September: Super-harvests and falling in love with wasps 

Published October 2025

Visit Knepp’s rewilded Walled Garden

After months of sunshine and very little rainfall, the tail end of August brought with it the remnants of Hurricane Erin – a category 5 at its peak, sustaining 160mph winds as it travelled to us across the Atlantic. Above the garden, high skies paraded fantastical smoke-grey and soft-white, beast–shaped clouds. Gusting, dark masses intermittently released pelting curtains of rain, the sun chasing behind, the unfamiliar drumming on the greenhouse glass a deafening novelty. One overnight measurement on the rain gauge reached 33.2mm. 

The garden responded almost immediately, leaves plumped and lifted, wilting heads were raised up, and myriad tiny seedlings and grass blades appeared overnight. The faded corduroy greens of summer became a vibrant fizz of agate, lime and fern green, rinsed of dust. A rush of royal purple bloomed in a few days all through the crushed concrete-and-sand mix of Hitchmough ridge as the European Michaelmas daisy (Aster amellus ‘Veilchenkönigin’) burst into flower. Strictly speaking, they have come early. The Feast of Michael and All Angels (Michaelmas) is actually celebrated on 29 September.  Associated with the coming of autumn and the shortening of days, it’s traditionally one of four days through the year close to solstices and equinoxes (the others being Lady Day on 25 March, Midsummer on 24 June, and Christmas Day on 25 December), when servants were hired, rents became due and leases begun. It signalled the last day of the harvest and a well–fattened goose, fed on the stubble of the fields, was said to protect against financial need in the following year, while St Michael, himself, the warrior chief of the angels and archangels who fought against Satan, protects against negative forces in the dark months. There is still a Nottingham Goose Fair, named for the years when 20,000 geese were driven up from East Anglia and Lincolnshire to be sold and stuffed for the traditional Michaelmas dish. 

Before the darkness comes, though, there is still time for the ‘season of mellow fruitfulness’. It has been an extraordinary year for blossom and fruit – the hedgerows are full of laden boughs russet-red with hawthorn berries and the scarlet fruits of the guelder rose. Following last year’s wet autumn, the orchard was well watered and ready for the warm, dry, windless spring. None of the blossom was lost to frost, pollinators could roam freely and fruits form at their leisure. These conditions also favoured the queens of common wasps (Vespula vulgaris) in their first stages of founding nests, and provided an abundance of insects for them to eat. As our summer progressed through four heatwaves, however, some insect populations suffered. Bees can overheat and are unable to fly or forage, young caterpillars can be scorched, life cycles and metabolisms of some insects can become out of sync with flowering plants, or their food host plant becomes scorched and inedible. Plants under pressure from the heat and environmental stress produced fewer flowers for shorter periods.  

Even the wasps may have been affected. Tabloid headlines about ‘invasions’ of wasps over the summer are based not on scientific evidence (see below for surveying websites – it’s still too early for results) but from their more noticeable presence as their diet moves from insects to sugar. When the queen stops laying eggs, the need to feed the larvae declines. The quantities of sugar that the workers take from the larvae secretions comes to an end, and they turn to alternatives. Since plenty of our outdoor activities involve sugar, and we’ve spent more time outside this year in the good weather, we’ve inevitably seen more wasps, and it’s possible a shortage of other insects has also led them to seek sugar earlier. 

Wasps are an absolute necessity for any functioning ecosystem because of the number of insects they devour, keeping populations in balance.  Every UK summer, social wasps consume an estimated 14 million kilos of insect prey, including caterpillars, greenfly and blackfly.  As gardeners, when we see a wasp’s nest, we need to learn to breathe a sigh of relief rather than a gasp of panic – free pest control! 

When it came to harvesting the orchard, which was like a collection of children’s drawings of fruit trees – dripping with perfect, large red, yellow and green fruit – we shared the bounty with plenty of wasps. Neither we nor the fantastic Knepp volunteers and the team from Brighton Permaculture Trust suffered any stings while we were picking – they rarely sting unless they’re threatened with swatting or sudden movements. There wasn’t time to worry about wasps in any case, our hands were full with the harvest – a colossal haul of 1740kg of apples.  The Trust process the fruit for us and transform them into a delicious juice for the Wilding Shop and Kitchen, and this year for the first time we’re using the windfalls to make apple cider vinegar. It’s also been the best year for damsons, plums and greengages too, but sadly, the birds are still winning the cherry race. 

It’s been a month of visits and visitors, including the inspiring Talking Plants Symposium in Sheffield. A two-day symposium of talks, debates and workshops for professional and amateur plantspeople, the hall was buzzing with designers, gardeners, ecologists, florists, landscapers and growers. The key themes were substrates (planting mediums), biodiversity, planting design, and garden management and maintenance – although even this last word was a hot topic, with ‘care’ or ‘stewardship’ suggested alternatives.  

Our main takeaways were on the subjects of sustainability and resilience. On sustainability, we appreciated the discussions on the effects of our actions further down the line and finding innovative ways to solve problems, rather than passing them on to another site. Re-using on-site ‘waste’ and recycled materials and factoring in the costs and risks of what we use, and how the supply industry is behind the curve on sustainable products and infrastructure.  On resilience, the discussion was of designs and planting schemes; meadows and their best management for biodiversity; plant species in urban settings where temperatures are highest, particularly London, that are no longer able to survive in the heat; how to build longevity into designs – will they still work as a plant community seven to ten years in? And the importance of the gardener and the gardener’s role in taking a design forward.  

In our Rewilded Garden experiment Tom Stuart-Smiths design is a starting point – the garden is intended to develop in ways that are not entirely predictable, the gardeners as the ‘agents of disturbance’ driving change. 

Above all, though, there was a refreshing focus on plants themselves, a celebration of their beauty and diversity and all who have a relationship with them, including insects and wildlife. There were some fantastic speakers on insect life in gardens and meadows – as the entomologist Dr Linda Birkin reminded us, over half of all living things are insects. It’s often a missing element in horticultural conferences. 

Back in the Walled Garden at Knepp, there was an incredible array of career diversity in the group from the Young People in Horticulture Association. The YPHA as they’re known, was formed in 2020 to unite under 35’s working in horticulture and their focus is on collaboration, education and innovation. They have over 900 members nationwide, and our visitors came from all over the UK – Scotland, Cumbria, Wiltshire, Shropshire, London and Surrey and Norfolk from a range of horticultural settings. A group of thirteen of them were interested to learn about the design of the garden, and the way we approach horticultural tasks, taking our cues from the behaviour of the free-roaming herbivores in the rewilding project.  So they  joined us for a spot of grazing in the garden. Below the Kitchen Garden beech hedge, the ‘dirty path’ – as our garden designer Tom Stuart-Smith refers to them – has become blurred with self-seeders in the gravel cap that sits on a topsoil and gravel mix beneath. Oregano, yarrow, wild strawberries and ox-eye daisies relish these conditions and whilst they’re all wonderfully beneficial plants for pollinators they’ve become dominant and reduce plant diversity, crowding other less boisterous species like the lavender, rosemary, thyme and Chilean myrtle (Luma apiculata). Clearing some space around them gives these plants more air and light and makes the path more ‘readable’ when it comes to harvesting the herbs. Like the herbivores, we indulged in some selective grazing, pulling out the plants that were most plentiful. 

As we worked, our conversations covered everything from the best organic slow-release fertilisers and peat-free compost brands to some intriguing natural solutions for how to deal with over-zealous mammal populations (older queen cats for predating voles, and planting what badgers love in vegetable beds that need digging over – the badgers do all the work!). Sharing stories is by far the fastest and most enjoyable way to learn.   

 Autumn is upon us, the frenzy and rush of summer easing into the distance. Time to prepare for slowing the pace, to listen to the stories the garden has told us this year – to observe, reflect and adapt. 

Photos courtesy of Charlie Harpur

Garden Tips – October 2025 

1. Herd disturbance – ‘browns’ – as the autumn gets into its stride, more leaves and stems die back. We therefore curate the visual brown-to-green ratio in the garden, moving through and disturbing the landscape, cutting or pulling in a random way as a herd might. Some material is dropped, some is used to create winter habitats, some is cleared away for compost and some is left standing. 

2. Herd disturbance – ‘greens’ – in the more impoverished areas of the garden (concrete and sand-based soils), we ‘graze’ relatively hard, reducing the biomass to keep the fertility of the substrate down. We’ll use it for our compost heaps. We remove species that are dominating and swamping others, creating patches of bare ground and over-sowing with more species to increase diversity. 

3. Hedge cutting – as the grass begins to slow its growth, herbivores will browse the new tender tips of woody hedgerow plants. We’ll trim our beech hedge too now all danger of nest disturbance is over, and the plants are moving into dormancy. We cut in an irregular waving pattern, to increase surface area and create aspects, microclimates and niches for insect and bird winter habitat. We leave any flowering ivy, as it’s the most important winter evergreen in any garden. 

4. Seed collecting and autumn sowing – we’ll be disturbing and scattering some seed in-situ to mimic natural systems, leaving some seedheads for birds, and collecting some to sow. We’re also continuing to sow hardy annuals for earlier growth in 2026, and perennials to try in our concrete substrate areas that need a winter chill to germinate. 

5. Planting out – the cuttings of woody subshrubs like lavenders and rock roses that we took last autumn are ready in our nursery sand beds. We’ll lift and plant them directly into the concrete-and-sand mix while the ground is still warm, leaving the autumn rains to water them in. In the Kitchen Garden, we’re planting the last of the spring-sown edible perennials like nettle–leaf bellflower (Campanula trachelium) – wild greens that are used in Italian cooking, and they’re particularly important for solitary harebell and scissor bees in the summer. 

What we’re reading 

Nottingham Goose Fair 2025 Dates + Info | GooseFair.co.uk 

Bees Wasps & Ants Recording Society | BWARS 

Welcome to the UK Pollinator Monitoring Scheme (PoMS) | PoMS 

The Big Wasp Survey – Citizen Science = Wasp Love! 

The long‐term population dynamics of common wasps in their native and invaded range – Lester – 2017 – Journal of Animal Ecology – Wiley Online Library 

Complex responses of insect phenology to climate change – ScienceDirect 

YPHA – Young People in Horticulture Association 

Talking Plants Symposium 2025 — Talking plants 

Wildlife Gardening Forum 

Identifying-open-mosaic-habitat.pdf