Garden Design (2015)

Exotic planting

A bold curve of exotic-looking daylilies sweeps past a backdrop of hardy Chusan palms (Trachycarpus) and cabbage palms (Cordyline australis).

DESIGN BY ACRES WILD

BOLD FOLIAGE and bright flowers are the signature ingredients of an exotic or tropical planting style, but while the traditional plants used to evoke this look were tender treasures unable to withstand cold winters, new forms are making it more manageable in cool climes.

Cool tropicals

Wherever we are in the world, many of us like to include plantings that remind us of home or of a memorable holiday or experience. For those living in cool, temperate climates, such as Western Europe, the lure of exotic and tropical-style planting, with dramatic palm trees and large-leaved shrubs, spiced with vibrantly coloured flowers, is a beguiling and increasingly popular proposition. Gardeners in these cooler climes can choose from a variety of plants that will express this unfettered lushness. In recent years, introductions from higher altitudes in tropical and sub-tropical regions has resulted in a greater number of plants, including Tetrapanax papyrifer ‘Rex’ and the banana, Musa basjoo, that will tolerate lower winter temperatures. A warming climate and the urban heat-island effect of towns and cities, which raises ambient temperatures, has also allowed plants that are normally thought of as tender to thrive in British gardens.

“A huge spectrum of colours are found in the tropics but when designing at home, try a large dollop of bright orange, red, and hot pink. Kniphofia ‘Nobilis’, Crocosmia ‘Spitfire’ and Hemerocallis ‘Stafford’ are all good hardy candidates. Try these against a green leafy backdrop of bananas (Musa basjoo) and euphorbia.”

LUCY SOMMERS

Exotics for all seasons

The exotic planting style reaches a peak during the summer months when tender plants and flowers, including Canna and Dahlia are in full bloom. Spring colour can be introduced with ferns, such as Matteuccia struthiopteris, and Zantedeschia aethiopica, while Hedychium gardnerianum and Nerine bowdenii will contribute late autumn interest, when some of the tenderest plants will already be under cover. To avoid a blank canvas in winter, include some hardy evergreens, such as ferns, and structural trees and shrubs, such as the Indian bean tree Catalpa bignonioides, Magnolia grandiflora and Aralia, together with the Chusan palm, Trachycarpus fortunei, which all have bold foliage that lends itself to this style. Hardy perennials, such as the exotic-looking daylily Hemerocallis and Crocosmia add floral piquancy in summer, and leafy plants, including hostas, Fatsia, and Farfugium japonicum, which can be used to create a lush understorey, add an exotic flavour while sailing through cold winters outside.

ANNUAL INJECTIONS

Bedding dahlias, amaranthus, coleus and gazanias all sport brightly coloured flowers that lend a tropical note to planting schemes, and are easy to grow from seed sown indoors in spring. Sow from March in seed trays or pots of seed compost undercover in a greenhouse or on a windowsill. Transplant the young seedlings and grow on in 7.5cm (3in) pots. Harden off in a cold frame, or set outside during the daytime for a couple of weeks, before planting outdoors after the danger of frost has passed. Purchase bulbs, such as cannas and tender calla lilies, from seed merchants and grow on in pots, planting out as for the annuals above. Alternatively, buy young or semi-mature plants from garden centres.

Key tropical-style plants

Alstroemeria varieties; Arundo donax; Canna varieties; Catalpa bignonioides ‘Aurea’; Dahlia varieties, especially Bishop series; Dicksonia antarctica; Echium pininana; Eriobotrya japonica; Eucomis bicolor and E. comosa; Hedychium species and varieties; Hemerocallis, especially large gaudy hybrids; Fatsia japonica; Lobelia tupa; Melianthus major; Miscanthus sacchariflorus; Musa basjoo and M.sikkimensis; Paulownia tomentosa; Phormium species and varieties; Phyllostachys species; Ricinus communis; Tetrapanax papyrifer; Trachycarpus fortunei; Verbena bonariensis; Yucca species and varieties, Zantedeschia species and hybrids

CULTIVATION NOTES

For gardeners in areas that experience sub-zero temperatures and cold, wet winters, this style will require high levels of maintenance, as many of the plants used must be covered or brought inside over winter. Some tender plants, particularly succulents, will tolerate freezing conditions if their roots are kept dry or if they can regenerate from bulbs and rootstocks below ground.

Tender and exotic plants need good soil conditions, but they range in light requirements, from full sun to shade, depending on species or variety. Cannas and dahlias prefer sun, while begonias and tree ferns, together with other plants hailing from jungle environments, are happiest in shade.

To minimise the risk of losing borderline hardy plants in winter, cover the crowns of tree ferns and palms with insulating material, such as dry straw covered with horticultural fleece. Also mulch plants such as dahlias and hardy bananas with a thick layer of bark chips or other material to protect them from penetrating frosts; remove the mulch once the danger has passed and plants start to regrow in spring. Growing tender plants in pots makes the job of moving them in and out of the greenhouse easier too.

Prune back the shoots of an established foxglove tree, Paulownia tomentosa, to the ground (known as stooling) each spring, and the luxuriant new growth will sprout larger leaves.

Hardier bananas, such as Musa basjoo, can survive mild winters in a sheltered spot and, when adequately protected, will reshoot in late spring.

DESIGN BY AMANDA PATTON

Hardy bananas, honey-scented Euphorbia mellifera, scarlet-flowered Crocosmia ‘Lucifer’ and Arbutus x andrachnoides create a luxuriant jungle in a town garden.

DESIGN BY LUCY SOMMERS

Large-leaved shrub Tetrapanax papyrifer ‘Rex’ (far right) sets the right tone among exotic-style perennials such as Persicaria, orange dahlias and vivid crocosmia.

DESIGN BY JULIA FOGG

Late-flowering red hot poker Kniphofia rooperi makes an imposing display against a screaming scarlet dahlia.

DESIGN BY SUE TOWNSEND

Ivy-clad fences, a green-roof and extensive use of bold foliage transform this narrow, shady garden into a lush, leafy retreat.

DESIGN BY CLEVE WEST

A lush, secluded enclave in a shady nook is enhanced through the careful positioning of tree ferns and a textural underplanting of shade plants.

DESIGN BY PATRICIA FOX

Pared-down planting in a shady corner radiates cool charm. Tree ferns are underplanted with deciduous Hakonechloa grass and clipped globes of evergreen box.

DESIGN BY TOM STUART-SMITH