Color Is Lacking This Autumn

41029thumbSweetgum, flowering pear and Chinese pistache are the most reliable trees for flashy autumn foliar color, especially in such mild climates. They may not seem like it this year though. After a late start, only sweetgum is coloring well. Flowering pear trees that are beginning to show color farther inland seem to lack their typical bright yellow and orange, and are showing more dark rusty red.

Like so many flowers that bloom in spring, foliar color in autumn is as variable as the weather. Temperature and humidity can either inhibit or enhance color. It is impossible to say what caused the disappointing color so far, or if foliage that colors later will be just as bland. A sudden chill could change things for Chinese pistache that are still behind schedule.

Maidenhair tree (gingko) is the best for bright yellow, but lacks any other color. Fruitless mulberry, tulip tree and various poplars can be nearly as bright yellow in a good season, and may still color well. Of the various willows, only a few color well, and they tend to be more sensitive to weather. Early rain can rot their leaves before they get much color at all.

Although elms are not known for coloring, some of the modern varieties turn remarkably bright orange. However, the few oaks that color well in colder climates turn only dingy brown locally. The few North American maples that can provide color do not hold their colored foliage very long. All sorts of trees have all sorts of personalities.

Eastern redbud, smoke tree and crape myrtle are shrubs or small trees that color as well as larger trees in autumn. Crape myrtle can be as bright yellow, orange and red as sweetgum. Some Japanese maples color better than others, and some can be quite impressive, but only if their foliage does not get roasted by warm and arid weather through summer.

Where it can be accommodated, Boston ivy is an aggressively clinging vine that provides all the remarkably colorful foliage on freeway sound-walls. It is out on the freeways for a reason though. It can ruin any other surface that it clings to.

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Dyckia

91023It is easy to mistake various cultivars of Dyckia for diminutive relatives of Agave or Yucca. They form stout rosettes of rigid leaves with wickedly sharp terminal spines. Their comparably nasty but incurved marginal teeth resemble those of most species of Agave, but are generally more abundant. Surprisingly though, Dyckia are instead related to bromeliads. They just happen to be xeric.

Dyckia do not bloom much, but when they do, the tall and arching floral stalks really are more typical of bromeliads. As they bloom late in spring or in summer, the many small individual flowers on each stalk are collectively colorful enough to be delightfully popular with hummingbirds, butterflies and bees. Bloom is most commonly rich reddish orange, but some cultivars bloom red or yellow.

No one seems to mind that Dyckia does not often bloom. The foliage is remarkably striking alone. Many cultivars form dense mounding colonies of pups that, although unpleasant to handle, can be divided for propagation. A few toothless cultivars, armed only with terminal spines, are easier to handle. Individual rosettes can be as tall and broad as a foot. Dyckia do not need much water.

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+

Foliar Color Long Before Autumn

51104The best and brightest color in the garden is obviously still provided by flowers. Autumn color can be spectacular, but only amongst relatively few deciduous trees, shrubs and vines that turn color reliably in mild climates, and only if the weather is conducive to coloration. The next best option for color beyond green is the sort of colored foliage that does not wait for autumn to materialize.

Foliage can be shaded with varying degrees of yellow, red, pink, purple, bronze, grayish blue or gray, or variegated with white, yellow or silvery gray. Plants that display such colorful foliage can be as small as flowering annuals, or as substantial as shade trees. Many are deciduous plants that also turn color in autumn. Most of the best are actually evergreen, so hold their color through winter.

Color tends to be richest as new foliage emerges in spring, and fades more or less through summer. Gold junipers only start out gold, but then fade to green within only a few months. The purplish foliage of ‘Forest Pansy’ redbud fades to coffee stained green. Yet, bronze New Zealand flax is always bronze. Dusty miller is always gray. Some plants are more reliably colorful than others are.

Exposure is important too. Most blue or gray foliage, whether juniper, agave, spruce, eucalyptus, olive or silver Mediterranean fan palm foliage, will be significantly greener if shaded. However, white variegation of English holly, hydrangea, ivy, hosta and pittosporum have better contrast if partly shaded. Colorful Japanese maples color better with good exposure, but roast if too exposed.

Many plants with colorful foliage are notorious for developing greener mutant growth known as ‘sports’. Because sports have more chlorophyll, they grow more vigorously than more colorful growth does, and can overwhelm and replace the more desirable colorful foliage if not pruned out. Many types of white or yellow variegated euonymus, as well as the more intricately variegated New Zealand flax, can revert to monochromatic green within only a few years.

Premature Color

P80819Halloween is my all time least favorite of the fake holidays. I will not elaborate on this now, but will say that the appearance of Halloween decorations as soon as the Fourth of July decorations were outdated on the fifth makes me dislike Halloween even more. Halloween is an autumn pseudoholiday. It is not meant for summer!
Autumn foliar color, or fall color, is known as such because it happens in ‘fall’ . . . or autumn. It is not meant for summer any more than Halloween is.
This little Japanese maple did not get the memo. Perhaps it thought that no one would notice if it got an early start. It was a nice bronze in spring and the early part of summer, and somehow managed to maintain good color without roasting when the mild weather so suddenly became more seasonably warm a while back, but is now turning this nice pinkish red as if it is done for the year. This picture is slightly more than week old, so this little tree has been slowing down for a while already.
I can not complain. I am actually impressed that this tree did not get roasted when the weather changed earlier. Japanese maples are susceptible to scorch in our arid climate, and the ‘lace leaf’ cultivars are the most sensitive. More resilient foliage, including English laurel cherry, got roasted.
What will this Japanese maple look like in autumn? I can not predict. It would be nice if it held the premature color through autumn and defoliated on schedule in winter. It might defoliate as prematurely as it colored, leaving it bare part way through autumn. The bark could scald if too exposed while the sun is still high and warm. The weather will determine what happens next.

Mirror Plant

70510As the old fashioned larger mirror plant, Coprosma repens, fell out of favor through the 1990s, several more colorful varieties of a more compact species of mirror plant, Coprosma X kirkii, became popular. (The ‘X’ in the name indicates that it is actually a hybrid of two specie.) Without getting much more than two feet deep, it spreads out laterally like dense evergreen groundcover.

The color is not from bloom, but from the very glossy foliage. It can be variegated with white, gold, red, pink or bronze, or completely brownish bronze. Some varieties stay very shallow. Others can be shorn into low hedges like Japanese boxwood, only shorter. Although mirror plant does not mind partial shade, foliar density and color is best with full sun exposure and occasional watering.

Most modern varieties are known by their cultivar names, without their specie names. For example, Coprosma ‘Tequila Sunrise’ lacks the species name of ‘X kirkii‘. Such omissions might be the result of confusing hybridization with Coprosma repens, for rounder leaves. In other words, some cultivars may be of ‘questionable parentage’. Some are just dwarf cultivars of coprosma repens.

Foliage Shows Its True Colors

70510thumbFlowers were originally colorful only to attract pollinators. Breeding has improved the color and quality of many garden varieties of flowers, to make them more appealing to the people who grow them. Some have been bred so extensively that they are sterile, which defeats the original function of flowers. Now their function is merely to look good in the garden. Improvements are relative.

Foliage is green because it is photosynthetic. Chlorophyll, which is necessary for photosynthesis, happens to be green. Yellow, red, blue, purple, bronze, gray and variegated foliage might not be as efficient at photosynthesis as green foliage, but can be appealing in home gardens. Many plants with colored foliage are inferior to their greener counterparts, but are somehow more popular.

Gray and blue foliage absorbs less sunlight, which can be an advantage in harsh environments. Blue hesper palm and the various blue agaves are from arid deserts. Colorado blue spruce is from high elevations of the Rocky Mountains. Arizona cypress, silver mountain gum, artemesia, lambs’ ears, lavenders, dusty millers and blue junipers all provide distinctively gray or blue foliage.

Golden arborvitaes and junipers can be strikingly gold as new foliage develops in spring, even if the color does not last long. Most plants with gold foliage fade to yellowish green through summer. Golden honeylocusts do not fade as much, so are still mostly yellow by the time they defoliate in winter. Purplish or reddish foliage of purple leaf plum and red Japanese maple holds color better.

Euonymous, English holly, osmanthus, silverberry, hosta and various pittosporums can be variegated with white or yellow. Ivy, and hydrangea can be variegated with white. New Zealand flax and mirror plant can be variegated with gold or bronze, . . . or red or pink. Any unvariegated mutant growth (known as ‘sports’) that appears on variegated plants should be pruned away. Because it has more chlorophyl, it grows more vigorously, so can overwhelm and replace the more desirable variegated foliage.70510thumb+

Ecclesiastes 3: 1

P80207There is a time for everything, and a season for every activity under the Heavens:

Verses 2 through 8 continue to list a few examples of more specific activities that happen at specific times. If there were more examples, autumn foliar color would probably be cited as well. After all, autumn foliar color happens in . . . well, . . . autumn.

Perhaps it was omitted for brevity. Of course, there is the possibility that it was omitted to avoid confusion. If it had been cited, it might have been described simply as ‘foliar color’ rather than ‘autumn foliar color’. Some foliage colors earlier if distressed. Some foliage does not color until frosted. Some might even delay color until it is in the process of getting replaced by new foliage. Then there are the many sorts of evergreen foliage that do not color at all, or at least in a manner that is visible or notable from outside. Shedding browned or blackened dead foliage, particularly that which is obscured by new foliage, does not count.

This English ivy foliage is the sort that should not color at all. Old leaves should whither and deteriorate once obscured by new foliage. Perhaps the vine is concentrating resources elsewhere while abandoning this section. Perhaps the entire vine is deteriorating. From this picture, it is impossible to determine why this colorful foliage is exposed.

Perhaps this is the time to just appreciate nice autumn foliar color wherever and whenever we get it, even if it is on English ivy in winter. As the flowering cherries try to convince us that it is spring, that would be just fine too. This can be the time for autumn, spring, and maybe even winter if it ever arrives, all at the same time.

Leaves Leave

P80104+I do not know where they went. There are plenty that are not worth getting pictures of, but the pretty and colorful ones that I wanted to show off in the ‘Six on Saturday’ post are gone. I suppose that they are still out there. They just are not as pretty and colorful as they were earlier.

Pistache leaves deteriorate quickly. They were very colorful while still in the trees, but were not much to look at by the time they were on the ground.

Ginkgo colored well too, but after I got that one picture of the single leaf, I could find no others. The tree that sent that leaf is not in the neighborhood. ( https://tonytomeo.wordpress.com/?s=birthday )

I suppose that I could have gotten a good picture of a colorful sweetgum leaf. I just did not bother with them. Nor did I bother with flowering pear.

California sycamore does not color very well. It was a bit more colorful this year than it typically is, with a bit more orange in the hazy brownish tan, but still nothing too flashy. The leaves are not very pretty anyway. They are sort of big and flabby . . . and awkwardly asymmetrical. I mean, every leaf seems to be disfigured. They are not neat and distinguished like maple leaves are. I took this picture of a deteriorating leaf of a California sycamore because it was more interesting than colorful. There is barely any gold or orange left in it. Gray blotches left from anthracnose or powdery mildew certainly do not add much to the color. This leaf is unusually big because it came from a vigorous watersprout.

The heart shaped cottonwood leaf is still somewhat gold, with gray around the edges. Cottonwoods actually color nicely in other climates. Local trees defoliated faster than the foliage could turn yellow. They really did not like the late weather this year.P80104++