A shady area in your garden is a wonderful asset in the heat of summer. Modern gardens lack shade because many people are wary of planting large trees or are limited by restrictive covenants. The pleasure of sitting in cool, dappled light, under the natural umbrella of a generous shade tree, is thus denied. Even a small garden has space for one tree that will grow tall enough to sit under.
On a larger section consider using trees as nature’s air conditioners; plant deciduous trees on the northern and western side of your house to minimise the impact of the summer sun on your walls, windows and roof. Bare branches will not restrict the sun’s winter warmth. The free cooling your trees provide will be worth the annual task of clearing your spouting of fallen autumn leaves or installing permanent gutter protection.
Plants that are native to woodland areas are perfect for shady gardens. Choose a combination of foliage colours and textures. Include some that glow in shady places. Lime and yellow foliage creates the illusion of sunshine in shade. Variegated or shiny leaves and white flowers create light highlights in dark spaces. Do not try to grow lawn in heavily shaded areas. A better option is to lay a path surrounded by densely spaced, shade-loving ground-cover plants.
Large-leafed shade lovers
Large-leafed ground-cover plants that thrive in shade are hostas, bergenias and ligularias.
Hostas are beautiful deciduous plants, available in a wide range of leaf colours and forms, but sadly they are ‘ice-cream’ for snails. You will have to diligently control snails to achieve a glorious display. I highly recommend bergenia as a tough, low-maintenance plant that thrives in shade. It spreads slowly but if you lift plants every couple of years and replant the rooted rhizomes, about 300mm apart, they will cover the ground much faster.
Ligularias are also tough plants. The glossy large-leafed tractor seat plant (Ligularia reniformis) is an outstanding shade lover. Prone to wilting in dry conditions it will quickly revive when watered. Divide plants every few years. Smaller-leafed ligularias like the deciduous, dark-red leafed L. dentata ‘Britt-Marie Crawford’ or leopard plant, L. tussilaginea ‘Aureomaculata’ (syn. Farfugium japonicum ‘Aureomaculata’), with random yellow spots on its leaves are well worth considering.
The kaffir lily (Clivia miniata) is the perfect low-maintenance ground-cover plant in shaded frost-free areas. Their thick, glossy, strappy leaves and spectacular clusters of red, orange or yellow flowers and red berries glow under the canopy of evergreen or deciduous trees. In their native South Africa they thrive in the shade of a relative of our totara tree. They are slow to spread so lift and divide them every few years until you have sufficient plants.
Small-leafed creeping shade lovers
Smaller-leaved species with a creeping habit like Ajuga sp., Vinca minor ‘Illumination’, Lysimachia nummularia ‘Aurea’ thrive in shady situations.
Ajuga reptans (common bugle) is the green form of ajuga. It will quickly cover the ground in part shade forming a dense, weed suppressing mat with the added value of attractive blue flowers. Dark-leaved cultivars are also available. Vinca minor ‘Illumination’ forms a dense mat of dark-green-margined golden leaves with blue flowers. The lime-yellow foliage of Lysimachia nummularia ‘Aurea’ brightens dark areas and, if placed where it receives some sun each day, will turn butter-yellow. The creeping growth habit of these species means they will all need to be trimmed intermittently so they do not become invasive.
Pachysandra terminalis (Japanese spurge) forms a carpet of thick, attractively shaped leaves. It spreads by underground stems so weed out unwanted growth around its margins. Pulmonaria (lungwort) is valued for its attractive, clumping, silver speckled foliage and pretty pink and blue flowers. P. ‘Silver Bouquet’ is recommended for warmer areas being more tolerant of heat and humidity, and resistant to mildew than older varieties.
Every house has a heavily shaded area on its southern side. This space is ideal for a beautiful fernery. Many native and exotic ferns will thrive here as long as they receive sufficient water. Try the hen and chicken fern – Asplenium bulbiferum ‘Maori Princess’ syn. ‘Pacific Beauty’ is a superior form; Polystichum sp. are generally fairly easy to grow and cold hardy; Polystichum vestitum (prickly shield fern) is very cold hardy; Dryopteris erythrosora – Japanese Buckler fern – has copper-coloured new foliage and will tolerate a wide range of conditions; Doodia australis (syn. Blechnum parrisiae), common rasp fern, is an attractive colonising fern with bright pink new fronds; Athyrium niponicum var. pictum ‘Ursula’s Red’ the deciduous Japanese painted fern is a particularly beautiful fern with redtinged fronds. Keep ferns tidy by cutting off dead fronds. Ferns interspersed with clivia or ligularia is a lovely combination.
Winter roses are an easy-care, long-lived, winter-flowering ground cover, which flourish under deciduous trees. They have attractive leathery leaves and usually single flowers in shades of pink, maroon and cream which fade to green. A range of beautiful single- and double-flowered hybrids are available from a South Otago nursery. Keep them tidy by cutting off dead leaves. They prefer alkaline conditions and a sprinkle of dolomite lime will help prevent fungal attack, which they can be prone to in warmer districts.
Native rengarenga lily
Arthropodium cirratum is one of the best species to mass-plant in the dry shade of trees. Unfortunately its leaves often look ragged owing to the ravages of snails. It frequently features in the best designed gardens in Melbourne, where a designer told me feeding the plants generously in spring gives them a bitter taste that makes them less palatable to snails. A. cirratum ‘Matapouri Bay’ is a broadleafed cultivar with a larger flower head, but beware; it is even less tolerant of frost than the original species. I saw a large swathe of it badly affected by heavy frost in Auckland Botanic Gardens last winter, next to a group of the original species which was relatively undamaged.
Plant for success
To ensure successful planting in dry shade, use plenty of compost to improve the moisture-retaining quality of the soil. Lay a thick layer of fine bark mulch around new plants to retain moisture and discourage weeds. Make good use of your annual bounty of fallen leaves by composting them, or chop them by running your lawnmower over a pile of them. Spread the chopped leaves around your plants and leave them to decay in situ. Spread fertiliser to compensate for the nutrients tree roots remove from the soil. If the shade of your trees is too dense for plants to thrive, consider pruning them to allow more light and moisture to penetrate. To avoid permanent damage to a tree do not remove more than one third of its canopy in one season.
Shade in the garden is an asset to be appreciated in summer. Plant your shaded ground densely with a mix of contrasting textured and coloured, low-maintenance, shade-tolerant species so these spaces can be a joy throughout the year.