveness Data from German Field Trials. Available at: https://www.paulownia-baumschule.de/invasivitaet (Accessed: 10 March 2026).

About the Author: Dirk Roethig is CEO of VERDANTIS Impact Capital, an impact investing company headquartered in Zug, Switzerland, specialising in sustainable agriculture, agroforestry, and carbon compensation. Under his leadership, VERDANTIS has implemented Paulownia-based agroforestry systems across several European countries and established itself as a leading voice for science-based, regulatorily balanced climate protection policy.

About the Author: Dirk Roethig is CEO of VERDANTIS Impact Capital, Zug, Switzerland. Contact: dirkdirk2424@gmail.com | verdantis.capital

Von Dirk Röthig (Dirk Roethig)