Solutions for shady, dry spots
Cape Town - Earlier this year, the UN General Assembly proclaimed March 21 as the International Day of Forests. With the slogan “Plant a tree, plant the future”, the day will celebrate and raise awareness of the importance of all types of forests.
For gardeners, planting up a garden with trees eventually requires knowledge of how to garden in the shade.
How do you deal with shade in the garden?
Start by appreciating that there are a number of different types of shade, some created by plants and others created by walls and buildings. To establish what kind of shade you have in your garden, stand underneath your trees on a sunny day and check how much sunlight comes through.
Dense shade is where no direct sunlight gets through the canopy to the ground. If rain is also restricted from reaching the soil, the combined conditions of dry and shady make growing plants very difficult.
Traditional advice for dry, dense shade has always been to plant non-invasive varieties of small-leafed variegated ivy (Hedera), peace-in-the-home (Helxine), strappy-leafed cast-iron plant (Aspidistra elatior), polka dot plant (Hypoestes), sterile varieties of the sword fern (Boston Gold) and indigenous asparagus fern (Asparagus densiflorus).
Dappled or filtered shade is created when sunlight filters through a canopy of small-leafed trees. A host of traditional shade plants are available for filtered shade, including azalea, forget-me-not, foxglove, fuchsia, coleus, hydrangea, fairy primula, anthurium and violets. If you prefer a more wildlife-friendly indigenous garden, use clivia, gebera, ferns, forest bell (Mackaya bella), tree fuchsia (Halleria lucida), plectranthus, pink polka-dot plant (Hypoestes) or the autumn-flowering lilac ribbon bush.
Semi-shade is defined as a situation when plants receive sunlight for a few hours a day, either in the morning or the afternoon.
Plants that grow well in morning sun include the white arum, asparagus fern, begonia, foxglove, fuchsia, gardenia and all the indigenous plectranthus species.
A few hours of afternoon sun in a very shady area is far harsher for plants to deal with, as the soil dries out very quickly. In these areas, try agapanthus, yesterday-today-and-tomorrow, crocosmia, day lily, gardenia and liriope.
These plants will tolerate hot, dry conditions, but their flowering may be stunted in some way if they receive only a burst of hot western afternoon sun for a few hours each afternoon.
When planting up a shady garden, appreciate that spacing plants further apart than you would in a sunny spot is recommended to improve air circulation and discourage mildew.
Flowering plants grown in shade tend to reach towards sunlight, and might need staking, whereas a host of foliage plants, with a variety of textures and shapes, will add interest to the garden.
Local environment-friendly gardeners are increasingly looking for an extended range of indigenous plants that can be used in the shade garden. Many of these plants are slowly becoming more known to gardeners, but most are still only available from the larger garden centres, indigenous nurseries or at plant fairs.
The Peninsula’s king of indigenous shade gardening is Kirstenbosch’s Ernst van Jaarsveld. For decades, he has advised gardeners which indigenous, and even endemic, plants are suited to dry, shady areas and narrow alleyways that never see the sun.
“Dry shade is probably the most common problem, and is usually found beneath trees and shrubs,” he says. “By choosing local indigenous plants to suit this situation, rather than battle against it, you will greatly reduce the amount of maintenance required to keep your garden thriving. And you will be working in harmony with nature, which means you will also make your garden more attractive to wildlife.”
One of the causes of dry conditions beneath trees is root competition between plants’ roots and trees’ surface roots.
Van Jaarsveld says: “Plants adapted to dry shade often feature large, leathery or succulent leaves, while smaller, ground-covering plants have fleshy roots or bulb scales.”
This enables them to compete successfully with tree roots for available water, and survive periods with no water.
“Many indigenous plants have adapted to tolerate both dryness and shady conditions. Plectranthus species have succulent leaves and grow in dry shade, such as the money plant (Plectranthus verticillatus). Agapanthus also grow in dry shade, but without enough light they unfortunately do not flower.
“Asparagus species have succulent root balls, hen-and-chickens (Chlorophytum species) and agapanthus have fleshy roots, the money plant or gossip (Plectranthus verticillatus) has fleshy leaves, and Drimiopsis maculata has a bulbous base.”
Indigenous shade-tolerant plants that survive root competition include the strelitzia, Crassula lactea, fairy crassula (Crassula multicava), Helichrysum petiolare, variegated plectranthus (Plectranthus madagascariensis), wild iris (Dietes grandiflora), Dracaena hookeriana, bush lily (Veltheimia), mother-in-law’s-tongue (Sansevieria aethiopica) and Senecio articulatus.
Other indigenous plants for planting under trees include the emerald fern, Clivia miniata, yellow wild iris (Dietes bicolor) and the cycad Encephalartos villosus. - Weekend Argus