Pollarding trees
Catalpa bignonioides ‘Aurea’ showing fresh growth in May after pollarding in STUMPS TO early spring.
Cutting o the main stem RHS / TIM SANDALL of a tree may seem like horticultural vandalism, but pollarding the right plant produces dramatic e ects stars Catalpa Author: Ian Tocher, RHS Trials Indian bean trees become more shrubby when Team Horticulturist Sambucus pollarded, with large, strongly coloured foliage. Elders respond well to pollarding, becoming smaller, ✤ Selections to choose: catalpas are trees, ollarding is an ancient pruning technique, more-upright plants, with larger, lush, better-coloured lowering in late summer, with long, decorative used from prehistoric times to produce wood foliage, often elegantly dissected, depending on cultivar. bean-like pods. When pollarded, these features and fodder. Certain trees, such as willow and ✤ Selections to choose: although often regarded as are lost, but the larger leaves gained thereby are impressive. Golden Catalpa bignonioides ‘Aurea’ ash, were decapitated at about 2m (6½ft) tall; shrubby weeds, there are some highly ornamental will provide strong contrast with surrounding the new shoots that sprouted, above the reach Sambucus (elder) with purple or gold foliage. One good example is Sambucus nigra f. porphyrophylla ‘Eva’, herbaceous plants. Its foliage is e ective with Pof browsing animals, were harvested every few years. Echinops bannaticus ‘Taplow Blue’, iery red with its dark, lacily dissected foliage. Elegant ‘Guincho Pollarding is diff erent from coppicing, which requires Purple’, named after Guincho Gardens in Co. Down, crocosmia and Geranium palmatum. Purple the plants to be cut down to ground level. Nowadays Northern Ireland, has bolder, bronze-purple dissected Catalpa x erubescens ‘Purpurea’ (inset), with RHS many ornamental trees and shrubs are pollarded to / new leaves that are almost black, is foliage followed in summer by unusual tufts of bright GR AH A create spectacular decorative eff ects, including larger M dramatic alongside iery- lowered green leaves. Its lower petals are tinged pink, although T IT C herbaceous plants. leaves and lush, brightly coloured foliage. As well as lowering with all selections is reduced if pollarded. For H M A producing interesting new growth, this technique dazzling gold foliage, try S. racemosa ‘Sutherland Gold’. R ✤ Use and how to grow: S H restricts the plants’ size, which means they can be ✤ Use and how to grow: kept as a pollard, these plants pollard in late winter to around grown in smaller spaces. produce lush foliage. Bronzy-purple selections look 0.5m–1.5m (1½–5ft). Cut back the RHS Garden Wisley’s famous Mixed Borders make great with red- lowered herbaceous plants, such as new growth each following spring to within a few good use of pollarded trees and shrubs. ere, Catalpa, monarda and Lychnis chalcedonica. Once the shrub is centimetres of the pollarded Paulownia and Sambucus act as foils for showy established, cut back its branches in March to a central Pollarding Catalpa stems. Plant in any well-drained herbaceous plants while also providing height and framework at the required height. Each following spring cut new shoots back to within a few centimetres of the bignonioides ‘Aurea’ makes it soil, ideally deep, moist loam. They structure. In summer, intense acid-yellow Catalpa leaves suitable for a mixed border. like a sunny, sheltered spot.
previous year’s growth. Grow in full sun for the best BORKOWSKI ELKE / GAP contrast with vivid blue delphiniums. Even in winter, colour, but also suits partial shade. when the border is largely dormant, the gnarled, twisted stems of the pollarded Paulownia provide interest. Making the cut Populus It is best to pollard young trees or shrubs rather than Pollarded poplars produce vigorous shoots with older specimens. Establish plants in a suitable location larger leaves and good colour. for around three years before cutting. In late winter or ✤ Selections to choose: when pollarded, unusual Populus early spring use a sharp pruning saw to cut across the deltoides ‘Purple Tower’ produces new shoots with large, main stem (or stems) at a suitable height – anywhere glossy, red to deep purple leaves on red stems speckled between 0.5–2m (1½–6½ft). Taller pollards are useful with beige. The leaves also have beautiful red veins when young and provide good autumn colour. They are at the back of a border. Angle the cut slightly to disperse particularly e ective when combined with silver- LL DA water from the stem, and remove any lower sideshoots. N leaved shrubs. Gold-leaved Populus alba A S New growth will sprout from near the pruning point. IM ‘Richardii’ can also be pollarded; its foliage T / S Not all deciduous trees and shrubs are suitable for H is smaller but the yellow leaves have a R pollarding. Choose those having good disease resistance silvery underside. Plants may sucker. TGC / FP / NOVA PHOTO GRAPHIK and high vigour, which are thus able to cope with regular ✤ Use and how to grow: these plants pruning. Once trees have been pollarded, continue like full sun or partial shade and prefer doing so annually, or at least every few years. Pollarded moist conditions but can tolerate
trees left unpruned for any length of time can produce CLIVE NICHOLS dry soils. Plants have vigorous roots: overlong, weak and potentially dangerous stems. do not plant by houses or drains. Sambucus nigra Sambucus racemosa Here are profi les of fi ve plants with ornamental Once established, pollard yearly in Populus alba f. porphyrophylla ‘Eva’ ‘Sutherland Gold’ spring, to around 0.5 1.5m (1½–5ft). ‘Richardii’ Populus deltoides ‘Purple Tower’ foliage suitable for pollarding, and on p56 are some JAMES ADRIAN / GWI further plant suggestions to try.£ »
54 The Garden | October 2016 October 2016 | The Garden 55 Pollarding trees More plants to pollard
Toona sinensis ‘Flamingo’ Tree with vibrant pink spring foliage; pollarded plants kept compact for use in borders. Do not cut until well established.
Liriodendron tulipifera ‘Aureomarginatum’ Once established, tulip trees can be pollarded, to make the most of Paulownia their unusually shaped tomentosa leaves close to eye level. Pollarded foxglove trees have vast leaves on vigorous shoots. Acer negundo ‘Kelly’s Gold’ ✤ Use: After pollarding, fast- Pollarding ensures this growing Paulownia tomentosa tree’s dazzling leaf will produce leaves up to 60cm colour is seen to best (24in) across and new stems advantage. Foliage 2.5m (8ft) or more high. Great and growth remains for architectural structure ANDREA JONES / GARDEN PHOTO EXPOSURES LIBRARY fairly compact. and exotic plantings. ✤ How to grow: choose a sheltered position in sun Cotinus coggygria or partial shade in deep, rich, ‘Royal Purple’ well-drained soil. Cut stems By pollarding this to the required height; prune vigorous shrub the new growth each spring to overall plant size within a few centimetres of is reduced, while lush, the original cuts. larger-leaved, richly coloured shoots abound.
Tilia tomentosa Pollarded, this tree can be grown as a shrub Eucalyptus with large, green, Pollarding gum trees restricts their size heart-shaped leaves, and encourages fresh, juvenile foliage. silvery beneath, and fewer of its scented ✤ Use: Eucalyptus gunnii can grow to lowers, narcotic to bees. 30m (100ft) in their native Tasmania, but pollarding produces shorter plants with distinctive, rounded, blue juvenile Others to try leaves, then narrower mature leaves. Some trees and shrubs worth Plantsman Christopher Lloyd (see p19) considering for pollarding include:
used it with purple Cotinus coggygria ✤ Acer negundo ‘Flamingo’ RHS / TIM SANDALL, CAROL SHEPPARD and berberis to spectacular e ect. ✤
GAP / JONATHAN BUCKLEY Acer pensylvanicum ‘Erythrocladum’ Other species can also be pollarded. ✤ Ailanthus altissima (may sucker) ✤ How to grow: eucalyptus will grow ✤ Aralia elata in most soils. They like full sun but not ✤ Cercis siliquastrum strong cold winds. Pollard in late spring ✤ Corylus maxima ‘Purpurea’ to around 45cm (1½ft), then prune ✤ Eucalyptus globulus (tender) each following spring. ✤ Liquidambar styraciflua ‘Worplesdon’ ✤ Populus x jackii ‘Aurora’ (may sucker)
56 The Garden | October 2016