California buckeye, Aesculus californica, is an enigma. How does it survive while defoliated for so much of the year? Not all are so mysterious. Those that live in sheltered or forested situations behave like normal deciduous trees, by defoliating in autumn, and refoliating in spring, after a brief winter dormancy. Those that are more exposed in warm and windy situations make us wonder.
After their brief winter dormancy, exposed California buckeye trees refoliate early in spring, as they should. Then, only a few month later, they defoliate through the warmest and most arid part of summer, which might be a few months long! As the weather cools and the rain starts, they refoliate briefly for autumn, only to defoliate in time for their winter dormancy. They are ‘twice deciduous’.
How do they photosynthesize enough to survive? It seems like they would consume more resources in this process that they could generate. They obviously know what they are doing, since they survive quite nicely in the wild. Furthermore, they are not the only species that can do this. Sycamores sometimes do it if the weather is just so, or if they get infested with anthracnose too severely.
Most deciduous plants defoliate only in winter because that is the worst time to try to photosynthesize. There is less sunlight available while the days are shorter, and the weather is cloudier. Frost, wind and snow would cause much more damage if deciduous plants retained their foliage. Defoliation is how they accommodate the weather. It is no different for plants that defoliate in summer.
Much of California is within chaparral or even desert climates. Native plants, as well as plants that are from similar climates, know how to live here. If they happen to be in a hot and dry situation, some may go dormant until the weather improves, even if they do not go dormant through the mild winters. This is why wild arums and some unwatered acanthus have died back to the ground, and why naked lady amaryllis will remain naked until the first rains in autumn.
The weather in the parts of California that most of us are familiar with is generally rather mild. Some of the hottest temperatures every recorded were in the Mojave Desert, but not many of us even know how to get there. Some of the heaviest snowfall ever recorded was near Tahoe, but many of us think of that as almost Nevada. San Jose, Los Angeles and the most populous regions enjoy mostly comfortable weather throughout they year.
‘Drought’ is often an inaccurate description of the naturally prolonged dry chaparral and desert weather, as if it is abnormal. There would be no chaparral or desert if it rained here as much as it does in other climates. What is considered to be normal rainfall in some regions would be disastrous to regions that do not normally get so much precipitation. Drought does happen here sometimes, but it is not as common as outsiders believe it to be.
Once in a while, we get something that really is strange. The floods and mudslides of the Winter of 1982 were disastrous. The wicked frosts of late 1990 were the worst in recorded history, even though they would not have been much of a problem in most other climates farther inland. On the morning of December 1 in 2011, Pasadena and the surrounding regions of the San Gabriel Valley experienced historically strong and destructive winds.
When I went to Los Angeles shortly afterward, I was amazed to see that pieces of the glass facades of some of the skyscrapers had been stripped away. Thrashed fronds of queen palms hung limply as if a hurricane had gone through. My colleague got these startling pictures of destroyed Canary Island date palms, which are famously resilient to wind, in Leimert Park, about fifteen miles southwest of Pasadena.
This really is something that I did not expect to see. It may not look like much. It is just a raspy anemone with bites taken out of it, blooming later than it should. What is so impressive about it is that it was not planted here last year. It was planted during the previous year, then bloomed on time last year, and then died back like anemones normally do. I did not plant it, of course. It is in a planter where volunteers contribute whatever they like.
In case you are wondering why I am writing about it as if I did not expect it to bloom again, I didn’t. For whatever reason, anemones typically bloom well only once here, in their first season after they get planted. They may produce foliage for the following season, or maybe even several seasons, but very rarely bloom again. It annoys me that they are even sold locally. Nurseries should no better than to sell bulbs that do not perform well here.
I have always believed that anemones, like a few other types of bulbs, do not get enough chill in winter to bloom again. This is a rather mild climate. There are certain cultivars of apple that do well where winters are cooler that would be dissatisfied with the minimal chill they would get here. (Incidentally, this last winter was not unusually cold.)
There is also the possibility that anemones can not maintain their foliage long enough through the arid spring and summer weather to sufficiently regenerate their resources to bloom again. The foliage begins to appear in conjunction with bloom, then grows more as bloom finishes, but then dies back as the weather gets warm in spring and summer. The weather is not hot here, but it is rather arid.
It may not look like much, but before all the rain started, the San Lorenzo river was shallow enough here to walk across. The water was clear and barely flowing. It is impossible to guess how deep it is now. It looks like cafe au lait, and is certainly flowing better than it had been. The watershed is less than a hundred and fifty square miles, so all this water is not coming from very far away.
The first picture above, of the San Lorenzo River flowing south to Santa Cruz and the Monterey Bay, was taken from the western of the two windows on the south side of the Felton Covered Bridge. Experts believe this to be the best of the four windows. My Mother has an old black and white picture of my older sister, my younger brother and I looking out from this window when were just little tykes. There was a railroad bridge out there a long time ago. Only concrete foundations remain.
The second picture below, of the San Lorenzo River flowing from the Santa Cruz Mountains beyond, was taken from the western of the two windows on the north side of the Felton Covered Bridge. The San Lorenzo River flows south on this side too!
It has been raining rather well here. Boulder Creek, which is at the far north end of the San Lorenzo Valley, gets more rain than most places in California, and far more than the rain shadow region on the inland side of the Santa Cruz Mountains. Local rain does nothing for the water supply of the rest of California, but is a good indication that snow is falling in the Sierra Nevada, where most of the water for much of the rest of California is stored in the snowpack.
What is this? It looks more like hail now. It was softer and squishier when it fell out of the sky only an hour or so before this picture was taken. There was a slight bit of snow up on Summit above Los Gatos. It will probably melt as quickly as the clouds clear to let the sunlight through. Snow sometimes appears on the higher peaks around the region, but is rare in lower elevations. Forty three years ago from today, on February 5 in 1976, snow fell in the Santa Clara Valley. It was about half an inch deep in some areas, an inch and a half in others, and was the last snow to fall there.
It was one of the more common types of snow in the Santa Clara Valley in the early 1970s.
In school, we made paper snow by folding paper squares in half and then into thirds (so that they were folded into sixths), and then cutting notches and slices out of them. They unfolded into the prettiest and laciest snowflakes!
In Westgate Mall, snow was blown by small fans about the new models of Singer sewing machines that were magically suspended in big acrylic spheres. We children could not get into the spheres, so were left wondering if the snow within was as cold and wet as we were told it was, and why it was necessary to demonstrate that the new sewing machines were resistant to weather. Our mother did her sewing inside.
We sort of suspected that the snow around the Nativity at Saint Thomas of Canterbury and other local parishes might be artificial because it looked like the stuffing of a pillow, which is something that all children seem to be familiar with. We said nothing about it, just in case our parents were not aware of the potential deception. However, it was rather disturbing to see so much of the same sort of snow at Christmas in the Park in San Jose. At that point, we accepted that either it must be genuine, or that we were committed to just going along with it.
Snow that was sprayed onto Christmas trees was rather interesting. It was neither wet nor cold, and sometimes it wasn’t even white. It could be pastel blue or pink, and was often sparkly with glitter! Wow!
Off in the distance, we could see snow on top of Mount Hamilton. Sometimes it was just on top. Sometimes, it was spread out from left to right, along the ridge. On rare occasion, snow appeared on the ridge of the East Hills, in front of the Diablo Range that Mount Hamilton is part of. We never saw who was up there folding and cutting all that snow, but they must have been VERY busy!
Snow on top of the Santa Cruz Mountains, right behind our part of the Santa Clara Valley, was closer to home, but did not look like much. The greenish blue of the forest was just a lighter hue of blue, with more mottling. It was exciting anyway.
Then, on February 5 in 1976, it actually SNOWED on the floor of the Santa Clara Valley!
It really was as awesome as snow was supposed to be. It was cold. It was wet. It was white. It was fun to wad up and throw at each other. It accumulated just like it would in a blizzard, and got almost an inch deep!
. . . but . . . was it really SNOW?
We are now two days into it. Is it any different than three days ago, the last day of autumn? Not really. Even in harsher climates, the changes from one season to the next are gradual. Like the phases of the moon, the seasons are constantly phasing out of the previous, and into the next. The dates of the first and last days of each season, which are determined by the position of the Earth within its orbit around the sun, are technicalities.
Seasons in the Southern Hemisphere are of course opposite of what they are here. That seems odd to me. The calendar is the same there as here. It seems obvious to me that winter and all seasons should be determined by the same dates there that they are determined by here. If winter began last Friday here, it should have done the same there, on the the same date. Longer days and warmer weather are consequences of location, south of the Equator. It is hard to imagine that January and February are summer there.
It also seems odd to me that all maps are oriented with North directed towards the top. Shouldn’t South be at the top South of the Equator? Must Australia be the ‘land down under’ to those who live there? Things would be so much simpler if Columbus has just stayed home, and the World was still flat.
Anyway, we do not get much winter here. The weather gets a bit cooler, and we will eventually get more rain. When I went to Oklahoma six years ago, I thought that I would finally get to experience a real winter, but we left just before New Year’s Day, while the weather was still somewhat mild. This little bit of snow was about all we got.
Red sky at morning; sailor take warning. Stormy weather is to be expected.
Back before modern meteorology, there were all sorts of ways to predict the weather. Some of the ways to know what to expect in the short term were obvious, such as simply observing what was happening off in the distance in the direction from which the weather comes. For the experienced, it is easy enough to feel changes in humidity and temperature in an incoming breeze.
Halos around the moon or sun, as well as the color of the sky at sunrise, provided a bit of insight about what could be expected a bit farther out than the short term. Some techniques were not always accurate, and some were not accurate at all.
Flora and fauna are better at predicting the weather than we are. Horses, dogs and cats get extra fluffy if they expect the winter weather to be colder than it normally is, and they shed early if they expect an unusually warm summer. Sycamore trees are so responsive to the weather that what they are saying about it is not always obvious. Are they browning and defoliating just because the weather got too hot and arid late in summer, or because autumn is going to be extra cool? Experts could tell, but because of modern meteorology, there are not many experts left here.
This red sky over Mount Hermon occurred at sunrise last Sunday, just prior to the storm that finished early Monday morning, and provide picture #6 for my earlier Six on Saturday post. I tried to avoid the streetlamp at the bottom of the right edge. I did not see the bird when I took the picture. The tree to the left is a golden honeylocust.
We do not get much frost here. This picture of the view through the windshield of one of the work vehicles was taken more than a week ago, while the humidity and the temperatures were still quite low. The sparse and angular pattern of the frost on the windshield is a result of the minimal humidity. There will be more frost later in winter, although there will not be nearly as much as most other climates get.
After a cool Monday morning last week, the weather got a bit warmer, or really just less cool. Rain started about midnight between Tuesday and Wednesday, and continued through the day and into the night. More rain is predicted to start after noon next Tuesday, and continue through Thursday. There will be no frost during this weather pattern. Frost happens here only between rainy weather. One might think that since we do not get much rain, there would be plenty of time in between for frost. Really though, much of our winter weather is simply quite pleasant, neither rainy nor frosty.
As appealing as this might be to those in harsher climates, it has certain disadvantages.
So far, there was just enough chill to start defoliation of the black locusts and box elders in the background of the picture, and just enough rain to almost finish it. Trees that need more of a chill to start this process are not so impressed with the weather. Many of the crape myrtles have not even started to color yet. Cottonwoods are starting to defoliate, but are doing so while still only dingy greenish yellow because they did not get enough chill for better color.
Spring bulbs that got planted earlier or are being planted about now will bloom next spring because they were so optimal and primed to do so before they were planted. However, many will not get enough chill in their second winter to bloom again. Consequently, many of the bulbs that would be perennial in other climates are grown as expensive annuals here. Likewise, seed of certain specie that self sow may not get enough chill through winter to germinate next spring.
So again, what is comfortable for us is not so ideal for everything in the garden.
Is it coming or going? Autumn that is. It normally gets here last. We are typically only beginning to see the first foliar color of autumn while other parts of America get their first snow. We typically get a few more tomatoes out of our vegetable gardens long after most everyone else has pulled out their frosted tomato plants.
Well, we still got it. Tomatoes that is. The plant that produces these bright orange cherry tomatoes is looking a bit tired and pale, but the tomatoes are as good as ever. It probably will not last until frost. The plant might get pulled out when the tomatoes run out. Without bloom, that could be pretty soon. Frost does not happen until well into winter. Regardless, tired tomato plants say that autumn is coming.
We got foliar color too. This Japanese maple turned this nice garnet red quite some time ago. Sweetgum trees all over town are also well colored. They seem to be ahead of schedule, as if winter is on the way. Defoliating black oak trees say that autumn is going.
While the days are still pleasantly warm, with temperatures into the 80s, the nights get cool enough to color deciduous foliage. Warm days are quite normal for this time of year. So are cool nights. However, the two typically do not happen together for more than a few days. Warm days typically alternate with mild nights. Cool nights typically alternate with cool days.
Well, even in our mild climate, the weather is always full of surprises. We will enjoy it while it lasts. Autumn has always been a mere in-between season anyway. In the chaparral and desert climates of California, winter and the rain that comes with it will be welcome when they arrive.