Denbighshire County Council’s Tree Nursery is successfully propagating vital native Aspen trees to assist with biodiversity, carbon capture and climate resilience initiatives…and Air-Pot containers are playing a key role.

The nursery has produced around 100 rapid carbon-capturing Aspen trees in three litre Air-Pot containers with plants reaching 120-180cm tall and demonstrating exceptional root development and vigorous growth.

Keegan Blazey, a Tree Nursery Officer from DCC’s Ecology and Biodiversity Team, explains: “As part of our work to address the climate and nature emergencies declared by the Welsh Government, we’re using techniques developed by Aspen specialist Dr Jenny Wong, Honorary Lecturer at Bangor University and Director of Wild Resources Ltd, to propagate Aspen.

“Aspen (Populus tremula) is increasingly recognised as a valuable species for future landscapes because it can tolerate both drought and flooding, supports a wide range of wildlife and can rapidly capture carbon. The species also plays an important role in flood mitigation and is a preferred food source for European beavers.

“Often described as second only to oak for biodiversity value, it also has significant potential to help replace some of the ecological functions being lost through ash dieback.”

As climate conditions become increasingly unpredictable, with growers needing trees capable of withstanding both hotter summers and colder winters, experts believe greater tree diversity will be essential to building resilience into future landscapes. Aspen is viewed as an important part of that mix due to its wide natural climatic range and ability to establish across varied environments.

Keegan continues: “Air-Pot containers have been instrumental in establishing strong, healthy root systems, giving these important trees the best possible chance to thrive and helping us maximise the environmental benefits they can deliver.”

At DCC’s Tree Nursery, root cuttings were collected from a flowering female Aspen stand and propagated using techniques developed by Dr Wong. Root sections were initially placed in Air-Pot propagation trays and grown in carefully selected growing media to encourage healthy shoot production.

Aspen can be challenging to propagate because male and female trees often exist in fragmented populations and successful seed production can be limited. As a result, specialist propagation from root cuttings and shoots is often required to increase tree numbers for conservation and restoration projects.

Once rooted, young plants were transferred into three litre Air-Pot containers, where they achieved remarkable growth rates of approximately one metre within a month. The nursery team found the containers encouraged the development of dense, fibrous root systems while preventing root circling and girdling.

Strong root establishment is particularly important for Aspen, which naturally develops extensive underground rhizome networks. The Air-Pot system enables roots to fully colonise the growing medium, helping plants continue growing until the available soil volume is fully utilised.

Dr Wong says: “Over the past few years we have been developing a low-tech technique for propagating Aspen from root shoots for planting out in Eryri National Park. We are delighted to see Keegan putting the training into practice and achieving such impressive results. After only a few months, Denbighshire’s young Aspen trees are already ready for planting out. Aethnen eto indeed!

“Aspen is a remarkable native species which may have been present in Britain since the last Ice Age. It can thrive from sea level to mountain environments, supports exceptional biodiversity and has an important role to play in both climate adaptation and conservation. We need a broader diversity of tree species in our landscapes to build resilience for an uncertain future climate.”

Aspen is regarded as a keystone species and an ecosystem engineer, supporting a rich array of insects, mammals, fungi and lichens. Fast growing and capable of creating natural green firebreaks, Aspen can also provide a sustainable fibre source for paper production.

The species is also the preferred food source of European beavers. With beavers expected to become part of future conservation work associated with the nursery, DCC is growing Aspen to support both habitat creation and biodiversity enhancement projects.

The nursery’s experience has also highlighted the importance of root development in helping young trees cope with increasingly challenging weather conditions. While bare-root Aspen planted on the site’s nature reserve did not survive recent heatwaves, container-grown Air-Pot specimens have continued to develop robust root systems that are expected to improve establishment and reduce transplant shock when planted out.

As demand grows for tree species capable of withstanding both drought and flooding, Aspen offers significant potential for climate adaptation projects across the UK. DCC believes Air-Pot technology can help overcome some of the challenges associated with propagating and establishing the species at scale.

Georgie Single, Sales & Marketing Representative at Air-Pot, says: “We are so proud and absolutely delighted we have been involved in this vital work. Projects such as this demonstrate how healthy root development can support both conservation goals and climate adaptation objectives by giving trees the strongest possible start in life.”

Air-Pot containers are pioneering root-air-pruning technology designed to produce healthy, vigorous root systems for plants of all sizes.

They are designed to eliminate root circling, promote a strong fibrous root system and support long-term plant resilience.

Used by growers, nurseries, botanic gardens and research institutions worldwide, the system enhances growth, resilience and long-term plant performance.

By promoting stronger root development during the nursery phase, Air-Pot® containers are helping DCC produce healthier, more resilient trees capable of contributing to biodiversity enhancement, carbon sequestration and long-term landscape resilience.

For further details, please visit www.air-pot.com/nursery/