For a moment, consider plants that are ordinarily recommended for shade gardens, such as azalea, calla lily and impatiens. In a garden of deep shade, none of these plants will grow well. They may look all right for a while and even put out a few flowers and fresh leaves for a short time. But soon enough their stems will become leggy; that is, their stems will elongate unnaturally as a result of light deprivation. Flowering will cease. Ferns, another group of plants recommended for shade, also require a generous amount of ambient, indirect or filtered sunlight to flourish.
Enter a robust group of plants for deep shade that dare to thrive where classic so-called shade lovers founder. All of these deep-shade dwellers, predictably, made their reputation as indoor plants. Low light conditions indoors replicate the low light conditions of the tropical forest, which happens to be the habitat of plants for deep shade.
The kentia palm (Howea Forsterana) is especially suited to deep-shade conditions. So is the bamboo palm (Chamaedorea Seifrizii) and, if you can afford it, the lady palm (Rhapis excelsa). The best shrub for deep shade is the Hawaiian elf schefflera (Schefflera arboricola), a popular house plant with mini-umbrella leaves. Mother-in-law’s tongue (Sansevieria) is a shade-dwelling plant whose vertical lines contrast nicely with the bushy schefflera. Seek out the elegant black and green marbled mother-in-law’s tongue; it is far easier on the eyes than the ubiquitous yellow-margined variety.
Some gardeners pale at the thought of planting what are usually potted indoor plants in the ground outside. Greater attention than usual should be paid to the soil, which must drain well to satisfy the requirements of these tropicals. Another concern is protection from cold and, in truth, it would be better not to make a shade garden of these tropicals in the Antelope or Santa Clarita valleys. But I have seen all of them growing well in the San Fernando Valley, where overhead protection was provided by tall trees. In fact, the deeper the shade, the warmer the location, since heat absorbed by the ground during the day cannot escape to the sky at night, being trapped by the foliage.
For average to deep shade conditions, some of the best selections are plants with variegated foliage. Shade-tolerant plants with white, cream or yellow markings on their leaves will light up the dark corners of your garden. Where yellow- or gold-splashed foliage is sought, no plant is better for the shade than the so-called gold dust plant (Aucuba japonica). There are two main types available, showing either tiny gold sprinkles or large gold splotches on the leaves. Another popular gold-flecked plant for shade is the variegated Chinese lantern (Abutilon pictum “Thompsonii”), as is the variegated schefflera.
Glacier ivy is a popular ground cover for the shade. Its leaves blend various shades of white, cream and green together. It is not nearly as invasive as other ivies. Ground ivy (Glechoma hederacea “Variegata”) is not a true ivy but rather a mounding and trailing, delicately leafed ground cover. Variegated lily turfs, especially Liriope muscari “Silver Queen,” are used successfully as edging plants in long, shady borders.
The workhorse of the shade garden is Pittosporum Tobira “Variegata,” a robust shrub also at home in the sun. Because of its wide adaptability, it can tie diverse areas of a landscape together. It does well either as a background hedge or as a stand-alone subject under trees. Its creme- de-menthe leaves allow it to blend well with nearly any selection of plants.
TIP: When planting a shade garden, consider what the sun and shade conditions are going to be throughout the year. Although sunlight may be scarce in winter or even early spring, it could be overly abundant in summer.