Six on Saturday: When It Rains, It Pours


The frequency and duration of rainy weather here is not very much more than in the rain shadow where the inland base of the Santa Cruz Mountains merges into the Santa Clara Valley. However, the volume is about triple! My former neighborhood in town just about fifteen miles away gets about one foot of rain annually. The average annual rainfall here is about three feet.

That extra two feet sometimes seems to fall all at once.

1. Rain got heavy enough for me to bother recording this first of six brief videos. I do not know why the lights upstairs were pulsating and blinking. The downspout seems to be jet propelled.

2. This was certainly more than I expected. Off to the left, there were only two sandbags to put in front of a doorway that is three sandbags wide. This was a major problem. I did not panic.

3. Now I panicked. I called for help, but my radio was too wet to operate. There was nothing anyone could do anyway; or so I thought. I stopped the camera and went upstairs to investigate.

4. Removal of debris from the grate over this drain fixed everything fast. This was more than I expected too. We all know that this drain is partially clogged. The water and hail was freezing!

5. Within a minute or so, the water drained away surprisingly efficiently, leaving this icy mess on the small patio between the two stairways. It was like a Slurpee mixed with redwood debris.

6. More of the grungy Slurpee remained on the lower patio outside the doorway that lacked adequate sandbags. Water barely crossed the threshold to dampen a few square inches of carpet.

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


P00101-1January 1, 2020! The first day of the Twenties!

The flora in our gardens north of the Tropics must think we are crazy for making such a fuss about it while they are trying to sleep. Even flora south of the tropics does not understand. All flora everywhere is more concerned with how the seasons change according to the position of the Earth around the Sun. Precise dates, times and numbers are meaningless.

It sort of seems odd to me that within each time zone, it is the same time and date both north and south of the Equator, but the seasons of each side are opposite. Today started in sparsely populated regions of the Pacific Ocean, worked its way through Australia earlier, and is somehow still the same ‘today’ that is here now. Yet it is winter here, and summer to the south.

Now, if January can be in the cool time of year here, and the warm time of year in Australia, it seems to me that winter could be both the cool season here, and the warm season in Australia. If the dates are the same, it seems like the seasons should be too. Alternatively, if the seasons are half a year early or late in opposite Hemispheres, it seems like dates should be too.

According to such logic, it could be either winter or July 1 in Australia and elsewhere south of the Equator right now! . . . But would that be July 1 of 2019 or 2021? Too many technicalities!

Well, it is more than the flora in the garden is concerned about anyway. It is winter here now, and summer south of the Equator. It is the beginning of January everywhere that the Gregorian calendar is used, north and south.


Note: ‘Horridculture’ will resume next Wednesday. It did not seem appropriate for the first day of 2020.P00101-2

Rain Shadow

P91222Hollywood is famous as the Cinema Capital of the World. Niles was its predecessor. Both are within regions of remarkably diverse scenery that is so important to cinema. Mountains, deserts, chaparrals, forests, lakes and big cities are conveniently nearby. There are not many places in the World with such a thorough mix of geography and climate. California really does have it all.

It is a challenge for gardening though. The stone fruits that grow so naturally in the Santa Clara Valley are not quite as productive just a few miles to the South in the Santa Cruz Mountains. The pears and apples that do so well in the Santa Cruz Mountains are not quite as happy in the Santa Clara Valley. Species that want a good chill in winter do not want to be in Los Angeles.

On the coastal side of the Santa Cruz Mountains, just outside of Felton, a few days of rain filled the bin in the picture above. The rain continued just as long throughout the area, including the inland side of the Santa Cruz Mountains and the adjacent Santa Clara Valley. Although the duration of the rain was approximately the same, the volume of precipitation was very different.

The water in the bin is more than a foot deep. That is about the average annual rainfall for my former neighborhood at about this same elevation, but on the opposite and inland side of the Santa Cruz Mountains. Storms must drop much of their moisture to get up and over, but are then able to retain much of the remaining moisture as they drop in elevation on the other side.

The drier inland side of the Santa Cruz Mountains, and adjacent portion of the Santa Clara Valley are in what is known as a ‘rain shadow’.

Rainy Season



As I mentioned this morning, the first storm since spring delivered a bit more than an inch and a half of rain before dawn on Wednesday, ending the fire season. The second storm is here right now. It is expected to be followed by a continuous series of storms that will provide rain through Monday, showers through Thursday, more rain on Friday, and showers . . . forever!

It is now the rainy season.

The video above shows what rain does. It gets things wet. It is, after all, composed of water. It falls mysteriously from the sky, which, as you can plainly see, is occupied only by a mostly monochromatic gray cloud cover. Seriously! There is nothing else up there. There is no one on the roof with a hose or anything of the sort. All that water just falls from the cloud cover above.

I could not get video of individual raindrops falling. They are too small and too fast. Only a few can be seen indirectly in the video, falling in front of the water cascading from the rusted out gutter. The spots on the video are raindrops that landed on the lens, so were no longer so animate. The cascading water is, of course, an accumulation of many raindrops that fell on the roof.

Besides ending the long fire season, rain also disrupts the slim fall color season, when foliage of certain deciduous trees turns color as the weather cools in autumn. There is not much to brag about anyway. Only a few native trees are moderately colorful. More colorful exotic trees are not very popular because they do not color as well as they do where autumn weather is cooler.P91130K

Before the rain, these birches were a nice clear yellow, but were already defoliating. Their fallen leaves were as pretty on the ground as they were in the trees, but unfortunately needed to be blown. By now, there is likely more on the ground than there is in the trees, but it will need to be blown too. At least it gets to stay on the open ground in the rest of the casual landscape.P91130K+

The only tulip tree here got cool enough to defoliate before the birches this year, but not quite cool enough to color well first. It is a grand tree nonetheless. We do not expect exemplary color in autumn in our splendidly mild climate anyway. The sweetgums will compensate. They are only beginning to color, and should hold some of their foliage rather well through the weather.P91130K++

Almost RAIN!

P91123KThere have been only three hints at precipitation since last spring.

The (sideways) picture above shows the same dampened hood of a Chevrolet that provided the illustration for a post on another blog on September 30.

The picture below shows a similarly dampened but different windshield from that which provided the illustration for a post on November 16, regarding a bit of precipitation two days prior, on November 14.P91123K+

All four pictures here were actually taken just after a very brief rain shower that happened just after midnight on November 19. I tried to be artistic with them, but I am not a photographer.

The picture below demonstrates how difficult it is to hold the camera steady while getting a close up picture of rain dripping from a lumber rack at night. Do digital cameras automatically extend exposure to accommodate for the darkness? Is it blurred or merely ‘abstract’?P91123K++

The rain shower was very brief, lasting only a few minutes, but dropped dozens of individual raindrops, maybe more than a hundred! In fact, there were enough of them to collectively flow from one of the roofs, accumulate in a gutter, and flow down this downspout and onto the pavement below! (I really do not know why a diverter is needed on pavement, but there it is.)P91123K+++

I bet that if all the precipitation than fell from the sky during these last three incidents could have been collected, there would have been more than a pint! As excellent as it was, it was not even the best of it. For the first time since last spring, a storm is predicted to move in and start RAINING about noon on Tuesday, November 26! Showers should continue afterward.

The rainy season will likely begin with this first storm. That is how the weather typically operates here.

Autumn Weather Prompts Foliar Color

91127thumb(alternate)Mild climates allow more flowers to bloom through autumn and winter here than in most other parts of America. That is why cool season annuals like pansies and violas are so popular. Cyclamen can be planted now too. None will be obscured by snow. By the time cool season annuals start to fade, warm season annuals will be replacing them. There is something to bloom in every season.

There are a few disadvantages to mild climates, though. Many plants rely on significant winter chill to stay on schedule. Inadequate chill limits the cultivars of apples and pears that are productive here. Not many spring bulbs will naturalize. Prior to winter, some deciduous plants are hesitant to resign to dormancy until they experience a chill that is cool enough to convince them it is autumn.

Some deciduous plants recognize a specific temperature as credible evidence of a change of seasons. Others want a specific temperature to be sustained for a specific duration or repeated for a few nights. Shorter days and longer nights are taken into consideration by species who want to confirm what they deduce from the weather. Different plants use different methods of observation.

That is why deciduous plants who develop foliar color before defoliating in autumn do so on their own terms. Weather conditions that promote excellent color among birches may not be the same that cause flowering cherries to color well. Warmth and minimal humidity that sometimes prompt premature and blandly colored defoliation of sycamores might enhance later color of sweetgums.

Sweetgum, Chinese pistache, flowering pear and ginkgo are the most reliable trees for foliar color in autumn. Ginkgo turns only brilliant yellow. The others exhibit an excellent mix of yellow, orange and red. Crape myrtle can be about as colorful, but is not always as reliable.

Of course, there is more to these and other deciduous trees than their colorful foliage in autumn. After all, they are trees. Their particular characteristics and appropriateness must be considered before adding any of them to a landscape.91127thumb

Not Quite Rain

P91116KMost of us here agree that the minimal bit of precipitation that fell from the sky on Thursday was not real rain. There are a few different theories about what it actually was though. It could be considered to have been drizzle. It alternatively could have been heavy fog or mist. Some of us make up silly names for what it was, such as fine rain, dusting, spritzes, sprinkles or mizzle.

Is it just me, or do those last three sound like inane kitten names? ‘Dusting’, sounds dirty and dry, which it was not.

Whatever it was, it was the second occurrence of such precipitation since the rainy season ended last spring. Something similar happened on the last day of September. I wrote about it in my other blog, with a picture of it on the hood of a parked car, rather than the windshield. I think it was more of a surprise then because it was earlier, and the chance of precipitation was slim.

This weather pattern is still within what would be considered normal here. The rainy season typically starts a bit earlier, even if with just a single primary storm passing through, followed by a long pause before more follow. There is no strict schedule though. We know that the rain will eventually start, and that rainy seasons that start late tend to provide significantly more rain.

Rain is likely just as uncomfortable here as it is everywhere else. Perhaps it is even dirtier, because it rinses off dust and crud that has been accumulating since spring. No one wants to work in their garden while it is wet. Nonetheless, because there is no rain for nearly half the year, the first storm of a season is something to be celebrated. The forecast predicts no celebration yet.

Mediterranean Climate Is Something Special

90925thumbThe climate here is pretty cool, at least in winter. Right now, it is pleasantly warm. It does not often get uncomfortably cold or hot, and when it does, it does not stay like that for too long. In between the warmest days of summer, the nights typically cool off nicely. In between the coolest nights of winter, the days typically warm up nicely. Humidity is normally minimal. Rain is adequate in season.

We have here what is known as a ‘Mediterranean’ climate. Obviously, it is similar to many climates of the Mediterranean Basin. Beyond the Mediterranean region, there are not many other places in the World that enjoy such reliably temperate weather. Most of such places are in southern and southwestern Australia, the Western Cape of South Africa, central Chile, and evidently, right here.

This particular region of Mediterranean climate is quite large, and extends into northern Baja California. Native plants know how to live here, and many of those that are adaptable to landscapes and home gardens can survive quite nicely with little or no irrigation. Some exotic (non-native) plants want climates with more warmth in summer, more chill in winter, or more rain through the year.

The best, as well as the worst, exotic plant species for local landscapes are those that are native to other Mediterranean climates.

The worst are those that are so happy in the local climate that they naturalize and become invasive to native ecosystems. Without pathogens or competing species that inhibited their proliferation within their respective native ranges, many naturalized species are detrimentally aggressive in ecosystems that they invade. Pampas grass, broom and Acacia dealbata are familiar examples.

The best exotics are not so threatening. Australian fuchsia, kangaroo paw, coprosma, westringia, bottle brush, grevillea, dracaena palm and eucalyptus originated from Australia. Lemon verbena, mayten and some salvias are from Chile. African iris, lily-of-the-Nile, bird-of-Paradise and all of the aloes came from South Africa. Olive, oleander, cistus, and all the lavenders are Mediterranean.

Summer Dormancy Is No Mystery

90821thumbCalifornia 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.

Pasadena Windstorm


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.