November rains finally ease and cold begins to seep into the mornings. The crowns of the oaks defiantly cling to their leaves, outlasting their naked, skeletal neighbours of sycamore and willow in shades of marmalade – from blood orange to dark Seville, reflecting in the still water of the lake.
To brighten the darkest month, we were lucky enough to embark on a team visit to Hilldrop, the Essex garden of John Little. Originally, a designer and installer of grass roofs, he soon began to observe the natural phenomena of his roof seed mixes populating the surrounding aggregate of his clients’ driveways. He noted how the diversity and dynamism of the emerging plants increased and began experimenting with ‘waste’ construction materials over a twenty-year period. He describes his four acres as a ‘brownfield garden’, mimicking those biodiverse hotspots. But this description belies the beauty of the seed-mix planting of high summer.
However, we wanted to see the winter bones, how John has brilliantly created dense clusters of diverse habitats: gabions – (a welded wire cage used in the construction industry) – filled with rubble, bamboo straws, logs drilled with holes, and recycled plastic containers that catch falling leaves and rain (a perfect larval habitat for flying pond insects.)They even have built-in hidden ‘voids’attached to access pipes where small mammals might safely nest Beneath a ringbarked, pollarded sycamore, lies a flat circle of 30mm crushed aggregate held by a curve of sand bank that grades into a long mound of larger, 100mm-sized brick and rubble. Five diverse layers of complexity in a four-metre, three-dimensional cube. There were rows of test beds trying the same seed mix on crushed ceramics; recycled sharp sand; chalk waste from Tate and Lyle’s sugar processing factory; a circular mound of crushed brick; and a grassy slope with long, short and scalped cutting regimes. We were inspired by a general sense of creative experimentation. Fleabane and grasses dominating a bed? Simply add a 300mm layer of waste aggregate and re-seed. Retired wooden telegraph poles become sentinel standing habitats cloaked in ivy and pop-up compost heaps made from hoops of mesh punctuate the garden.
Although the rewilded pool garden at Knepp is now a long way from the two-dimensional croquet lawn it once was, replaced with mounds and hollows of crushed concrete and sand, what we saw here expanded our horizons. Both the walled garden and the garden design Charlie is creating for the new Knepp café and shop, will benefit from seeing how waste products can successfully provide both habitat and beauty.
Back in the garden, the forecast for plummeting temperatures prompted two discussions. The first was, in a rewilding setting, should we be protecting the more tender species? The dilemma of course, is that weather and death are two natural processes, and would our intervention be interfering? One side of the story is that the plants have been in the ground only a year, and for many of these young species, this is not enough time to establish woody growth or root formation. We remind ourselves of the advice of Alastair Driver, head of Rewilding Britain, who says that any project should have a sprint start and a marathon finish. High intervention to set natural processes going, and a gradual decline in management thereafter. We chose those plants most at risk, using natural materials as protection wherever possible; layering leathery magnolia leaves onto the spikes of the agaves; resting fallen cedar limbs against climbers; and piling evergreen branches on top of tender crowns.
We made an exception with the tree echiums (Echium pininana), swathing them in plenty of horticultural fleece. They are biennial in their native Canary Islands, and monocarpic: each plant dies after flowering, although its immense spire of hundreds of small blue flowers leaves a generous dispersal of seed behind. In this country, they can take anything up to four years to flower due to our shorter, cooler summers so our desire to initiate a seeded generation overtook our aesthetic and creative sensibilities. In the process of working our way through the plants that needed attention we discovered that one wild animal was being particularly well accommodated. So followed our second dilemma. Field voles live in grassland, moors, and heaths and, according to the Wildlife Trust, number a population of 75 million in the UK. Although we are not encountering hoards, there were plenty of tell-tale neat holes in the sand shortly after we planted 6,000 bulbs of different species last month and, moving through the old peach house bed, we saw that some had been busy gnawing through the bases of several Cupid’s dart plants (Catananche caerulea) and grazing the German pinks (Dianthus carthusianorum). Voles can produce up to seven pups between three and six times a year, and every few years undergo a population boom, although their lifespan is only one year. In the wild, they provide an important, year-round food source for birds of prey, weasels, and barn owls. Should we try to control the numbers in a rewilded garden? Again, our discussions came back round to the juvenile state of the garden. When the plants have self-seeded or bulked out and established themselves, we will probably welcome a little natural thinning out by voles. Looking at the damage inflicted this year and recognising that our presence and the garden walls reduce the chance of animal and bird predation, we decided to set traps for a short while, both to assess the population and rebalance the predator/prey ratio.
The temperatures did indeed plunge headlong into icy regions – the ferocity and duration of the frost and brief snowfall took us by surprise The garden froze solid for a week and a half. The cold side of the greenhouse showed –0.3°C and the garden fluctuated between –6°C and –10°C. The Met office reported the month as the coldest since 2010. Seedheads became an array of elegant sculptures of spheres, wings, cascades, chandeliers, feathers, and spires. The tree dahlias that had reached over two metres with thick stems the size of fists -that sadly, were just forming their first flower buds – became black, skeletal silhouettes. The snow revealed wild visitors with their tracks – arrows of bird’s feet and pads of rabbits and foxes in the orchard.
After the thaw, and an unreasonable and depressing amount of heavy rain, we surveyed the casualties. Leaves reduced to slime wreathed many plants, only one or two of the French lavenders, (Lavandula stoechas) survived. Some of the tender Australian shrubs such as the spider flower (Grevillea ‘Canberra Gem’) and the kerosene bush (Ozothamnus rosmarinifolia) had all their leaves burnt, suspected dead. Even some of the Euphorbias, usually a relatively robust genus suffered, and we fear we may have lost all the Sicily spurge (Euphorbia ceratocarpa), which are such incredible late-season pollinator feeders. This is part of our transitioning from horticulturalists to rewilding caretakers, to learn to let go of the idea of the garden as a static picture and embrace the boom-and-bust cycles of natural processes – to learn to look forward to seeing what might come and fill the gaps.
For most of the month, the largest ever conference on biodiversity was held in Montreal, Canada at COP15. All 195 participating countries came to agreement on the Kunming-Montreal Global Biodiversity Framework. It addresses the key drivers of nature loss and sets ambitious goals to halt and reverse the global decline in biodiversity. A welcome and positive note on which to finish the year, one which has seen climate change coming into sharper focus for all of us. It was difficult to keep up with the series of record firsts and superlatives when it came to temperature, winds, storms, rain, and snow in the UK. We have been lucky this year to welcome almost 500 visitors into the garden, from all different backgrounds and walks of life. We learnt so much in conversation, everyone contributing to the mixing pot of ideas and ways of meeting challenges. Our hope then, for 2023, to continue to converse and discover, and to see a steady, growing swell of positive action for nature recovery.
Moy Fierheller Deputy Head Gardener December 2022
Photos Suzi Turner, Charlie Harpur, Moy Fierheller
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