Slow Color

P91110Autumn is not much to brag about here. It supposedly got just cool enough at night for the minimal requirement of frost, at 32 degrees, but no one noticed. It has been getting to the low 80s during the day. There has been no rain yet, and none is in the forecast. As bland as such weather seems, it is not at all out of the ordinary. Autumn often arrives later than it does elsewhere.

Consequently, autumn foliar color is not much to brag about either. There are only a few trees that reliably develop good color, such as sweetgum, pistache, flowering pear, crape myrtle and maidenhair tree (ginkgo). As reliable as it is, maidenhair tree provides only bright yellow, without the oranges and reds that the others exhibit. None are exhibiting significant color just yet.

There are several other trees that have potential to develop good color, but are not as reliable about doing so. Birch can get almost as brilliant yellow as maidenhair tree does, but does not do it every year. Red oak may turn brilliant orange with a bit of brownish red mixed in, but only every few years or so. On rare occasion, even London plane (sycamore) shows off burnt orange.

Every species has a distinct personality. They each respond differently to different variables. Weather conditions that stimulate good color among flowering cherries may not stimulate good color for bigleaf maples. Dogwoods that colored so well at about the same time last year as the tulip trees, are already nearly bare after minimal color, while the tulip trees are mostly green.

Every few years, if mildly but suddenly chilled, these cottonwood develop a brighter yellow, with less blotching. With slower and drier chill this year, they are deteriorating and falling without much yellow at all.P91110+

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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.

Snowball Bush

90424Long before hydrangea blooms with its distinctively round floral trusses of abundant small flowers, the snowball bush, Viburunum opulus ‘Roseum’, shares its own unique version of similar bloom. Although the cultivar name suggests that the bloom would be pink or red, it is exclusively white. Hydrangea will bloom later, mostly in pink or red, with some in blue or lavender, and a few in white.

The snowball blooms of snowball bush are about thee inches wide, so are smaller than those of hydrangea, and do not last quite as long. They bloom early in spring, without subsequent bloom. The two or three inch long deciduous leaves might turn surprisingly vivid orange and red before defoliating in autumn. Mature specimens easily get taller than ten feet, and might reach fifteen feet.

Snowball bush eventually develops a relaxed and unrefined style that fits nicely into woodsy landscapes. Autumn foliar color is better with full sun exposure, but a bit of partial shades promotes a slightly more open branch structure that displays the spring bloom better. Pruning should be done after bloom. Snowball bush prefers somewhat regular watering and rich soil, but is not too finicky.

Rhus diversiloba / Toxicodendron diversilobum

P81209This would be a good topic for one of my rants on Wednesday, except that it is too silly for that.

Many years ago, before I started writing my gardening column for our local newspapers, my colleague Brent and I used to exchange funny newspaper gardening articles. Some were obviously not written for local climates. Some were just very inaccurate. Back then, it was done by mail, so the articles were added to anything that we happened to be sending to each other at the time. If I sent him some seeds, I would add an article or a few from the San Jose Mercury News. If he sent my cuttings, he would add an article or a few from the Los Angeles Times. They eventually became the inspiration for my gardening column, when Brent and others told me that rather than making fun of the inaccuracies of the articles, I should provide accurate articles.

One of the silliest that Brent sent to me was an otherwise well written article about star jasmine. Most of the information about it was accurate, until it got to describing the colors of the exclusively white bloom. The article explained that star jasmine bloomed in vivid shades or blue, purple, red, orange and yellow; just about every color except for white!

Well, I topped that with an article about protecting Japanese maples from theft, which sounded crazy even before reading the article. There were three recommendations. The first was to surround the subject Japanese maple with razor wire. Ah, the ambiance! The second recommendation was to dig a hole about as big as a trash can and fill it with concrete with a curved piece of rebar to make an enclosed loop on top, and then chain the subject Japanese maple to it. How about we just do without a Japanese maple in the front yard in a neighborhood where we expect it to get stolen. The third recommendation was to plant poison oak around the subject Japanese maple. Yes, good old fashioned poison oak, Rhus diversiloba, which is also known by the more descriptive Latin name of Toxicodendron diversilobum, and commonly available at . . . . some nursery . . . . somewhere. . . . You know, one of those . . . . garden centers . . . . or something.

Silly? Yes! What is sillier is that poison oak really IS available from certain nurseries that sell native specie! What is even SILLIER than that incredible degree of SILLINESS is that one of the so-called landscape companies that I worked for in about 2006 actually procured some for habitat restoration outside of, but adjacent to a newly landscaped area on the banks of where the Guadalupe River flows through San Jose. Poison oak and other native vegetation needed to be eradicated for the installation of the new poison oak and associated irrigation system, because nothing is more natural than supplemental irrigation! Then, the ‘gardeners’ had to conduct regularly scheduled weed abatement so that poison oak growing from seed tossed by the pre-existing poison oak did not grow up and compete with the new poison oak in the new ‘natural’ ‘landscape’. We certainly would not want poison oak taking over the poison oak.

Okay, this is not Wednesday, so I will finish this rant.

Poison oak happens to provide some of the best orange and red autumn foliar color in our region where almost all of such color is simple yellow. Where it is out of the way and not bothering anyone, it is sometimes left to climb high into trees, where it colors almost as well as flowering pear. Yes, it is pretty, but I will not be planting any of it.P81209+

Six on Saturday: Too Much Autumn Color III – Cherries, Berries, Plums, Apples, . . . & Ginkgo

 

Autumn foliar color, fall color, autumn leaves or whatever you know it as; there was too much of it to fit into just six pictures. That is why I submitted two ‘Six on Saturday’ posts last week, and why this one is number ‘III’, and why there will be a number ‘IV’ right afterward. Only one reader expressed concern that submitting two posts to ‘Six on Saturday’ on the same Saturday is a violation of the rules, but I got the impression that even he did not mind. These pictures, as well as the next six, were actually taken more than a week ago, which might violate another rule. If you are seeing them now, I have not yet been prosecuted, and compelled to delete them. Much of the foliage was knocked to the ground by rain since the pictures were taken. The apple tree #4 was pruned back severely, and is now completely defoliate. The title ‘Cherries, Berries, Plums, Apples, . . . & Ginkgo’ implies that all but one are fruit trees; but they aren’t. Well, you can see what I mean.

1. Yoshino flowering cherry, which I know as ‘Akebono’, just might be the most traditional of the Japanese flowering cherries in America. It is the classic cherry blossom tree around Washington D. C.. As flashy as the bloom is, it is sterile; so the trees are fruitless. You can not see it, but the home in the background is of classic Early American architecture. It is a family home, so is too big for my taste. It would otherwise be my favorite home in the neighborhood.P8215

2. Kwanzan flowering cherry is the second most popular flowering cherry in our region. The big pink double flowers are a bit too garish for my taste, but they really are flashy! Like the Yoshino cherry, the Kwanzan cherry is fruitless.P8215+

3. American plum is not native here, but naturalized. It was and probably still is a common understock for quite a few of the stone fruits. It often grows from the roots of a stone fruit tree that got cut down to the ground. It makes small tart plums that are not much bigger than fat cherries, but not many of us use them for anything. Garden varieties of plum and cherry are naturally more desirable. I Intend to use American plum for jam, but I always get out to pick them after they have fallen to the ground and gone bad. You may have noticed that the first three subjects are of the same genus, Prunus.P8215++

4. Apple happens to do very well in our region. The old apple trees on the farm are remnants of an old orchard. Others in the neighborhood are from old farms. This one is on the edge of a sidewalk where it was not likely planted intentionally. It likely grew from a seed from a discarded apple core. It does happen to make apples, but they are no good. I just cut this tree back severely. If the apples are still no good next year, the tree might get cut down.P8215+++

5. Ginkgo is an ornamental tree here. Because those of us who do not want the fruit find the stinky aroma and mess to be objectionable, garden varieties are all male, and therefore fruitless. However, in some cultures, ginkgo is grown both for fruit, and for the nuts within the fruit. There are a few female trees in older neighborhoods here. They were grown from seed before all male garden varieties were developed. Back then, there was no way to determine the gender of a ginkgo tree until it started to develop fruit . . . or hopefully didn’t.P8215++++

6. Barberry is strictly ornamental. I have never actually seen a bar’berry’ fruit. This particular unknown cultivar happens to be bronzed, with very dark foliage that turns bright yellow and orange for autumn. It is very thorny!P8215+++++

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/

Crape Myrtle Finale

P81201KIt is certainly not my favorite small tree. Actually, in most situations, I rather dislike it, which is why I sometimes accidentally spell it without the first ‘e’. It is a cop out; a micro tree that too often ends up where a larger and more respectable tree would be more appropriate. They are not shade trees. They are not not big enough for freeway landscapes or to be street trees on wide boulevards. They are not immune to diseases and insect infestations; and they commonly drop honeydew from aphid or scale infestation, and lose their bloom to powdery mildew. They are not ‘low-maintenance’, and really should be pruned more than they are, but will get you in trouble with the neighbors if you prune them as aggressively as they should be pruned.
They are popular because of their potential for remarkably flashy bloom, and because they do not get big enough to damage the sidewalks and curbs that they are so often planted next to. ‘Gardeners’ like them because they survive their neglect. That is no long list of attributes; but there is one more.
FALL COLOR! On a bad year, they merely turn bright yellow. This year, some are this exquisitely bright orange with a slight red blush. The various cultivars display various colors, so some are more colorful than others. They are also on different schedules, so the most colorful are not necessarily the most colorful every year. Those that colored early are already bare, but could be the most colorful next year if the weather turns cold early. A bunch in town that are also defoliating as fast as they color because of the recent rain, could be the most colorful next year if rain is delayed later than it was this year.P81201K+

Six on Saturday: Too Much Autumn Color II – Natives & Exotics

 

Now we have a bit more variety than the last batch of six.

Red stem dogwood of the first and second pictures is the only species that is locally native. The California currant of the fourth picture, and the California black walnut of the fifth picture are both as native to California as the names imply, but are not native locally. The flowering dogwood of the third picture is from Eastern North America. You can guess the origin of the Chinese wisteria of the sixth picture, which happens to be the only vine represented in all four groups of six pictures.

The first three of the six pictures, or half, are of dogwood. The first two pictures are the only two in all four groups of six pictures that are the same species, namely red stem dogwood. Both were posted just to demonstrate that red twig dogwood, which typically turns only pale yellow like the foliage of the first picture, can develop a bit of red foliage like that of the second picture, if conditions are just so. Both the red stem dogwood of the second picture, and the flowering dogwood of the third picture, are the first two examples of red foliage from my four groups of six pictures. In the next two groups of six pictures, there is only one other example of bright red foliage, as well as an example of brown foliage, and an example of irregularly bronzed orange foliage. Those are topics for next week.

1. red stem dogwoodP81208

2. red stem dogwoodP81208+

3. flowering dogwoodP81208++

4. California currantP81208+++

5. California black walnutP81208++++

6. Chinese wisteriaP81208+++++

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/

Six on Saturday: Too Much Autumn Color I – Natives

 

The merely adequate color among the sweetgums early in the season suggested that color would be insipid this year. Then, the weather did something that set it all off. There was too much autumn foliar color this week to select just six pictures. So, I didn’t. These six are only the first of four groups of six. It would not be practical to post a group weekly for four weeks, particularly since some of the colorful foliage in these pictures was dislodged by generous rainstorms shortly after the pictures were taken. There will be very little foliage left by the time the last group of six posts. Instead, two groups of six will be posted presently, and the other two groups of six will be posted next Saturday, before they are two weeks old. I hope this does not violate any rules.

All six specie in this first group happen to be locally native. They are also all yellow, which is the standard color here. Regionally, there is not much orange or red. The thimbleberry in the first picture is rather pale yellow, but that is more color than it typically gets. Of these six, the thimbleberry is also the only species that does not grow as a tree, or a shrub like the hazelnut of the second picture. The hazelnut happens to be a Western hazelnut. The cottonwood happens to be a black cottonwood, although I would not know what distinguishes it from any other cottonwood. The sycamore is more specifically a California sycamore, which really is quite distinct.

1. thimbleberryP81201

2. hazelnutP81201+

3. cottonwoodP81201++

4. sycamoreP81201+++

5. boxelderP81201++++

6. bigleaf mapleP81201+++++

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/

Ornamental Grape

51202Boston ivy is not really ivy at all; but is more closely related to grape. Along with creeping fig, it is one of the two best vines for freeway sound-walls. It protects the walls from graffiti and muffles sound. Unlike creeping fig, which is evergreen, Boston ivy is surprisingly colorful through autumn. Unfortunately, it clings to whatever it climbs with holdfast discs, so ruins paint, stucco, and any other surface it gets a hold of.

Then there is ornamental grape, Vitis vinifera. It is about as colorful as Boston ivy, and can climb almost as aggressively to thirty feet, but lacks the damaging holdfast discs. It is nearly fruitless, which may seem like a waste of an otherwise perfectly good grape vine; but it will not make much of a mess until it defoliates. If any of the tiny fruit actually matures, it will almost certainly get eaten by birds before anyone notices.

Since it does not grip so tightly to what it climbs, ornamental grape can get rather shrubby. Outer growth can overwhelm and shade out inner growth, and can eventually produce a thicket of dead canes. Pruning back superfluous shrubby growth while bare in winter promotes more vigorous new growth the following spring and summer. Ornamental grape likes full sun exposure.

Sweetgum Color

P81117KWe may not get much foliar color in autumn here, but we get enough. Sweetgums do not need much cool weather to color well. They would probably have colored better and held their foliage a bit better if the weather got cooler faster, but we can not complain about what we got. Most of the crape myrtles are still completely green. Cottonwoods are defoliating, but without much color. Maples are rare here. The three best trees for color in autumn here are sweetgum, pistache and flowering pear. Of these, we happen to have several sweetgums here.P81117K+
Sweetgum is not the sort of tree that I would recommend for home gardens. They are innately very likely to develop structural deficiency. By the time such problems are identified, they are difficult to correct without disfigurement. Aggressive roots are likely to displace pavement, and sometimes invade septic systems. Then there are all those nasty maces; those hard and prickly round seed pods that stick into lawns and make pavement dangerous to walk on. They are too abundant and heavy to rake away as easily as fallen leaves. There are not enough squirrels in the entire forest to take them all!P81117K++
In some of our unrefined forested landscapes, where maces and falling limbs can fall into the forest without damaging anything, and roots can not reach concrete pavement, sweetgums can be allowed to go wild. (Unfortunately, most of ours happen to be near concrete within refined landscapes. That is another story.) Their tall and somewhat conical form happens to work very well with the native redwoods and Douglas firs, which provide the perfect rich green backdrop for their exquisite autumn color. Those of us who do not know better might mistake them for a native species. They look right at home here.P81117K+++