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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Why Autumn Is Also Fall

50923thumbNow that leaves are falling, they need to be raked. Large leaves, like those of sycamore and fruitless mulberry, can shade out lawn, shallow ground cover or dense shrubbery. If shade is not a problem right away, mildew can be after only a bit of rain. If abundant enough, finely textured silk tree or jacaranda foliage that typically sifts harmlessly through shrubbery and most ground cover, can accumulate and damage lawn, dichondra and the densest of ground cover. Walnut foliage has an herbicidal effect on sensitive annuals and some perennials.

Foliage is only beginning to fall. Cooling weather causes deciduous trees to shed more. Rain and wind bring the foliage down even faster. Even evergreen trees that naturally shed throughout the year will likely shed more through the upcoming wintry weather. Some trees start to defoliate early in autumn. Some hold their foliage until frost. Some trees that seem to be evergreen hold their foliage through winter, and then only drop their older foliage as it gets replaced by new foliage as winter ends.

Pavement and decks should be raked of leaves, not only to avoid staining, but also because rotting leaves can become dangerously slippery. Curbside gutters are too visible to get neglected for too long. However, heavy rain can quickly deliver to the cleanest of gutters a mess of fallen leaves as well as any other debris and litter that happens to be up the road. Strong wind can be filtered through hedges, leaving drifts of blowing leaves.

Leaves should also be cleared from roof gutters and downspouts, and may need to be cleared away again later in the season. More debris may need to be removed from awkward spots where it might accumulate, such as behind chimneys. Flat roofs may need to be raked.

There are a few exceptions to the need to rake fallen leaves. Where they get absorbed into coarse ground cover like Algerian ivy, falling leaves are generally not a problem. Pine needles and cypress foliage can be left if it happens to be useful for the natural suppression of weeds. Mature coast live oaks and valley oaks that are accustomed to a layer of their own fallen leaves over the surface of the soil actually want it to stay. For them, the foliar debris is a mulch that adds organic matter, insulates the soil, and retains moisture.

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.

First Color Of Autumn

P91013Okay; so this is neither the first, nor real autumn foliar color. It just happened to be convenient for me to get a picture of. Someone left this unfortunate Japanese maple right outside on the driveway a few years ago. It colors early from uncomfortable exposure to late summer warmth. The picture below is even more colorful, and was from even earlier in the year, last August.

Foliage that is starting to color here is nothing to brag about. Some of the older dogwoods leaves just shrivel and turn brown. I can only hope that enough newer foliage lingers to color as well as it did last year. Cottonwoods start to drop foliage while it is still green, but should eventually color to a subdued yellow before the last foliage falls. Sycamores are bland no matter how late.

There are only a few trees that reliably develop vibrant foliar color in such mild autumn weather, and only a few of such trees happen to be in our landscapes here. We lack Chinese pistache, flowering pear and ginkgo. The few sweetgum that are scattered about provide most of the foliar color here in autumn. It is still too early for them to color though. They need a bit more chill.

Flowering cherry and dogwood, which are uncommon just a short distance farther inland, happen do do quite well for us, and mostly color remarkably well in autumn. They only need a bit more time and chill. Birches are not as colorful, but are bigger and bolder, and eventually cover the ground below with delightfully yellow foliage. Boston ivy was added only earlier this year.

Native flora does not contribute much color. Bigleaf maple turns only a soft yellow. Poison oak turns rich deep red, but there is not much of it.P80819

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 IV – Uncategorized Exotics

 

These are the last six of the twenty four pictures of autumn foliar color that I got before the rain knocked so much of the foliage to the ground more than a week ago. #2 is the only picture of foliage that is on the ground instead of still suspended on the stems that produced it. The fallen birch leaves were just too pretty on the stone wall to not get a picture of them.

1. Japanese maple is not my favorite species, but it does have certain attributes. There happen to be several at work just because they happen to work well there. Some that do not typically develop good color got remarkably colorful this year. I believe that this particular Japanese maple is the common ‘Bloodgood’. It had been dark reddish bronze through summer, and then turned brighter red for autumn.P81222

2. European white birch is grown for the elegant white trunks that contrast so nicely against the deep green of the redwoods. This autumn foliar color, although brief, is an added bonus. These trees were already starting to defoliate before the rain.P81222+

3. Hydrangea is not known for autumn foliar color, and as you can see, turns only pale yellow. Yet, it is striking in the shade, and contrasts nicely with the rich green of redwood and English ivy foliage.P81222++

4. Spirea is likewise not grown for autumn foliar color, or at least no so much in our mild climate. There are more than a dozen of them here, and none are doing very well. They will get cut back and groomed now that they are bare. I do not know what cultivar this particular spirea is.P81222+++

5. Golden weeping willow was not only golden with autumn foliar color, but is still golden with the yellow bark on the twigs. So far, I am not too impressed with the yellow twigs. It is still a small tree, and growing in a mild climate that may not stimulate much color. Regardless, I happen to like weeping willows. This one happens to be in a swampy spot where it is quite happy.P81222++++

6. Bald cypress is rare here, but there happens to be two at work. One was supposed to be a dawn redwood, but was obviously mislabeled. Fortunately, it just happened to be planted on the bank of a small creek where it gets plenty of water. The other was planted in an area that is too swampy for other trees. Both are doing quite well. When they defoliated, they covered the ground with finely textured needles that would have been impossible to rake up.P81222+++++

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 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/