The Journey to Wilding the Garden ~ February 2022

The drab hues of winter are finally starting to change, the ground spangled with small flashes of colour. Under the oaks, purple crocuses are primed to unfurl, snowdrops are almost ready to drop their heads, the Christmas box is in full-scented starburst, and the jolly, pale-yellow faces of primulas jostle for space. The new planting in Tom Stuart Smith’s design in the Pool Garden is bringing another layer of late winter interest, the acid yellow buds of the upright spurge (Euphorbia rigida) standing sentinel above its grey spirals of foliage – a striking contrast to the blood-red leaves of emerging Paeonia cambessedesii. This early flowering deep-pink peony is native to the north of the island of Majorca, found on limestone ridges, suiting the nutrient-poor, free-draining nature of the mounds and slopes of sand and crushed concrete mixes in the garden. Sadly, it is now considered endangered due to habitat loss from grazing sheep and goats, so we are very excited to have the opportunity to grow it here. 

Most of the new plants seem to have escaped damage from the intermittent frosty mornings, but the older rock roses (Cistus ‘Alan Fradd’ and Cistus ladanifer) that run along the wall of Old Acacia Walk had suffered. Running parallel to the wall is the long beech hedge, cut to Tom’s design into an irregular undulating wave. The natural process of the behaviour of frost is fascinating to see reflected in the scorching of the Cistus leaves, exactly mirroring the line of the hedge where it dips, showing where the direction of the frost has continued unimpeded, literally hitting a brick wall and coming to rest on the plant. Horticulturally, we know that keeping top growth lightly pruned stops the plant from getting too leggy and increases flowering, the practice no doubt evolving from observing its response to the natural process of recovery from frost damage, as well as seeing a similar consequence from the action of browsing herbivores.

On the other end of the scale, we were interested to see how the new planting in the Pool Garden was faring below ground. Clearly many of the plants have established well, already putting on some growth since planting in mid-November last year. Having spent time in the last few years looking at soil health and its complex world of fungi and microorganisms, one of our questions was how these entities might behave in the sand and concrete. In soil, the presence of rhizosheaths are a sign of biological activity, where aggregate soil particles form around the root zone (rhizosphere), bound together by the secretions of microorganisms. Rhizosheaths can help plants withstand water stress and nutrient deficiencies, although plants from the brassica, allium and asparagus families do not develop them. When a plant releases excess sugars the fungi and microorganisms are fed and they, in turn, process nutrients into a form that the plant can take up.  Despite our rudimentary understanding of these complicated systems, we were both surprised and pleased to observe the roots of the golden oat (Stipa gigantea), not only had a healthy amount of new growth, but they were also generously coated in sand particles, suggesting at least some form of binding is taking place.

The rhizosheath of Stipa gigantea

We have been following the work of John Little who specialises in designing public spaces using various aggregate planting mediums – essentially construction waste – with an emphasis on creating wildlife habitat. There is a focus on structure – everything from the spaces and voids between materials large and small that can provide all manner of diverse services to wildlife, to cool and moist hiding-holes at the base of slopes and warm, dry, dark cavities on larger rocky ridgelines. There seems to be a tendency to think of rocky, sandy environments as sterile or hostile but the more time we spend in this garden the more we learn about the opportunities and diversity it presents.

The garden’s resilience was put to the test as Storm Eunice swept across the southeast on 18 February, with veteran trees wrenched from the soil, fences and garden furniture flying into the air. Wind speeds reaching a high of 122mph at the Needles in the Isle of Wight left a swathe of devastation and the somber news of four fatalities. In the garden there was remarkably little damage. A few of the smaller bare-rooted grasses had become dislodged from the more sandy areas, the thatched hat that sits on top of the natural beehive had blown off, and the pencil cypresses lost a few of their limbs but the rest of the inhabitants survived relatively unscathed.

Although the cold winds continued, the winter pruning of the apple trees in the orchard needed addressing while the trees were in their dormant period.  The sun intermittently showed its face and blue skies appeared, and with the help of some of our fantastic garden volunteers we set to work. We wanted to clear the centre of the trees of upright, crowding water shoots, tip out last year’s new growth to encourage more fruiting buds and take out any dead limbs or those that showed signs of damage or disease. Like all traditional age-old pursuits, the feeling of community with people and nature conveyed a wonderful sense of calm and pleasure.

Garden volunteers winter-pruning the apple trees

By covert agreement wild cherry blossom explodes simultaneously everywhere we look in the last week of February, delicate sprays of pink and white petals, with stamens protruding ready to welcome early foraging honeybees. Buff-tailed bumble bees (Bombus terrestris) have active nests during the winter, feeding on snowdrops and winter viburnum (Viburnum bodnantense) in the garden, the foraging queens wonderfully large and noisy.  It was fantastic to spot an early emerging red admiral butterfly on the scented pink Viburnum flowers. Common in almost any habitat the population both overwinter in the UK as well as migrate northward through spring and summer from North Africa and Europe. The orchard and the wider landscape provide a plentiful food source for their caterpillars, their preferred sustenance being nettles, while the adults forage nectar from buddleia and ivy flowers. For the RSPB’s annual Big Garden Birdwatch day Cathy Wallace, Knepp’s social media manager, kindly offered an hour in the garden and noted blackbirds, robins, great tits, blue tits and long-tailed tits. The sense of life emerging, nature waking, growing and changing is reassuring in these turbulent times, an ever-present reminder of its importance in our lives and the pressing needs of its protection and restoration.

Moy Fierheller     Deputy Head Gardener    February 2022

What we’re reading:

The Rhizosphere – Roots, Soil and Everything In Between | Learn Science at Scitable (nature.com)

 The rhizosheath: a potential root trait helping plants to tolerate drought stress | SpringerLink

Effect of root exudates and bacterial metabolic activity on conjugal gene transfer in the rhizosphere of a marsh plant | FEMS Microbiology Ecology | Oxford Academic (oup.com)           

John Little Grass Roof Company 

Is fly-tipping good for biodiversity? The importance of complexity in new landscape design – Bing video