Made In The Shade

Hosta happen to tolerate a bit of partial shade.

Modern gardens are shadier now than they ever have been. Ranch houses that were popular through the middle of the last century had those classic big eaves that shaded wide margins close to the homes. Prior to that, tall Victorian houses made big shadows. Modern houses though are even bigger. To make matters worse, lots and garden spaces are smaller and surrounded by ominously tall fences; so there is less space that is not shaded by something sometime during the day.

This is why small trees, sometimes known as ‘micro-trees’, are so popular. They are all that fit into some small gardens without creating too much shade for other plants. Large shrubbery, like some of the larger types of pittosporum, and some of the smaller types of podocarpus, often function quite nicely as small scale trees. Where not too shaded, pineapple guava and New Zealand tea tree are just as effective. They only need to be allowed to develop upper canopies with adequate clearance, while their lower limbs get pruned away, instead of getting pruned to stay down low as shrubbery typically does.

Camellia, hydrangea, aucuba, Japanese aralia, Oregon grape and Heavenly bamboo (Nandina spp.) are appealing shrubby plants for shady locations. Camellias and hydrangeas of course provide impressive blooms during their respective bloom seasons. Camellias also have the advantage of excellently glossy dark green foliage all year;  but hydrangeas are bare and need pruning in winter. Oregon grape and Heavenly bamboo, which are actually related, are more subdued but look more woodsy in bloom, and sometimes provide interesting berries afterward. Aucuba and Japanese aralia do not need showy flowers because their foliage is so bold. Japanese aralia has bigger and bolder leaves, but common types of aucuba are spotted with gold.

Balsam (Impatiens spp.), which is already one of the most popular warm season annuals that is beginning to get phased in as the weather gets warmer, is not quite as colorful in the shade as it is with better exposure, but can be impressive nonetheless. Cyclamen takes shade as well, but will actually be getting phased out through late spring and summer. Cyclamen is actually a perennial that can stay in the garden (if it is not in the way of anything else) to regenerate next autumn. As weather gets warmer in spring, caladiums and coleus can provide remarkably colorful foliage for shady spots through summer and early autumn.

Various types of ferns, although devoid of flower color, provide distinctive and often bold form and foliar texture. Australian tree ferns can actually get quite large and eventually function as small trees. Baby tears is a finely textured perennial ground cover that spreads as far as it has moisture. It can actually get to be invasive.

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Leopard Plant

Leopard plant looks like it would be at home in the garden of Kermit the Frog.

The differences between false ligularia (Farfugium spp.) and real ligularia (Ligularia spp.) are so vague that the the names are commonly interchangeable. Leopard plant happens to be a real Ligularia japonica. The round and very glossy leaves are dark green with random spots of sunny yellow. Mature plants form rather dense foliar mounds about a foot wide and nearly as high. Prominent floral trusses that bloom in late summer or early autumn are a pleasant surprise, even though the small and sometimes feeble daisy flowers are typically only dingy gold, and often have brownish centers. Both ligularia and false ligularia are understory plants that naturally prefer the shelter of larger plants, so they prefer partial shade. They also like relatively rich soil and regular watering, although once established, they can recover efficiently if they happen to briefly get dry enough to wilt.

Western Sword Fern

90911Within its natural range on the West Coast between the southern extremity of Alaska and the southern extremity of California, Western sword fern, Polystichum munitum, is the most common of the native ferns. A few disjunctive wild colonies live as far inland as the Black Hills of South Dakota. Yet, with few exceptions, Western sword fern is difficult to cultivate outside of the natural range.

A fern that is so resilient and undemanding seems like it should be more adaptable. Although foliage is fuller and richer green with regular watering and occasional fertilizing, established plants do not need much at all. They survive in the wild here, with naturally limited rainfall, and just go dormant if they get too dry. Symbiotic soil microbes might be their limiting factor in foreign regions.

The dark evergreen and pinnately compound fronds get about two or three feet long, but can get more than four feet long in damp and partly shady situations. They form thick mounds that mostly obscure lower old fronds that die after their first or second year. Since it is naturally an understory species, Western sword fern prefers somewhat rich soil, partial shade and shelter from dry wind.

Shade Can Be An Asset

90911thumbJust about every home garden has some sort of shade. Even if there are no substantial trees or shrubbery, there are northern walls of homes and garages, and they likely have eaves that extend their shadows a bit farther. Fences to the south create shade to the north. Gardens of modern homes are smaller, and surrounded by higher homes and fences, so are shadier than older gardens.

Those who enjoy gardening tend to enjoy more trees and substantial shrubbery than those who do not enjoy gardening, so generally contend with more shade. It is both and asset and a liability. Cooling shade makes outdoor living spaces more comfortable in the heat of summer, but limits what we can grow. With very few exceptions that are not worth mentioning, all plants need sunlight.

Fortunately, many plants need less than others. Of these, many are understory species, which live in the partial shade of larger plants in their natural environments. Not only do they naturally need less sunlight, many prefer to be in partially shaded or sheltered situation. Their foliage and bloom can be scorched by sunlight if too exposed, especially while the weather is warm, windy or arid.

Plants that prefer partially shaded and sheltered situations are characteristically different from those that prefer more exposure. Their leaves tend to be bigger and darker green to absorb more sunlight. Those that are sensitive to frost may prefer shelter from evergreen shade. To compete for pollinators with bloom above, flowers may be either bigger and more colorful, or more fragrant.

There are, of course, many exceptions. Ferns are probably the most familiar foliar plants for shade, but provide no bloom. Cast iron plant is comparable to fern for providing rich green foliage, but with insignificant bloom. Caladium, coleus and hosta are grown for lush foliage that is strikingly colorful instead of rich green. Hosta contrarily blooms with pastel flowers that are not even fragrant.

Kaffir lily, calla, hydrangea, azalea, rhododendron and impatiens provide more color for partial shade.

Iochroma

90731It is gratifying to see renewed interest in this old fashioned flower. Naturally occurring varieties of some of the nearly three dozen species of Iochroma were popular decades ago. Some might actually be naturally occurring hybrids that have yet to be identified. Many modern cultivars (cultivated varieties) were intentionally bred or hybridized for more compact growth and profuse bloom.

Old fashioned varieties of Iochroma are occasionally seen as large rampant shrubbery or even small trees in old established landscapes. Modern cultivars are more compact and manageable. For the fullest and most vigorous growth in summer, they can be pruned aggressively as winter ends, but should otherwise be pruned only for shape and confinement. They should never be shorn.

If Iochroma resembles angel’s trumpet, it is because they are related. The foliage is very similar, although the leaves are smaller. The narrowly tubular flowers are much smaller and clustered. The hummingbirds who like them so much do not even need to reach their beaks all the way in. Bloom is purple, blue, red, pink or maybe white or yellow. Iochroma happens to do well in partial shade.

Flowering Maple

60622It is impossible to say who the parents were. So many specie were hybridized to develop the many cultivars of flowering maple that the Latin name of the collective group is simply Abutilon X hybridum, which means exactly what it looks like. They are hybrids of various and rarely documented species of Abutilon. The ‘X’ dispels any doubt. ‘Chinese lantern’ is another common name.

Flowers can be yellow, orange, red, pink or pale yellowish white. They look like small hibiscus flowers that do not open all the way, and some only open half way. Many hang vertically. Some hang at about forty-five degrees. Bloom is sporadic all year, and more abundant while weather is warm. The rather sparse evergreen foliage looks somewhat like maple foliage, with variable lobes.

The largest flowering maples do not get much taller than the eaves. Short types stay shorter than two feet. Stems can be awkwardly angular, even if pruned back to promote fluffier growth. Roots can be unstable, necessitating staking or pruning to lighten the load. Flowering maple prefers partial shade, and can tolerate significant shade, but can also do well in full sun if watered regularly.

Rain On The Shade Parade

60622thumbModern urban lifestyles are becoming less conducive to gardening all the time. Bigger and taller homes cast larger shadows over smaller garden spaces. The taller fences between these homes do not help. The densely evergreen trees employed to obscure the views of other larger and taller homes also obscure sunlight. Not much sunlight reaches the ground where shorter plants need it.

While all this is going on, we are supposed to be gardening with more sustainable plants that demand less water. Smaller, shadier and more sheltered gardens should naturally use less water than larger and more exposed gardens need. Yet, the plants that do not mind the shade naturally want more water than plants that want more sunlight. There are not many that are drought tolerant.

Drought tolerant plants are naturally endemic to dry climates. Many are from chaparral regions. Some are from deserts. In such ecosystems where water is too scarce to sustain much foliage, there is not much competition for sunlight. Shade tolerant plants are just the opposite. They are from forested ecosystems with taller and shadier trees. Such ecosystems are sustained by rainfall.

There are quite a few plants that do not mind a bit of shade. Heavenly bamboo, flowering maple, hydrangea, camellia, azalea, rhododendron, holly, daphne and andromeda (Pieris spp.) are some of the more familiar shade tolerant shrubbery; but alas, none are drought tolerant. Nor are the various ferns. Even small shade tolerant trees like dogwood want to be watered regularly.

Most of the plants that tolerate shade but are not too terribly thirsty are groundcover plants or perennials. They are not exactly drought tolerant, but can survive with minimal watering because they do not dry out so much in the shade. Once established in a cool shady environment, plumbago, lily turf, periwinkle Saint John’s wort and coral bells (Heuchera spp.) only need to be watered occasionally through summery weather, although they are thirstier in sunny spots. Both English and Algerian ivy need nothing in the shade.