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| All pictures: Nigel Dunnett |
Perennials have dominated the movement towards a more naturalistic approach to planting design: the so-called ‘new naturalism’ has focused almost exclusively on herbaceous plants to create beautiful evocations of nature. Taking inspiration from the most spectacular flowering landscapes and plant communities around the world, it is hardly surprising that designers have focused on diverse grassland types such as prairies, meadows and steppe as their starting point. Shrubs and other woody plants have been left out of the equation.
Shrubs, in particular, have missed out for several reasons. Firstly, the perennial movement was a direct reaction against the previous shrub-based regime, whether it was the stodgy ‘shrubbery’ of the British garden, or the widespread use of monotonous ‘shrub-mass’ plantings in the public landscape, shrubs became a no-go area for the new designers. Perennials presented dynamism, colour, and change, compared to the rigidness of the typical tired shrub. But the name doesn’t help either: ‘shrub’ lacks a certain sexiness, and the American equivalent, ‘bush’, isn’t much better. Perhaps we should use the wider American term of ‘woody’ as opposed to ‘herbaceous’. Let’s hear it for the Woodies!
So, how can we use woody plants in the new naturalism? Naturalistic planting design takes ‘natural’ plant communities and vegetation types, and uses them as the base for creating enhanced, ‘pepped-up’ versions for gardens and designed landscapes. So what are the woody starting points for shrubs? Three ‘natural’ models spring to mind to begin with, and immediately, again, we are not helped by the terminology! ‘Scrub’ is the very unflattering name given to the often magical mix of scattered shrubs and small trees amongst meadow or grassland, so typical, for example, of chalk or limestone areas, and a veritable biodiversity hotspot for birds and insects as well as plant life. ‘Woodland Edge’ is an obvious one, and particularly on sunny, south-facing edges can be a bounteous mix of flowering and fruiting shrubs and vines, mixed with woodland perennials, and often merging into meadow grassland. And then we have the coppiced woodland, where trees are turned into multi-stemmed shrubs, promoting sparkling mixes of spring flowers and ferns to grow beneath.
So, there are some reference points. How do we apply them in planted landscapes? The answer is straight-forward: use exactly the same principles that have been applied to perennials now for decades. Take the reference plant communities; think about their structure and form and dynamics; pick a range of key species that fit that structure, whether native or non-native; and, crucially, keep it simple to begin with. Avoid the horticultural temptation of using as many different species and cultivars as possible, and instead use a limited number of well-chosen species. It often pays to use only one to three different shrubs for example, and maybe up to ten perennials and grasses. Repeat that limited number of key species again and again within the planting to build up the drama of rhythm and pattern. With the woodies, it is also very important to think in layers: the ground layer of perennials, bulbs, annuals; as well as the woody component.
Here are a few examples taken from plantings in Sheffield where I have used woody plants with perennials in a dynamic, naturalistic approach - they include Coppice with Amelanchier Coppice with Geraniums; Coppice with Hazel and Oxlips; Forsythia Woodland Edge; and Prairie Scrub.
Amelanchier Coppice with Geraniums, Sheffield General Cemetery
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| Amelanchiers spaced one to two metres apart, with perennials beneath |
This planting has been established for five years. Around 15 multi-stem Amelanchier canadensis are planted closely in groups, but at irregular intervals, between one and two metres apart. Beneath is a perennial layer with hardy Geraniums (G.phaeum, G.magnificum, G.macrorrhizum, G.sylvaticum), Polygonum bistorta, Male Fern, Primroses, and in the more open areas between the Amelanchiers, Rudbeckia fulgida var deammii, and Aster divaricatus, for later in the summer. The mass planting of Amelanchiers has been extraordinary in blossom this spring, and they will give an equal autumn display as they flare up in organge and red. In the months between, the perennials beneath and around take up the slack. The Amelanchiers are coppiced (cut to ground level) every three to five years: this rejuvenates the shrubs, and keeps them small enough to allow the perennials to thrive beneath.
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| Only one shrub species is used, but repeated through the planting |
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| The Amelanchiers can be coppiced (cut to ground level) every three-five years |
Hazel Coppice with Oxlips, Sheffield Botanical Gardens
This area has been established for seven years. Native Hazels were planted as whips at a distance of 2 metres apart. A mass planting of Oxlip (Primula elatoir) was established between – each primula was spaced at 30 cm. Also in the mix were primroses, Anemone blanda, and a scattering of vivid red/pink Corydalis solida. In the intervening years, the oxlips have self-seeded freely, forming a complete carpet. The hazels are now substantial, and are coppiced regularly – one or two in the planting are cut back each year, and left to grow on for four or five years before being coppiced again.
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| A coppiced hazel in the foreground - this will quickly regrow |
Woodland Edge with Forysthia, Sheffield General Cemetery.
Woodland edges mark the transition between the dark woodland interior and the sunny expanses of meadow in a natural landscape. As a typical 'ecotone', they can contain the best of both worlds: dramatic flowering and fruiting shrubs, and perennials both of meadow and half-shady places. Many shrubs typically grown in gardens come from woodland edge habitats in the wild. For example, here I used a long strip of the much maligned Forsythia as a woodland edge plant. Forsythias have such a bad reputation largely because of the way they are used, not for what they are. Here, in March and April, the boundary to this area lights up as a strip of gold, but then recedes when in leave to become part of the background - indistinguishable from native woodland edge shrubs. The meadow in front is a 'hybrid' native-non-native sown meadow, with native species such as Oxe-eye Daisy and Greater Knapweed, together with garden plants such as Aquilegia hybrids for the late spring.
It doesn't take much more imagination to imagine the forsythia woodland edge underplanted with masses of blue scillas to create an unforgettable spring combination. Similar 'suburban' shrubs could be used - the flowering currant for example. But on its own as the main woodland edge shrub - not with the forsythia! Pink and red currants underplanted with white narcissus? Or lilacs? All of these shrubs flare up for spring and then merge with the general woodland edge for the summer. Mix with scrambling roses, honeysuckles and a host of other things, and we have a mixed native-exotic woodland edge that is the direct counterpart of the mixed native-exotic meadow.
Prairie Edge with Rhus
This was my earliest foray into dynamic shrubbery! Taking inspiration from the spectacular roadsides and scrubby areas of the eastern United States, and the edges of prairie grassland, where the perennials and grasses merge into patches of scrub and woodland to create firework displays in the fall, I planted Rhus typhina amongst Rudbeckias in meadow grassland. The intention was for the shrubs to colour-up at the same time as the Rudbeckias were in flower. The rhus were coppiced to prevent them becoming huge. The Sumach is another of those shrubs that many people fear because of its suckering habit, but when used as part of a dynamic planting, that becomes a postitive asset - new shoots appearing spontaneously amongst the perennials.
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| Rhus typina growing wild on a roadside in North Carolina |
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| Planted 'Prairie Scrub' |
