A heritage response to a contemporary pathogen

Arduaine Garden is the 8-hectare creation of James Arthur Campbell and his wife Ethel, who between 1897 and 1929 embarked on designing and constructing a garden housing both native species and exotic plants from all over the world. The garden is afforded protection by its shelterbelt plantings which function as a windbreak, creating the desired microclimate to grow plants that have no earthly business living so close to the salty Atlantic seaboard.

The unique character of the garden lies in its relationship with one species of tree, the Japanese larch (Larix kaempferi), complemented beautifully by the understorey plantings that together represent 95 geographical regions of the world.

The problem

The garden is facing perhaps its most difficult challenge since its inception. A Statutory Plant Health Notice (SPHN) has been issued, instructing the Trust to remove all 885 Japanese larch trees by 31 March 2022 due to the increasing occurrence of the pathogen Phytophthora ramorum. The deciduous nature of the larch and the almost unique biology of the pathogen mean that the tree perfectly helps sporulation and the subsequent spread of the pathogen. A report and project plans were duly written that set out the detailed logistical plan for the transformation of the shelterbelt.

This may sound simple enough in written text or the spoken word. But the practical reality is far from simple. The bulk of the plant collection was planted at the same time as the larch, meaning the garden has matured in synergy, which makes it extremely difficult to remove the larch without causing significant damage to the understorey.

An analogous way to appreciate this project is to imagine removing the roof, bricks and structure of a house without causing any damage to the possessions inside!

This challenge was initially perceived as a destructive operation. But I would argue that, if delivered properly, the Trust is creating one of the best opportunities a horticulturist could have to curate, design and plant a new diverse, resilient woodland. After all, no gardener has done this in almost 100 years!

The plans

People

For the Trust to deliver this project, we rely on the input and understanding of a diverse range of people and stakeholders, both internal and external to the organisation. And because this is not just a garden project, we cannot forget our colleagues in the regional teams who have all had a part to play in bringing the project to fruition, especially the arborists from Mar Lodge Estate and staff from Crarae Garden.

Health, safety and environmental considerations

Removal of 885 mature trees is not only a visually devastating operation, but also one that is fraught with risk – risk of causing an injury to a member of staff and risk of causing damage to the local environment. With this in mind, a detailed Aspects and Impacts register was created to detail the various elements that should be managed to minimise risk and mitigate our environmental impact. An example of this is conducting ecological surveys at key stages of the annual felling phases to ensure operations cause minimal disruption to protected fauna like red squirrels and bats.

Communications

This, in many ways, is where projects can quickly come undone. If internal and external stakeholders don’t know or appreciate the details and context of what is being undertaken, how can they support the work? It’s quite simple really – communication is key. A charmingly funny example of the extent of our communication drive happened on a beautiful sunny evening in 2019, when Head Gardener Gregor Anderson and I were due to give a presentation in a local village hall. Despite our best efforts to promote the evening, only one person turned up – suffice to say that this person received the most thorough presentation given to date!

Felling operations

Under the terms of the SPHN, we have to fell the larch and burn all branches and arisings. However, we’re left with many tonnes of ‘waste’ timber and we’d have to pay for its removal and transportation to an approved sawmill for processing. So we purchased a sawmill! Now this timber can be milled to order and used in all Trust properties for cladding, fence posts, timber edging, dahlia stakes, tree stakes, sleepers, etc. This is recycling at its best, creating a resource-efficient solution to a waste problem. Any surplus timber will be chipped back onto the woodland floor to mitigate the carbon loss from tree removal while helping to improve soil content and structure. We’ll also use the timber in the garden itself.