Edible Gardens

Visit Knepp’s rewilded Walled Garden

After a spate of days ruled by bouts of stormy rains, the large kindly face of a wax-yellow full moon rises into a still night, and ushers in the third heatwave of the year. Heatwaves are defined by the Met Office as when a location’s temperatures meet or exceed the ‘threshold temperature’ for at least three consecutive days. These vary from county to county. It is 27°C for Sussex. In the greenhouse, the heat peaked at 44.8°C. While the Walled Garden is mercifully cooler, the warmth is trapped and the sand and crushed concrete mix of the Rewilded Garden reflects white light that feels sharp enough to cut the air. The Mediterranean herbs – sage, thyme, the aniseed tang of fennels, the balm of rosemary and lavender – emanate heady and pungent scents, and a steady hum of bees, wasps and hoverflies accompany the flitting wings of butterflies and day-flying moths.  

It’s been a bumper year for butterflies across the UK, and particularly at Knepp where not only have we recorded the highest ever number of purple emperors, but there has been an upsurge in the number of GB Red List species  (species assessed as being of conservation concern in Great Britain) such as the wall brown butterfly.  

In the garden there’s a party atmosphere around the purple cones of buddleias and yellow daisy-like clusters of ragwort flowers, and flashes of orange, purple and blue from red admirals, peacocks, commas, small blues, cabbage white and meadow browns. Occasionally the air is suddenly vibrating with the exotic whirr of a hummingbird hawkmoth, its long probiscis darting into nectaries at dizzying speeds. Dianthus plants, sometimes called pinks, rely on hawkmoths for pollination, and plants from the Stellaria genus, like greater stitchwort, chickweed and many of the willowherb family, serve as food for their caterpillar stage. For that reason, we often leave what others might regard as ‘weeds’ in the garden, such as the hoary or square-stemmed willowherbs you often see on roadsides or disturbed ground. We have an ornamental white-flowered rosebay willowherb (Chamaenerion angustifolium ‘Album’) with its wonderful tall plumes in the Kitchen Garden. Its flowers, stems and leaves are edible, a good substitute for asparagus and can be made into teas. Hummingbird hawkmoths are considered a good omen in Italy and Malta after a swarm was seen crossing the English Channel by the armada on the day of the D-Day landings in 1944 that marked the beginning of the fall of Nazi Germany. Generally, they migrate from Europe and North Africa in May and June and breed here in the summer but with climate change there’s been an increase in recordings of hibernating adult moths overwintering in southern Britain. 

A hummingbird hawkmoth feeding on buddleia flowers 

When we talk about the climate crisis, we‘re really talking about a water crisis – either too much or too little. As we ease into peak harvesting season in the Kitchen Garden, the dry, hot spring and summer has sparked conversations in the garden team around sustainability, water usage, soil fertility, productivity and rewilding principles in an edible ecosystem.  

Deputy Head Gardener Suzi Turner talks about the ‘Golden Triangle’ in the Rewild Your Vegetable Garden Workshop that we hold in the Walled Garden and the organic Market Garden. This Golden Triangle is a hard-won confluence of elements in a Venn diagram made up of productivity, biodiversity and aesthetics. Invariably these three elements seem to act on a sliding scale – too much emphasis on one adversely affect another but get them right, and everything falls into place. Finding the balance between them is a constant juggling act for the vegetable gardener. The added complication of the effects of extreme weather applies further pressures.  

The universal metric the vegetable gardener generally applies to success in food productivity is quantity – abundance – a measure highly influenced by agriculture. But how does this view tie in with sustainability, water conservation and soil health? We know that intensive farming with artificial fertilisers and chemicals over the past fifty years has had devastating effects on the environment, particularly on topsoil and biodiversity in the UK. This month the National Farmers Union held an urgent summit to tackle the pressures of water and food security with representatives from DEFRA, NGOs, farmers and water companies taking part. The government has updated the 2022 Sustainable Farming Initiative (SFI) this year and the Environment Agency has recently published its National Framework for Water Resources. While the total water on the planet remains constant, only 2.5% is fresh water and only 1% is available for human consumption. So, can we implement changes in our growing spaces to prepare for the future?  

We’re often thinking about how our gardens are right now or look ahead in terms of months or even next season. Perhaps part of rewilding our minds is to look at our edible gardens as ecosystems and think about them over a much longer timeframe. Could we think about building soil health and learning to store and use water wisely as, say, a ten-year endeavour? 

There is much we can do to create ways to collect water – in tanks, troughs, ponds and water butts; harvesting grey water from household showers, baths, laundry and dishwashers; using drip irrigation systems; and slowing water loss by creating green roofs, rain chains and rain gardens, and by varying topography to hold water better.  Mulching round the collars of plants with aggregate, woodchip, leaf mould or compost can reduce water loss through evaporation – we were recently donated some sheep’s wool and are trialling it round perennial kales. Developing a seed list that includes drought-tolerant plants and favouring perennial vegetables that require less watering than annuals. 

Planting young kale into loam mounds with sheep’s wool mulch. 

Growing food in gardens and allotments can only be seen as a good thing. It reduces the carbon footprint of food and the use of chemicals, and supports our own gut biomes by growing healthier, more nutritious food than industrial systems. Vegetable gardeners can help preserve the diversity of plants by saving seeds of heritage varieties and seed swapping with fellow gardeners.  

In our experimental Kitchen Garden we’ve spent a few years developing ideas, and each season playing with different approaches. But always keeping what we’ve learnt about nature recovery from the wider rewilding project, the natural processes and the herbivores – the keystone species that drive those natural processes – in the forefront of our minds. 

In the wider rewilding project, nature is the primary ‘product’ and any food production that happens off the back of it – such as ‘wild range’ meat or foraging – is incidental, secondary to the primary purpose. On the flip side, with our regenerative farm which lies outside the rewilding project, food production is the primary goal and nature is the secondary beneficiary. 

We’re now starting to think about the Kitchen Garden more in terms of focusing on soil health and putting food production at the forefront, a small-scale nod to Knepp’s regenerative farm. In the Rewilded Garden, where soil fertility has been reduced with the addition of sand and crushed concrete to greater and lesser degrees, the focus is on broadening the range of habitats and plant selection and increasing biodiversity, just as in the wider rewilding project. 

But there is still room to play in the Kitchen Garden. In the smaller beds and paths and the margins around the walls where we’re not intensively growing fruit and vegetables we have space to mix it up – with perennial edibles such as artichokes, Solomon’s seal, sea kale and rhubarb, alongside edible flowers and fruiting shrubs, and unusual and challenging edibles, such as our Native American chokeberries, that benefit wildlife.  

Above all, learning and trialling methods from innovators such as Charles Dowding, Iain ‘Tolly’ Tolhurst and Joshua Sparkes who are revolutionising horticulture through techniques such as agroforestry, syntropic farming, no-dig systems, and forest gardening – is an important role for the Kitchen Garden. 

So where does biodiversity – the second aspect of the Golden Triangle – fit into our strategy for the Kitchen Garden? Wildlife, when talked of amongst vegetable growers is often known by another term – pests. How do we reconcile encouraging a broad range of beasts, birds and bugs and discouraging potentially the very same insects and animals with whom we are battling for our lunch? 

 Thinking of the vegetable garden as an ecosystem with complex food chains has an important role to play here. And patience.  Natural pest/predator relationships take time to build – if you are constantly removing aphids, why would the bluetits come? Natural predators like hoverflies and ladybirds are our best friends in the garden and having the patience to give them the habitat and time to establish will reap rewards. There’s merit in accepting that, one year, we may be without a crop when there’s a population surge in a particular pest that attacks a particular crop. It may take that pest’s natural predators a season or more to build in numbers and experience to effectively tackle the problem.  

There are plenty of creative things a gardener can do to counter pests without reaching for the pesticides or pest control. Finding weak spots in an adversary – the poor eyesight of pigeons, for example – can be exploited by blurring margins, allowing some plants to bolt around new seedlings. Or using companion planting, like sowing carrots amongst our onions – the strong smell of the onions deters carrot fly. 

One thing in nature is certain, there will always be change. We’re learning how to work with nature, rather than battling against it all the time, the key to an ecosystem- based approach to vegetable growing. 

Some of the Kitchen Garden’s July harvest. 

The last element of the Golden Triangle – aesthetics – is in many ways the trickiest. The nineteenth century Victorian polymath John Ruskin created a polemic on aesthetics and believed that seeing beauty in something was not a rational act, but an emotional and moral response. Beauty is, indeed, an emotional response and often we’ve grown up with irrational, preconceived ideas about what defines it. In both our gardens and our landscapes beauty is often judged by orderliness, tidiness and control. But if we start to look at them as ecosystems we begin to think differently, we begin to understand what underpins them, what they need to sustain life, to be abundant and sustainable. When we look at a barren hillside, or a monoculture lawn, and recognise how inhospitable it is as an environment, it becomes much harder to think of it as beautiful.  Thinking about the importance of wildlife above and below ground in a vegetable garden as allies to food production shifts the focus. Once we know the benefits of plant complexity, soil protection and insect life it becomes a challenge to  see beauty in our conventional inherited aesthetic of  bare soil and uniform rows of vegetables.  

Clearly, our discussions have given us an enormous amount to think about, but we hope that as this experimental project continues, we can share some of our discoveries. Patience, learning through trial and error, keeping records and taking the long view will help us gain the detailed familiarity with our patch that will get us through the worst of times, and celebrate the best of times. 

Photos courtesy of Charlie Harpur, Suzi Turner, Joshua Chalmers, Butterfly Conservation. 

Moy’s Garden Tips for August

1. Orchard & Wisteria summer prune – if you haven’t done it already, now’s the time to thin out the fruit on your apple and pear trees and cut back any water shoots in the centre to let air and sunlight in. Wisterias can be cut back now too to stop them getting too large and heavy. Loose the wispy new growth to 3 buds above the main stems.

2. Browsing evergreens and subshrubs – new growth on structural shrubs like bay or Mediterranean subshrubs like immortelle can be nibbled back to shape. We like to cut our bay for example, like a sculpture by Tony Craggs, giving them a greater surface area, increasing complexity. We think like a songbird or a moth in the rain, looking for shelter.

3. Annual and meadow seed collection – If you have a meadow and have managed to establish some yellow rattle, collect the seed and keep it dry. Spreading the fresh seed once the meadow is cut and cleared in late August or early September will help increase the yellow rattle and keep the grass from outcompeting the wildflowers. Early summer annuals like poppies, Orlaya, Ammi, Nigella, cornflower and marigolds will be seeding now. Collect, label and dry them now for next year, or presents for friends!

4. Editing and disturbance – volunteer plants (sometimes known as weeds) have become dominant with the warmth and rain. We edit out self-heal, fleabanes, clovers, disturbing the soil for solitary bees and wasps and leaving clear ground for self-seeding perennial seed.

5. Cue–to–care for late summer show – late summer flowering perennials like asters, dahlias and sedums may be crowded with other vegetation. Cut back or clear around them – giving a cue to care and letting them bask in their full glory. It’s a good time to make a note of any gaps where more late food for pollinators and an extension of flower shapes could be added in the autumn or spring ready for next year.

What we’re reading 

“A Big Year for Ragwort” – The Plant We Love to Hate – Knepp 

Rewild Your Vegetable Garden Workshop – Knepp Estate, West Sussex 

NFU sounds alarm on water crisis threatening UK food security – FarmingUK News 

An update on the Sustainable Farming Incentive  – Farming 

Water supply resilience and climate change POST-PB-0040.pdf 

The National Framework For Water Resources 2025 

England’s water crisis needs more than just new reservoirs – here’s what will help 

The Garden Against Time — Olivia Laing 

Charles Dowding: Home 

Home – Tolhurst Organic 

Birch Farm Woolsery | Natural farming in North Devon 

Creating a Forest Garden – The Agroforestry Research Trust