May 07, 2011
FROM LATE FEBRUARY through April, my shady, Japanese-style garden is brimming with color. Each year I am astonished by the hazy cloud of new pink and pale green leaves of the maples, especially on clear days, when their color is contrasted against the blue of the sky.
Beneath this gentle, evolving leafy canopy, azaleas, camellias and a dwarf cherry all bloom at once, their flowers contrasting with the stolid, reliable green of ground covers, evergreen shrubs and ferns. At the end of the garden, a violet wisteria is in bud, ready to explode. In a few weeks, my bright red rhododendron takes over to keep the show going a little longer.
In summer, this garden reverts to its more sedate self, becoming a primary trio of maples, shrubs and ferns in various textures and shades of green. Most of the shrubs are small leaved and pruned to be relatively compact, in keeping with the Japanese character of the garden. The maples provide filtered or dappled shade, with sun-filled bright spots that are surprisingly dramatic, constantly changing the intensity of the garden's basic green.
In summer, a ground cover of blue star creeper (isotoma fluviatilis) covers the open spaces with a carpet of pale blue, which lasts for three to four months before we cut it back. For bright spots of contrast I like hakone, a deciduous grass that is bare in winter but has striking pale green, variegated foliage the rest of the year.
At the garden's edge a patch of armeria blooms most of the year except in winter. Its dainty pink flowers float on 6-inch stems above a dark green, grasslike base that fits in nicely.
Most gardens are a combination of a variety of flowering annuals, perennials, trees and vines, possibly including a kitchen garden of fruits and vegetables. This kind of garden requires good sun, preferably year-round, which I don't have. My choice of a shady garden was an effort to comply with existing terrain and climate rather than fight it. It has turned out well, and in the process I've learned a lot about gardening in the shade.
Not all trees are suitable for shady gardens. I'm partial to deciduous trees because they allow winter sun to penetrate the garden, which might otherwise be damp and gloomy. Be wary of very tall trees or widely spreading trees, unless you have lots of space. They will be harder to
prune and shape. A recommended few: Japanese maple, golden rain tree, crabapple (malus floribunda). I'm willing to rake fallen leaves in exchange for the glory of their fall color, but not every gardener would.
Other shade-loving plants include ferns, bulbs, grasses and even some native plants, including huckleberries and columbine. For those who yearn for summer flowers, look to a few annuals that do well in shade:
fibrous begonias, impatiens, lobelia, nemophila (baby blue eyes) and violas
Gardening under maples or other trees is constrained not only by the shade they provide, but also by the competition of the tree's roots with everything else planted near them. If shrubs are planted at the same time as trees, each has an opportunity to stake a claim on the soil around it and will coexist over time. It's possible, but difficult, to add shrubs, bulbs or grasses after the trees' root systems have expanded into the area where you want to add new plant material. Try small annuals or a few seeds
covered with a thin layer of mulch (keeping it 2 inches away from the tree
trunks), if the surface roots are not too thickly established.
Because of the competition for nutrients and water, trees and shrubs in shade require special attention. I suggest an all-purpose, slow-release, granular fertilizer for trees and shrubs applied in the spring when they leaf out and again in the fall. Azaleas appreciate an additional application of diluted liquid fish emulsion in spring and fall.
Watering a shady garden requires sensitivity to the soil's moisture. Because of shade, the soil may be less dry than in a sunny garden. Temperature and wind are also determinants. Large deciduous trees, such as Japanese maples, are sensitive to drying out, so monitor soil moisture carefully. We use a drip system (for shrubs and trees) and sprayers (for low ground covers), set to go on in summer until the first rains in fall. During the summer months, I check soil moisture by digging a small hole in the soil,
and water only if the soil is dry. Better yet would be a soil probe. Mulch is
critical to protect surface roots from drying out.
One of the main benefits of a shady garden is that, for most of the year, it looks wonderful and requires little care compared with a sunny garden dependent upon perennials, annuals and large flowering shrubs. Pruning is essential, most of which is done in January and February, as is maintaining the right balance of water and fertilizer. Then the garden cheerfully takes care of itself.