Most gardens have shaded areas and most gardeners find them challenging situations. Often favourite flowering plants fail to thrive, results are disappointing and failure leads to greater despondency about the shaded areas of the garden. Small gardens in urban areas often have more than their fair share of shade from neighbouring buildings, walls and fences. Large country gardens may have shade from mature trees and hedgerows. The amount of shade varies with the time of day and the time of the year. Confusion is made greater with a plethora of terms for different types of shade: partial shade, semi-shade, deep shade, light shade, dappled shade and so on. So what do they all mean? Are there hard and fast rules? As with everything in gardening the answer is no; however I may be able to give you a guide based on my understanding. Just to reassure you I will say you will not be disappointed by the amazing range of plants that will grow happily in shade.
At the outset I will say that most flowering shrubs and perennials will grow and bloom satisfactorily with four hours of direct sunlight, as long as this is in the middle of the day and for most of the main growing season. Foliage shrubs with golden or purple leaves will also retain good leaf colour in these conditions. Real sun lovers such as lavender, cistus, silver foliage shrubs and sun loving perennials will normally be more successful with six hours or more of direct sunlight in the growing season. Many bulbs, corms and tubers grow and bloom happily with relatively little direct sunlight; subjects like Cyclamen hederefolium are well adapted to woodland conditions.
What is partial shade or semi-shade? In these conditions the planting site will get between two and four hours of direct sunlight each day. For the rest of the time neighbouring plants or buildings cast a shadow over the area. These hours of direct light could be in the morning or late afternoon, however they will be more effective between the hours of 10 and 3, when the sun is overhead.
What is light shade or dappled shade? Dappled shade occurs under the light canopy of trees such as birches. Spots of direct sunlight get through the canopy, but they change and move around. Dappled shade is usually a good growing condition for those plants that are adapted to woodland conditions; where direct sunlight might all be too much in the height of summer. You could refer to the same conditions as light shade, however I consider this also to refer to shaded areas that receive lots of reflected light. This could be reflected to the area by a light coloured neighbouring wall or a glass window. This is common in small courtyard gardens which often receive little in way of direct sunlight. Low growing evergreens such as sarcococca are excellent in these conditions. They retain their deep green leaf colour and shiny leaves reflect the light.
What about heavy shade or deep shade? This occurs where there are overhanging trees or structures that cast a permanent shadow and there is little if any reflected light, The soil is often dry leading to dry shade: the most challenging of growing conditions.
The growing conditions in a garden often change as the garden matures. As trees and shrubs grow they have had a major effect on the growing environment. Beds that were once in full sun may now be quite shady.
So which plants grow well in shade? Once you get used to selecting plants for shade you will realise what a vast range of plants will grow in shady conditions. Shade is only a problem if you insist on planting sun lovers. I always encourage gardeners to think of foliage first when choosing plants for shade; usually foliage colour from variegated leaves is more reliable than colour from flowers. Even golden leaved evergreens such as Choisya ‘Sundance’ can work really well in shade. Although it loses its bright yellow colour it stays bright lime-green and really lifts a shady spot. Personally I prefer it that way.
Variegated evergreens such as varieties of Euonymus fortunei and Euonymus japonicus are reliable favourites for all types of shade. The green and variegated forms of Buxus sempervirens are successful, hence their prevalence in town gardens. Variegated ivies are equally happy in shade. It is a shame that they are often shunned through fear of damage to brickwork and masonry. Variegated and green leaved varieties, such as Vinca minor ‘La Grave’ make colourful ground cover in shade with the benefit of spring and summer flowers.
Some plants will surprise you. Take the spiky-leaved silver Astelia ‘Silver Shadow. Because it looks like it needs sun that’s where it often ends up in the garden. Actually it likes partial shade because of its origin in Australian woodlands.
So what about flowering shrubs and perennials in shade? Camellia japonica and Camellia x williamsii varietiesare both good choices for shade. Their spectacular winter and spring flowers are best kept away from the morning sun and are less damaged by frost in these conditions. They do not flower well in heavy shade but with a couple of hours of direct light a day they put on a splendid show. Pieris, the lily-of-the-valley bush produces its delicate racemes of flowers in partial or light shade . Most varieties also have colourful new growth and some, such as Pieris japonica ‘Ralto’ have variegated leaves which add further colour and interest. Pieris and camellias make excellent long-term subjects for pots in shade.
Ferns are also good in pots and containers, as are carex, ornamental varieties of sedge. These could be grouped together with evergreen epimediums and heucherellas. The latter are better in shade than heucheras and add interesting leaf forms and patterns.
In shady corners and under trees the pulmonarias, lungworts provide both spring flower colour and often spotted or marbled foliage. They make good planting partners for spring flowering bulbs such as dwarf narcissi which can add a real blast of colour to a scheme that is quieter for the rest of the year.
Other good choices for shady situations include:
Leucothoe fontaiseana ‘Rainbow’
Helleborus x hybridus