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.

Polka Dot Plant

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Polka dot plant is mostly pink.

Of all the tender perennials, polka dot plant, Hypoestes phyllostachya, is one of the lesser likely to survive winter outside, even if sheltered from the cold. Yet, it is actually becoming more popular as a warm season folliage plant for pots of small mixed perennials. It is a delightful small houseplant, either alone or as an understory plant to larger houseplants like ficus. As an understory plant, It is easier to work with if grown separately in small pots that can get nestled into moss on top of the soil of the larger plants. If it has a problem, it can easily be replaced or removed.

The foliage typically has so many pink spots that less than half of the foliar surface area is green. Some have white or darker reddish pink spots. The bloom is not as interesting as the foliage, and is not often seen. Roots like rich and evenly moist potting soil. The biggest plants are not much more than a foot high. Most stay less than half as tall. New plants are easy to propagate from cuttings. When things get warmer in spring, plants that have more stems than foliage can be cut back to regenerate.

Barberry

60817It may not look too nasty, but barberry, Berberis thunbergii, is the sort of small hedge that one goes through only once. It does not have big strong branches to hold anyone back. In fact, the limber branches are quite twiggy. The tiny spines are not impressive either, and might go unnoticed by cursory observation. Yet, they are sharp enough and plentiful enough to make quite an impression!

Because it is so unpleasant to prune, barberry should probably be planted where it has room to grow as big as it wants to without bothering anyone. If it is too close to walkways, it will either offend whomever bumps into it, or whomever needs to prune it to keep it out of the way. Mature plants will unfortunately need to be pruned eventually, so that old deteriorating stems can be groomed out.

The most popular cultivars of barberry have dark reddish or purplish foliage. A few are variegated with white; and a few have golden foliage. Green barberries are now uncommon. The tiny leaves turn bright orange in autumn before winter defoliation. Densely dwarf cultivars may not get much taller than two feet. Taller cultivars might get taller than six feet. Some barberries are very vertical.

Colorful Foliage Fades Through Summer

P90713Autumn foliar color is not the concern yet. It develops later as deciduous plants defoliate for winter. Purplish, reddish, yellowish, bluish or gray foliar color that can be seen now is provided by plants that are colorful while actively growing. Almost all of this sort of foliage is most colorful when it is young and fresh, early in spring. Then, through summer, some of the best foliar color fades.

This process is perfectly natural. It does not imply that anything was done improperly, or that plants were not given what they need. In fact, most plants with colorful foliage would rather be green. They are mutants that were reproduced specifically for their distinctive color. Some try to revert back to green by producing greener shoots that grow faster because they have more chlorophyll.

Photinia is an odd one. By now, The rich green foliage shows no clue that it was rich reddish bronze when it developed early in spring. The foliage did not really fade. It merely matured. Then there are the newer cultivars of purple leaf plum, which maintain their color from spring to autumn. It is amazing that such darkly colored foliage that seems be devoid of chlorophyll can photosynthesise!

Some plants maintain their color better than others. Gray or bluish foliage is always gray or bluish; but admittedly, blue spruce and blue junipers are not quite as striking now as they were earlier. If red fountain grass and bronze aonium fade, it will be too slight to notice. Stems of bronze, gold or striped cannas that fade after bloom get pruned out in favor of more colorful unbloomed stems.

‘Forest Pansy’ redbud, ‘Summer Chocolate’ silk tree and ‘Sunburst’ honeylocust are notorious for fading. By now, the formerly richly bronzed redbud and silk tree merely seem to be stained with coffee. Golden honeylocust might have been bright yellow in spring, but now just looks sickly. Gold tipped and silver tipped deodar cedars can likewise be a bit pale. Bronze elderberries hold color well, but golden elderberry might now be chartreuse.P90713+

Silver

P90713KThese are two pictures that did not make the grade for my ‘Six on Saturday‘ post this morning. That post featured bronze and gold foliage. Actually, of the six, only two were bronze, and only one was truly gold. One that I passed off as bronze was more purplish. Two that I thought were gold were just variegated with yellowish green and white.

I am none too keen on bronze or gold foliage anyway. The only exception that I can think of is the old fashioned bronzed ‘Schwedleri’ Norway maple. It was planted as a street trees on a few streets in the Santa Clara Valley in the 1950s.

Bronzed cultivars are less vigorous than their greener counterpart.

Gold cultivars are even less vigorous, and susceptible to scorch.

The best quality about bronze and gold is that they make silver look so good.

Olympic medal designations really should be reconsidered.

I only featured bronze and gold foliage earlier because I liked the contrasts between two different cultivars of each of the three species that were featured. Ironically, none of the three pairs compared bronze to gold directly. One compared purple to gold. The other two compared bronze to variegation that was barely yellow. Oh well.

There are neither bronze nor gold cultivars to compare to the silver foliage of the two species shown here.

I do not know what species of agave this is. There are not many distinguishable features visible in the picture above. The color and texture of the foliar surface might be identifiable to an expert. The little snail does not seem to be at all concerned.

The Eucalyptus cinerea in the picture below was pruned aggressively last autumn, both to contain the disfigured canopy, and also to stimulate more vigorous new juvenile growth. It is now strikingly silver.P90713K+

Six on Saturday: No Silver

 

We have bronze, and we have gold, but we have no silver, at least not in these six pictures. I suppose I could have posted a picture of Eucalyptus cinerea or Echeveria glauca. I thought it would be more interesting to contrast two different cultivars of each of these three species. Only two are truly bronze. Only one is truly gold. They contrast nicely anyway.

1. Bronze smoke tree – Cotinus goggygria – Modern cultivars with richer color like this are now considered to be ‘purple’. When I studied it in the 1980s, the old fashioned bronze cultivars were still available.P90713

2. Gold smoke tree – These might not have been available back in the 1980s. I do not remember every seeing one. I am not often impressed with their vigor; but I have seen them doing quite well in some situations.P90713+

3. Bronze canna – Canna spp. – I believe this is the cultivar ‘Wyoming’, with bronze foliage and rich orange bloom. The bronze color does not show up well here. Other cultivars are much darker purplish bronze.P90713++

4. Gold canna – Just as the bronze cannna is more bronze than it looks here, this one is more golden, particularly when the foliage is new. Obviously, it is variegated as well. The foliage is as interesting as the bloom.P90713+++

5. Bronze New Zealand flax – Phormium tenax – It might be known by a cultivar name rather than the species name of ‘tenax‘ followed by a cultivar name. Weird modern hybridization complicates nomenclature.P90713++++

6. Gold New Zealand flax – I really though that this one was ‘Yellow Wave’, but it does not look like that here. The variegation is more white than yellow. Could this variegation instead be classified as silvery?P90713+++++

This is the link for Six on Saturday, for anyone else who would like to participate:

https://thepropagatorblog.wordpress.com/2017/09/18/six-on-saturday-a-participant-guide/