Coral Bells

Most coral bells are grown for their colorful foliage.

From Santa Barbara to Vancouver, and also in central Idaho, the humble native coral bells, Heuchera micrantha, is not much to look at, with compact rosettes of relatively small and bronzy rounded leaves with weird tomentum (hairs). In spring and early summer, and sometimes again in autumn, sparse trusses of minute brick red flowers hover about a foot above on wiry and slightly fuzzy stems. Old plants that get bare in the middle can be divided into several small plants in spring or autumn.

Modern cultivars are considerably more interesting, with more substantial foliage in various shades of green, gold, tan, brown, bronze and purplish bronze. The larger and variably lobed leaves can be two inches wide or slightly wider. The flowers stand as much as two feet high, but lack color. Most are pale greenish white. ‘Palace Purple’ has deep bronze or almost purplish foliage. ‘Ruffles’ has deeply lobed and ruffled green leaves. Unlike undemanding wild plants that can grow in cracks in exposed stone, modern cultivars like rich soil. Harsh exposure can scorch foliage, so a bit of partial shade is preferred.

Many coral bells have delightful bloom as an added bonus to their foliage.

Coleus

Coleus works both inside and out.

Without bloom, the richly vibrant foliar colors of coleus, Coleus scutellarioides, rival floral color of other warm season annuals. Striking foliar patterns are as exquisite as any floral display. Growth is efficient through the warmth of spring. Foliage might last until autumn. Late in its season, spikes of tiny blue flowers can be trimmed off to promote more foliage. 

With bright ambient sunlight, coleus is more perennial as a houseplant. However, it may get persistent with pesky bloom as it matures. Some who grow it prefer to let bloom, and then prune it back afterward. Recovery from such pruning can be slow. Vegetative stems, without bloom, root easily as cuttings even in water. New cuttings can replace old plants. 

Coleus foliage is intricately variegated with countless combinations of green, chartreuse, yellow, orange, red, burgundy, pink, white and brown. Variegation can be symmetrical or random. Leaf margins may be deeply lobed or just serrate. Modern cultivars might be no better than old fashioned sorts. Mature plants can get as tall and broad as about two feet. Some stay lower.

Variegation And Other Foliar Color

Bright white variegation brightens shady spots.

Foliar color is not limited to autumn. Some deciduous plants display colorful foliage from spring to autumn. Then, some of these change color for autumn. Some evergreen plants display colorful foliage through the year. Variegation of foliage can be more colorful than associated bloom. So can unvariegated bronze, purple, red, yellow, blue or gray foliage.

All sorts of plants exhibit variegation or other variations of color of their foliage. They can be annuals, perennials, shrubs, vines, trees, or houseplants. Although many are popular primarily because of their foliage, some provide appealing bloom as well. Blue and gray foliage is a natural advantage in harsh climates. Other colors are selections of mutations. 

Because variegation deprives portions of foliar surface area of the chlorophyll needed to perform photosynthesis, it inhibits growth. This can be an advantage for plants that grow too vigorously otherwise. However, many variegated plants occasionally develop growth that is not variegated. If not removed, it can overwhelm and displace desired variegation. 

New Zealand flax, dracaena palm (Cordyline australis), gold dust plant, euonymus, coral bells and hosta are some of the many plants that are more familiar with colored foliage or variegation than without. If simple unvariegated coleus, croton or caladium are available, they must be notably rare. Blue spruce is always blue. Purple leaf plum is always purple. 

Although both gold and gray junipers are popular, the most common are green. Bronzed and variegated cannas are likewise not quite as popular as those with simple lush green foliage. Pittosporum tobira is so much more vigorous without variegation than with it, that the two distinct types of this same species perform different functions within landscapes.

Golden honeylocust supposedly produces lighter shade than darker green honeylocust. ‘Ruby Lace’, a bronze cultivar of honeylocust, supposedly produces faintly darker shade. Some golden or variegated foliage is more susceptible to scorch; although sun exposure enhances foliar color and variegation. Fresh new spring growth gets the best foliar color, but is likely to fade through summer.

Smoke Tree

Smoke tree has striking foliage too.

Wispy billows of pinkish or tan blooms through June and July are what the smoke tree, Cotinus coggygria, is named for. It probably should have gotten more recognition for brilliant foliar color in autumn. It reliably turns bright yellow and orange, and if the weather is right, it can turn rich red and even purplish. Until then, the popular modern varieties have either dark purplish or light yellowish foliage. Some of the older plants have slightly bluish green foliage. The nearly circular leaves are about two or three inches long. Yellowish varieties tend to be shortest. Those with purplish or bronze foliage get larger. Old fashioned green plants are the largest, and can get twelve feet tall and broad. Smoke tree can be large shrubbery, or pruned up as small trees. Aggressive pruning in winter promotes better foliar color through spring and summer, but inhibits smoky bloom. Slightly distressed plants have better color in autumn. Plants that are watered too much are likely to succumb to disease within only a few years.

Foliage Can Provide Color Too

There is considerable variety in variegation.

Flowers get all the credit for color. They certainly are the most colorful features in the garden, as well as the most fragrant. However, foliage can do so much more than simply provide green. It can be hued with yellow, red, blue, purple, bronze, gray, or variegated with white or yellow. Plants with colorful foliage can range in size and function from small annuals and perennials to shrubbery, vines and even trees.

Hydrangea, hosta, ivy, English holly and various pittosporum are some of the more popular plants for white variegation, and are often variegated with yellow. Euonymus can conversely be variegated with white, but is usually variegated with yellow. New Zealand flax can be variegated with pink, bronze, brown or gold. Box elder is a good sized deciduous tree that can be variegated with white, or alternatively frosted uniformly with gold as new foliage emerges in spring. There is even a variety that has slightly purplish or smoky colored new foliage.

Silver mountain gum, silver Mediterranean fan palm, lamb’s ears, artemesia and the various dusty millers have remarkably silvery foliage. Silver mountain gum can grow into a mid-sized tree with a stout trunk. Lamb’s ears is a low perennial. Olive trees, some junipers and the various lavenders have gray foliage. Colorado blue spruce and some agaves have striking blue color.

Various purple leaf plums and Japanese maples are famous for their purplish foliage. Smoke tree and some beech have even darker purplish foliage. Some New Zealand flax and cannas can be just as purple or comparably bronze.

Actually, New Zealand flax and cannas, as well as junipers known for blue or gray foliage, can alternatively be bright yellow. Golden arborvitae, golden honeylocust and golden Monterey cypress really stand out nicely against darker green.

Colorful foliage tends to be most colorful as it develops freshly in spring, and tends to fade somewhat through summer. Gold junipers can actually fade to basic green by autumn. Shade inhibits most types of coloration, but can show off variegation better. There really is so much variety with colorful foliage that it is impossible to generalize.

Coral Bells

Coral bells can bloom again in autumn. (This is not my picture.)

From Santa Barbara to Vancouver, and also in central Idaho, the humble native coral bells, Heuchera micrantha, is not much to look at, with compact rosettes of relatively small and bronzy rounded leaves with weird tomentum (hairs). In spring and early summer, and sometimes again in autumn, sparse trusses of minute brick red flowers hover about a foot above on wiry and slightly fuzzy stems. Old plants that get bare in the middle can be divided into several small plants in spring or autumn.

Modern cultivars are considerably more interesting, with more substantial foliage in various shades of green, gold, tan, brown, bronze and purplish bronze. The larger and variably lobed leaves can be two inches wide or slightly wider. The flowers stand as much as two feet high, but lack color. Most are pale greenish white. ‘Palace Purple’ has deep bronze or almost purplish foliage. ‘Ruffles’ has deeply lobed and ruffled green leaves. Unlike undemanding wild plants that can grow in cracks in exposed stone, modern cultivars like rich soil. Harsh exposure can scorch foliage, so a bit of partial shade is preferred.

Most coral bells are grown more for their colorful and low foliage than for their bloom. (Both pictures here were obtained online. I can not find my pictures.)

Smokebush

00624Cliche is barely avoidable regarding smokebush, Cotinus coggygria. It provides rich foliar color from spring until autumn, with uniquely billowy bloom through summer. Then, it provides exquisite fall color until winter. Then, it provides sculptural form of bare stems until spring. Smokebush ‘has it all’. . . almost. All the spectacle distracts from a lack of floral fragrance. Will anyone ever notice?

Foliage is rich purplish bronze, bright greenish yellow or olive green through spring and summer. Formerly common old fashioned cultivars with olive green foliage are now rare. Nowadays, most are rich purplish bronze. Fall color is fiery yellow, orange and red. The round leaves are about one to three inches long. Purplish to pale pinkish plumes of smoke-like bloom are a striking contrast.

The largest of smokebush grow at a moderate rate to more than fifteen feet high and wide. Most cultivars are more compact. They get wobbly in the ground if they grow too vigorously. Aggressive pruning during winter improves stability and enhances foliar color for the next season. However, minimal pruning of stable plants promotes bloom. Smoke tree wants full sun, but is not demanding.

Bronze Is The New Green

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Color like this needs no bloom.

Bronze foliage will never actually replace green foliage. Even if there were enough variety of plants with bronze foliage to do so, too much bronze would look dreary. Bronze is just another option for foliar color in landscapes with significant vegetation. It is distinct from simpler green, and contrasts nicely with gold, blue, gray and variegated foliage. Some bronze foliage is variegated too.

There is all sorts of bronze foliage. Some is brownish bronze. Some is reddish. The most popular bronze foliage is rather purplish. It can be evergreen or deciduous. Annuals, perennials, shrubs, vines, trees and houseplants can provide bronze foliage. Most plants that provide bronze foliage are variants of plants that also provide bloom or fruit. Some are common. Others are rather rare.

Bronze foliage is not an advantage to plants that produce it. The most efficient foliage is green. Gray or bluish foliage has the advantage of reflecting some of the harsh sunlight that could scald it in severe climates. Otherwise, foliage that is a color other than green reflects more of the useful sunlight than it should. Incidentally, dark foliage also absorbs more of the sunlight that can scald it.

This is why many bronze plants are noticeably less vigorous than their greener counterparts. Although it would not be an advantage in the wild, diminished vigor makes some bronze plants more adaptable to compact home gardens. For example, the brownish bronze ‘Summer Chocolate’ silk tree will not get half as high and wide as the common silk tree. It can fit nicely into a cozy atrium.

Cultivars of purple leaf plum, Japanese maple and Eastern redbud are more familiar complaisant bronze trees. ‘Ruby Lace’ honeylocust is still quite rare. Bronze shrubbery includes smokebush, Chinese fringe flower, elderberry, barberry and ninebark. New Zealand flax, canna, houseleek, ajuga, mondo grass and coral bells are popular bronze perennials. Cordyline is a larger perennial.

Bronze foliage adds a bit more color than typical green foliage. In the right situations, it is appealing bold.

Mediterranean Spurge

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Peculiar bloom tops handsomely colorful foliage.

Seed for this species is all or nothing. The straight species of Mediterranean spurge, Euphorbia characias, seeds abundantly. It can actually be a bit too prolific. However, fancier and extensively bred cultivars either produce no viable seed, or produce only a few seed that are not true to type. Such seed grows into plants that resemble their ancestral species more than their direct parents.

Foliage of common Mediterranean spurge is slightly grayish green. Cultivars exhibit more distinctly grayish, bluish, yellowish or variegated foliage. Appealingly weird and generally greenish floral trusses bloom on top of upwardly arching stems about now. Mature plants are less than four feet tall and broad, with neatly rounded form. They slowly lean toward sunlight as they grow and bloom.

After old stems get cut to the ground in autumn, new stems develop through winter, to repeat the process. Established plants are surprisingly resilient to harsh exposure, warmth, wind and lapses of irrigation. They just dislike shade and constant dampness. However, even the healthiest live for only five to eight years. Those that toss seed can provide their own replacements before they go.

Black Mondo Grass

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The foliage really is this dark.

The deeply colored foliage of black mondo grass, Ophiopogon planiscapus ‘Nigrescens’, is about as convincingly ‘black’ as foliage can get. It is darker than bronze New Zealand flax, purple leaf plum or bronze coral bells. Only purple beech or chocolate coleus are comparable. The foliage is dark enough to contrast very well against lightly colored planters or gray concrete, so works well in urns or mixed perennials, and bordering walkways. If it gets enough sunlight, black mondo grass makes a nice small scale ground cover under Japanese maples.

Mature plants stand only about half a foot tall, and spread slowly. The happiest plants can get nearly twice as tall. The softly cascading leaves are only about a quarter inch wide. Small spikes of tiny pink flowers that sometimes bloom in summer would contrast nicely against the dark foliage, but are rarely seen above the foliage. Black mondo grass prefers rather rich soil and somewhat regular watering. However, as they disperse roots, older plants do not seem to mind too much if they briefly get a bit dry.