Woodland Creation at Scale: Trewithen plants 24,000 trees

Beyond Carbon Capture

While carbon sequestration is a vital part of the project - which is expected to capture around 29,000 tonnes of carbon over the first 50 years of growth - the wider ecological value the new woodland will bring is equally exciting. The woodland has been carefully designed to buffer and extend existing habitats, linking fragmented areas of tree cover and creating stronger wildlife corridors across the estate. We are grateful for Zora Ecosystem’s technical expertise and support in bringing the project to life. 

A Living Mosaic

The new woodland has been planted with a rich mix of 15 native and naturalised broadleaf species, ranging from pedunculate oak to crab apple. The planting palette carefully reflects the neighbouring ancient woodland that has shaped this landscape for centuries, helping to create woodland rooted in place, while building resilience in a changing climate. Across 16 individual compartments, species have been selected to suit varying ground condition. Near beaver-created wetlands, common alder will thrive in wetter ground conditions, while dogwood and hawthorn will create shrubby edge habitat, adding structure and diversity within a rich mosaic environment.

The Return of the Pine Marten?

The importance of connected woodland ecosystems has been brought sharply into focus by the recent appearance of a pine marten at Trewithen. The exciting spot was captured on a wildlife camera monitoring water voles reintroduced with Kernow Conservation last year. Having been pushed to the brink in England, pine martens’ return relies on extensive, healthy woodland habitats. By creating larger, more connected habitats, we hope these new woodlands will allow not only pine martens, but countless other species that depend on diverse, resilient environments, to thrive.

Rooted in the Future

As with the first phase of planting, we have used wool mulch mats and 1.5 metre Tubex guards to give the young trees the best possible start. Retaining moisture and reducing competition from surrounding vegetation is vital during the first few years of establishment, and the wool mats provide an organic alternative to chemical herbicides. We've discovered one unintended, though rather charming, use of the mats - voles have taken to nesting beneath the wool!

Alongside this year’s planting, we have completed the summer ‘beat up’ of last year’s planted compartments, replacing trees that have failed to establish. Happily, over 80% of the original planting has taken well, with many young trees already emerging above the tops of their guards. Ongoing maintenance throughout the summer remains important to maintain areas of open ground and lines of sight designed into the planting scheme. Particularly, controlling vigorous grass growth around the trees will give the woodland the strongest chance to thrive in the years ahead. 

Agroforestry: Integrating Trees with Farming

Alongside this year’s woodland creation, we have also established an agroforestry project across the estate: in-field tree alleys across three fields have been designed with the farm system to support mob grazing. By naturally subdividing larger fields into paddocks of around eight acres, livestock can be more easily moved frequently, to the great benefit of pasture recovery and soil health. The alleys design centres around a belt of specimen trees, flanked by rows of browsable species: goat willow and grey willow, in particular, provide valuable forage and nutrition for cattle, while blossoming wild cherry will support biodiversity. Amongst the broadleaf planting, Scots pine and Western red cedar will also provide a timber crop.

Trees from Trewithen Gardens

We are delighted that many of the trees planted have exceptionally local provenance. Alongside Cornish-grown trees supplied by The Grower, we have incorporated beech, oak, sweet chestnut, wild cherry and hawthorn grown from Trewithen Gardens seed and carefully nurtured by Lanjeth Nursery - carrying a small part of the garden’s landscape forward into the next generation of planting.

We are grateful for support from Forest for Cornwall, whose farmer and landowner-led approach has been instrumental in bringing projects like this to life across the county. Like much of our work across the estate, this project is rooted in learning by doing. The planting provides an opportunity to explore what works best within this particular farming system and landscape. In time, we hope the lessons learned here will inspire more agroforestry planting across the estate, working collaboratively with tenant farmers to support both productive farming and our environment.