September
In collaboration with Charlie Harpur
September Growing Guide – Charlie Harpur
At Knepp Wildland, September is one of the most rewarding months. The air is fresh, the light softens and the whole landscape feels alive with fruit, seed and movement. My work here is all about rewilding – working with nature to create a garden that is full of life, resilient, and beautiful. This September growing guide is about striking that fine balance: harvesting what we need, guiding the garden with a light touch and leaving plenty for the wild residents that call Knepp home.
Image: Knepp Wildland
Hedgerow care
Hedges at Knepp are vital corridors for wildlife, so we cut them just once a year and only after the bird nesting season (March – August) has finished. In September we trim back our beech and other hedges – not to rigid, or formal shapes, but into soft, organic lines. This keeps them dense and healthy while still providing cover and food for birds and insects.
Bulb orders
September is also the month we plan our bulb orders for the walled garden. Our choices are guided as much by ecology as by design – we want bulbs that extend the season of nectar and pollen for pollinators, as well as bringing joy to visitors. This year we’ll be adding narcissus, cyclamen, iris, muscari, scilla and allium. We’ve learned over the years which bulbs the voles leave alone, so we stick with those – rewilding means working with what’s here, not fighting against it.
Image: Knepp Wildland
Harvesting highlights
The orchards are alive with fruit and buzzing with life. We’re picking plums, damsons, gages, apples and pears. Much of the harvest becomes organic juice for the Wilding Kitchen. What we can’t reach, we leave – along with windfalls – for birds, badgers and insects to enjoy. A rewilded orchard is as much about feeding the ecosystem as it is about feeding ourselves.
Seeds – collecting & sowing
Seeds are the lifeblood of rewilding and September is a month full of potential. At Knepp we:
- Collect perennial seed from the walled garden to propagate.
- Scatter seedheads to mimic natural dispersal and encourage natural regeneration.
- Leave plenty for birds and small mammals to feast on over winter.
Image: Knepp Wildland
It’s also still warm enough to sow:
August isn’t just about picking—it’s also a crucial time to maintain plants and prepare for the seasons ahead.
- Late vegetable crops like spinach, salad leaves, and hardy brassicas.
- Autumn annuals such as poppies and cornflowers, which root in now and leap into growth come spring.
Cues to care
A rewilded garden isn’t a free for all – it still needs thoughtful editing. September is when we gently intervene to keep balance. We graze (weed) ruderals that would otherwise dominate, rake paths and pile the fallen organic matter into habitat heaps and build features like dead hedges and log stacks.
These are what Joan Nassauer calls ‘cues to care’ – visual signals that show this isn’t neglect but intentional stewardship. Visitors see that the wildness is purposeful, not abandoned, which helps them connect with the space.
Image: Knepp Wildland
Wild lawns & grassland
This is the time to boost diversity in wild lawns and meadows. Sow a mix that includes yellow rattle to reduce grass vigour, or strew species-rich green hay from a local meadow. Leave it on the surface for a fortnight to let the seeds ripen and drop before removing.
Cuttings
We also take semi-ripe cuttings now from herbs such as sage, rosemary and thyme. They go straight into an outdoor sand frame, where they root quietly over winter. Next year we have a new generation of plants ready to join the garden.
Image: Knepp Wildland
Final thoughts
September at Knepp is about cooperation, not control. We harvest, sow, trim, and tidy – but always with the bigger picture in mind. Every pile of sticks, every patch of seedheads left standing, every hedge shaped softly rather than sharply is a small act of rewilding. It’s a month for shaping a garden that supports life in all its forms.
About the author
Charlie was our guest speaker at our Annual Lecture 2025 – a fascinating discussion on rewilding and how it shapes the work at Knepp. Charlie Harpur is Head Gardener at Knepp Wildland, one of the UK’s most influential rewilding projects. He creates spaces rich in biodiversity and beauty, showing how gardens can be places where people and nature thrive together. Knepp is open to visitors, with guided tours and self-led walks offering a chance to see wildlife, habitats, and people coexisting in a thriving landscape.
Where to find out more
Instagram: @charlie.harpur
www.knepp.co.uk
September brings a golden shift in the garden, alive with fruit, seed and movement. This month we work with rewilding in mind – trimming hedges softly after nesting, scattering seedheads and leaving plenty for birds and insects. Bulbs are ordered for spring pollinators, late salads and hardy annuals are sown, and herbs are taken as cuttings to root over winter. Each small act strikes a balance between harvest and habitat, keeping the garden full of life as autumn takes hold.
