
Moy Fierheller | Deputy Head Gardener
The garden is in slumber. A watercolour wash merging sky and land in slatey greens and greys. The strident chattering of a robin in the bare branches of an ornamental pear tree (Pyrus nivalis) or the squeaky-wheel chirrup of blue tits feeding off standing seedheads the only sound. Occasionally a white stork wheels above us, investigating the many chimneys of the house as potential nesting sites. Around 25 storks overwinter at Knepp instead of undertaking the migration to warmer climes, many of them from the original cohort brought to Knepp from Warsaw Zoo, Poland in 2016, although there are a few younger Knepp-hatched fledglings that remain. The bones of the garden have come to the fore – grasses moving from orange through russet to bone-white, beaver-brown stately dead stems waving geometric shapes of seedheads – the inflorescences of giant fennel (Ferula communis) and hog fennel (Peucedanum verticillare) and the cones of the great coneflower (Rudbeckia maxima) and pale purple coneflower (Echinacea pallida) against sprays of bottle-brush grass seedheads like Chinese fountain grass (Pennisetum alpecuriodes ‘Cassian’s Choice’).

Great cone flower (Rudbeckia maxima) before and after songbirds have eaten the seeds.
The high winds Storm Darragh brought at the beginning of the month left us relatively unscathed – in the West Country over 2.3 million households lost power due to winds of up to 90mph – but it has been an exceptional year of wind and rain. The south of England experienced the wettest February since 1836. Despite a dull and cloudy spring, the average temperature for May across the UK was the warmest on record, but it was the coolest summer since 2015. The Met Office reported that 2024 was provisionally the fourth warmest year on record, part of a warming curve since 2000 that is a clear illustration of climate change. So how has the garden fared this last year?
It began with good news – the invertebrate survey summary report by pan-species recorder Graeme Lyons (conducted in 2023), came back to us. From the baseline survey before the redesign of the garden in 2020 there has been a 33.3% increase in species – up from 333 species to 434. The main upsurge is in the number of beetles – Graeme identified 22 more species, many of them with conservation status. We’re hopeful these figures will be part of a rising trend in response to our management of the garden; leaving more curated dead material through the year; mimicking the natural processes we observe in the free-roaming herbivores in the rewilding project and staggering our impact with disturbance, grazing (weeding), and browsing (pruning); allowing the ephemeral pond to fill with rainwater in winter and dry out in summer, and focusing on constantly creating new opportunities and diverse habitats. These are all part of our experimental methods to encourage biodiversity in a garden setting.
Our year saw us sharing these ideas with 2,531 visitors, twelve horticulturalists on work experience placements and 20 days with the Knepp volunteers. Other visitors have deepened our understanding of the natural world – Matthew Shepherd and a team from Natural England spent four days in the garden exploring the soil, the life within it and sharing their discoveries and ideas for creating citizen science garden soil testing and monitoring. Michael Kennard from Brighton’s Compost Club took us on an in-depth tour of better compost creation and familiarisation with what ‘living’, healthy compost looks like.
We discovered more about aggregates and invertebrate habitat when Head Gardener Charlie Harpur visited Peter Korn’s garden and nursery, Klinta Trädgård in Sweden. His visit with Deputy Head Gardener Suzi Turner down to Birch Farm in Woolsery, Devon, was an exploration of their Head Gardener Josh Sparkes’ vision for producing food in a regenerative and sustainable way, supporting above and below-ground diversity.
Josh Chalmers – who splits his gardening time between the Walled Garden and Knepp’s Wilding Kitchen & Shop site – took a trip to the Serge Hill Project in Hertfordshire. The project links horticulture and health and wellbeing and was created by landscape architect Tom Stuart-Smith (who designed our Rewilded Garden) and his wife Sue. Josh learnt more about the resources there, particularly the design and collation of their plant library (which our Head Gardener Charlie Harpur originally curated) and, in a workshop with Local Works Studio, investigated landscape design using locally sourced materials.
The garden itself has been busily adding another season of growth and establishment, regardless of the dull and rainy summer, some species romping away while others try to hold their ground, and we have augmented the plant diversity with annuals, more perennials grown from seed and some woodier species. Many of these went into the Kitchen Garden – expanding the range of unusual edibles. As well as growing 161 varieties of salads, roots, legumes, brassicas and squashes, Suzi found success with New Zealand spinach, Huacatay black mint, mountain and red veined sorrels, lemon clover, the tuberous roots of oca and yacon, and fruits like pink currant, worcesterberry and jostaberry.
We’ve increased habitat complexity too, adding some shitake and oyster mushroom inoculation dowels into stacks of logs in the Kitchen Garden. Carving out two ‘engagement’ paths of woodchip in the larger beds of unusual edibles, we look forward to easier harvesting and immersion in the planting next season. In the Rewilded Garden we layered onto the existing 3D topography fine-grained Thanet sand cones for mining and other solitary bees, sharp sand mounds and large upright logs, and have begun with the creation of a pergola from ‘stag’ oaks – the dead limbs that protrude from the crown of living oaks.

An oak log stack inoculated with shitake mushroom dowels in the Kitchen Garden
Like any experiment, we’ve encountered disappointments as well as successes. In the three years since its creation, the crushed concrete and sand mix of undulating terrain and the plant choices in the rewilded Walled Garden have shown resilience to extremes in temperatures (from –10°C to 39°C), but the cool wet spring and summer highlighted compaction issues – some plants struggled to thrive with their roots unable to dry out. Hence the addition of mounds, replacing the plants into deeper layers of free–draining sharp sand after breaking up the compacted layer. The Kitchen Garden vegetable area was treated to a deeper degree of disturbance with a mini digger turning over the hard pan we discovered beneath the covering of compost.
Despite researching at length spring-flowering bulbs that were unattractive to rodents, shortly after planting a moderate number of narcissi, iris and fritillaries this autumn, voles made neat tunnels into the sand in suspiciously similar places to where the bulbs had been buried. Kestrels can catch between four and eight voles a day, and since they can see in near-ultraviolet light, they’re able to detect small mammal urine trails by their burrows. Their method of hunting by hovering motionless except for the beating of their wings, a familiar sight along motorways, favours the confined nature and undulating topography of the Walled Garden. To encourage nesting nearby we installed two kestrel boxes attached to oaks just outside the walls. Kestrels conventionally nest on cliff edges or in tree hollows but attaching the boxes at their preferred height above 4.5 metres, facing away from the prevailing winds gives them optimum safety for their young from predators and bad weather. We hope to see a reduction in the high population of voles in the coming year in consequence.
Our experimental cover of bracken and pampas on the tree echiums (Echium pininana) last winter sadly failed to keep them frost-free and alive. This season, inspired by Urban Jungle Nursery in Norfolk, we fashioned a series of roofed structures protecting the growing tips of new plants, made from hazel poles and coverings of hollow pampas stems and cut raspberry canes. Two hard frosts in, they are intact. Cause for cautious optimism.

Frost protection structures for a tree echium.
We are mindful that while as gardeners we might see these as setbacks, in the rewilding mindset this is all part of the dynamism of nature. There are no failures, only opportunities for a different species. Not all the echiums were covered. They are standing dead now – perhaps those darkened leaves will furnish a songbird’s nest. Waste is a human construct. There is no such thing as waste in nature. Those vole holes might prove prime real estate for a queen bumblebee.
The coming year will bring more surprises, more understanding and discoveries in this garden ecosystem. In 2025 the resumed sessions of the UN Biodiversity Conference will be held in February in Rome, and November sees COP30 hosted by Brazil, where the first Earth Summit was held in 1992. President Luiz Inacio Lula da Silva has prioritised climate change and the environment during his term and Amazon deforestation has reached its lowest level in nine years. In the UK, habitat creation and species recovery are prioritised with the finalisation of Local Nature Recovery Strategies. Glimmers of hope and positive change in 2025.
Photos courtesy of Karen Finley, Charlie Harpur, Tom Burns.
Visit the Walled Garden for a tour or workshop. Find out What’s On at Knepp.
What we’re reading:
Macdonald, B, Cornerstones, Bloomsbury Publishing, 2022
Birch Farm Woolsery | Natural farming in North Devon
About | The Serge Hill Project
(PDF) The diet of Kestrels in relation to vole abundance
Natural England Action Plan 2024 to 2025 – GOV.UK
Understanding Local Nature Recovery Strategies (LNRS) – UK Planning Law Blog
Convention on Biological Diversity pr-2024-11-27-cop16-en.pdf
The climate crisis: 5 things to watch out for in 2025 | UN News