Automated Irrigation Should Adjust To The Weather.

Some irrigation becomes temporarily obsolete through the rainy season.

Now that it has started to rain, what should be done with automatic watering systems? In almost all situations, automatic irrigation systems should be adjusted to accommodate for moisture provided by rain. If rain is sufficient to provide enough or too much water, irrigation can be discontinued until needed again when the rain stops a few months from now.

If the first few storms are discontinuous enough with warm and dry weather mixed in between, lawns and plants that want more substantial watering may need to be watered a few times until the rain becomes more reliable. However, because of cooler temperatures and shorter days, plants do not use nearly as much water as they did during the summer anyway, so do not need to be watered nearly as much as they were only a month or so ago.

Deciduous plants that are losing their leaves need the least moisture, since they can not lose any moisture through evapotranspiration (evaporation from foliar surfaces). The very few plants that bloom or even start to grow during winter use a little bit more water than those that really are dormant, but are still likely get all they need from rain even without getting watered.

Flowering annuals, particularly left over warm season annuals that continue blooming late, may get moldy with too much rain. Their flowers and some of their foliage can turn to mush until there is a break in the rain. Removal of damaged flowers and leaves slows the spread of the mold but does not cure it. Good air circulation among well spaced plants and in exposed areas helps inhibit mold. Regardless, moisture from abundant rain can eventually cause mold to be a problem.

In fact, the only plants that are not likely to get all the water that they need from rain are those that are in pots and planters under eaves or in the home as houseplants. Nonetheless, sheltered plants that are outside should still get much less water now than they do during the long and warm days of summer. These plants are either dormant or at least more sedate because of the shorter cooler days through winter. Houseplants may likewise use less water because the home environment is also cooler.

However, if the heating system of the home decreases humidity, some large houseplants may actually want a bit more water through winter! Humidity fluctuates most in older deficiently insulated homes that are heated by wood stoves or fireplaces; since these homes get humid without a fire burning, but then get much drier with a fire. 

Six on Saturday: Attempted Autumn

Astronomical autumn began more than a month ago. It is about a third done, with about two thirds remaining. Meteorological autumn can start at any time. Sometimes, it starts, but then pauses before restarting a bit later. Sometimes, the first rain is the beginning of the rainy season, which typically continues through winter. A bit of rain arrived between Wednesday and Thursday, and a bit more is here now, but no more is in the forecast for next week. Regardless of future weather, some flowers bloom, or at least try to, as late as they possibly can. Of course, some actually prefer to bloom even later and during winter. Apologies for the lack of focus of pictures #4 and #6.

1. A ‘chance or rain’ in the weather forecast here is generally not taken too seriously until something like this happens. It is a genuine puddle. It is wet, and full of water from rain.

2. Sequoia sempervirens, coastal redwood seems to enjoy this damp weather. It actually enjoys all weather, but appears to be more refreshed by any interruption of arid warmth.

3. Lemna minor, duckweed is even weirder with this border of white foam that develops as the first rain washes away pollen and dusty crud that accumulated since the last rain.

4. Hedychium coccineum X coronarium ‘Peach Delight’ ginger lily, which was blooming for last Saturday, is trying to bloom again. I already doubted its ability to follow through.

5. Brugmansia X cubensis ‘Charles Grimaldi’ angel’s trumpet looks like Carl’s Junior ate too much of its own food. I added this because of response to angel’s trumpet last week.

6. More interestingly, it produced this seed pod. Such hybrids should be sterile. I can not help but wonder if seed is true to type. If so, propagation by cuttings is easier than seed.

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/

Irrigation Resumes With Drier Weather

Spring gets progressively drier and warmer.

Spring, in several regards, is like autumn in reverse, or vice versa. Bloom increases for spring but decreases for autumn. Foliage increases for spring but decreases for autumn. The two seasons are in opposition. In this chaparral climate, the rainy season that began last autumn ends now. Irrigation that became redundant then becomes necessary now.

Diminishing rain is not the only reason that irrigation becomes more important for spring. Spring weather also becomes warmer and more arid, or less humid. Warmth and aridity increase evaporation of moisture that rain deposited not long ago. Increasing day length, intensifying sunlight and warmth accelerate plant growth. Such growth consumes water.

This need for moisture is progressive, though. Vegetation certainly requires more water as the weather becomes warmer and drier. However, it does not yet require as much as it will require later during summer. By then, the weather will be even warmer and drier, and the days will be even longer. Irrigation should increase accordingly in regard to weather.

Unfortunately, there are no simple formulas to determine how much irrigation is needed. Some vegetation with shallow roots may require frequent but moderate irrigation. Some vegetation with deep roots may prefer less frequent but more copious irrigation. Rain is possible at any time. It can briefly interfere with the most efficient of irrigation schedules.

Soil also affects irrigation. Sandy soils drain efficiently, but do not retain much moisture. This may not be a problem for some species that tolerate occasionally dry soil. It may be more of a concern for species that prefer more regularly moist soil, though. Dense soils retain more moisture, but do not drain as efficiently. Soil amendments can improve soils.

Manual irrigation is easier to monitor than automated irrigation, but can be tedious. That is why most irrigation is automated nowadays. Automation is more likely to be excessive than insufficient. Desiccation, wilting and other symptoms of insufficiency of irrigation are obvious. Symptoms of saturation may not become obvious until too late for remediation.

Horridculture – Rainy Days and Mondays (deferred from Wednesday)

Deferred maintenance has consequences.

Karen Carpenter famously said, “Rainy days and Mondays always get me down.”

Several old and deteriorating box elders on the roadside outside the gate at work have survived many rainy days and many Mondays during the past many years that they have grown there. Earlier this week though, a rainy Monday brought one down.

It was no surprise. All of the several box elders there are in very bad condition. Most are completely dead and collapsing. However, I can do nothing about them because they extend over the roadway. They must be removed by a County Crew who can remove them safely. Unfortunately, they are unable to do so in a timely manner while so much similar work is needed throughout the County.

The problem with the demise of this particular tree is that it fell onto the hood of a Ford F150 that was travelling toward town. The Ford swerved and collided with a Subaru station wagon of some sort that swerved off the other side of the road, where it seemed to stop just inches from a utility pole. The tree or portion of the tree that fell was not very big, but indirectly caused extensive damage to both vehicles, and necessitated lane closures while the vehicles were removed.

In the picture, which was taken as I opened the gate for the crew, the Subaru is still visible on the opposite side of the road, at the center of the picture. The Ford has already been removed to the side of another road that extends to the right in the distance, beyond the bridge, where the traffic signals are. The taillights belong to one of the responding Sheriff’s cars. Most of the debris from the fallen box elder has already been pushed into the ditch to the right.

Rainy Weather Begins With Autumn

Weather changes with the changing seasons.

Rain is at least as relevant as temperature is to the seasons here. Temperature does not change as much. The warmest of summer weather does not seem to be terribly hot. Low humidity helps. The coolest of winter weather is not too terribly cold. Some local climates lack frost. The difference between dry weather and rainy weather is much more obvious.

After all, rainy weather ends during spring, and does not resume until about now. Almost no rain occurs during the extensively arid summer season. This includes late spring and early autumn. Summer thundershowers are uncommon. Therefore, almost all rain occurs during winter. Some also occurs somewhat variably during late autumn and early spring.

This is quite normal for local chaparral climates. Comparatively to other climates, it might be both an advantage and a disadvantage. It is why most landscapes, particularly lawns, rely on irrigation. It is also why the growing season is so long here. This climate provides more pleasant weather to facilitate more gardening. It also necessitates more gardening.

Recent rainy weather is likely the beginning of the rainy season. If so, it is obviously also the end of the dry season. Transition from one season to the next is not on a very precise schedule, though. Dry weather could potentially resume for a while. Conversely, El Nino has potential to promote rainy weather. This winter could be even rainier than last winter!

Even if rainy weather does not resume for a while, irrigation requires seasonal reduction. This includes frequency and duration of automatic irrigation. Vegetation consumes much less moisture while dormant through winter. Less moisture evaporates from soil while the weather is cool. Rain may provide most of the garden with more moisture than it can use.

Unfortunately though, rain is also potentially messy. It makes soil muddy, and can cause erosion. It dislodges deteriorating deciduous foliage, especially in conjunction with wind. Colorful deciduous foliage is much less appealing on pavement or lawn than in its trees. Raking fallen leaves, and all other gardening, is less pleasurable during rainy weather of autumn.

End of Fire Season

Burned trees are visible on ridge tops within the CZU Fire zone.

Rain is gratifying at the beginning of the rainy season. We all know that it has potential to become excessive later in the season, but we are not yet concerned with flooding or mudslides. After a typically long and dry summer, we enjoy it while we can. A storm that finished earlier yesterday was relatively minor, but was nonetheless the first significant storm of this new rainy season of 2023 and 2024. Only minor drizzle preceded it.

The beginning of the rainy season is also the end of the fire season. Forest fires become less likely as the forests become more saturated through the season. However, rain also sustains growth of vegetation that will become combustible during the following fire season, especially if the weather becomes unusually warm and arid by then. Unfortunately, this is the natural pattern of the climate here. Fire is a major component of local ecosystems.

Three years ago, the CZU Fire was the most destructive forest fire within documented history of this region. Larger fires likely occurred prior to documented history, but burned forests that expect to occasionally burn, without damage to unnatural infrastructure that did not exist at that time. Prehistoric fires were likely less common than modern fires, but involved much larger areas. They also likely burned faster and less violently. Modern forest fires involve more fuel because of regeneration of hardwood species after clear cut redwood harvesting a century ago. That is why so many coastal redwoods that survived several fires during their long lives succumbed to the CZU Fire.

Much of the marginal area of the CZU Fire is regenerating efficiently enough to eliminate evidence that it burned so recently. The scenery of areas that burned more severely remind us why we are grateful for the beginning of the rainy season.

Early Rain

This could be a sequel to ‘Late Summer’ from yesterday. It happened shortly afterward. It certainly adds another interesting component to this already odd year of weather. Although not impossible, rain at this time of year is rare. Almost all of the rain here occurs between late autumn and early spring.

Weirdly, if rain does occur during summer, it typically does so around the fifteenth of August. Seriously, it is very prompt about that schedule. It typically either begins or ends on that same date.

The first flash of lightning of the storm that started the CZU Fire occurred at 11:59 p.m. on the night of the fifteenth of August of 2020, less than a minute prior to midnight. So, although the storm occurred during the early morning of the sixteenth, it technically began on the night of the fifteenth.

This brief rain shower was minimal, but by local standards, it was surprising. I sort of wanted it to continue long enough to dampen and contain the dust of summer. It might have done so briefly, but could not prevent the dust from becoming dusty again shortly afterward. The aroma of damp asphalt dissipated even before that happened. It was fun while it lasted.

Perhaps this rain shower will be the last of this unusually autumnish weather. Warm and dry summery weather typically resumes immediately after brief rain showers that happen during the middle of August. Technically, for a summer rain shower, it is only half a month late. So far, the forecast does not suggest that pattern, but it has been wrong before, even here. I doubt that there will be any more rain prior to autumn, even if cool autumnish weather resumes until then. But of course, I have been wrong more often than weather forecasts.

Late Summer

Such weather is early this year.

The change of seasons can be boring here. It might seem as if this climate experiences only two seasons. Summer is the primary season, which seems to extend through most of the year, with what seems to be merely a few days of another brief secondary season which is not summer. Perhaps this brief secondary season is autumn, winter and spring, but that is too many letters and big words for such a small season.

That is how those who are familiar with more distinct seasons might perceive seasons of this innately mild climate. Those of us who are familiar with this climate perceive it quite differently. We are aware of the four seasons, regardless of how mundane the transitions between them seem to be. In fact, some might contend that, if autumn seems to be minimal here, it is merely because this climate experiences a fifth season between summer and autumn, which is known as Indian summer.

Indian summer is an extension of summery weather into autumn, and sometimes occurs after summer seems to have begun to succumb to autumn. It does not happen annually, and does not seem to be happening this year, but certainly could. It is sneaky that way.

For now though, autumn seems to be sneaking into the last two weeks of summer, much like Indian summer sometimes sneaks into autumn. Nights have been interestingly cool. Low clouds have been lingering a bit longer after sunrise than they typically do.

However, vegetation that enjoys warmth does not seem to be decelerating for cooler weather. Perhaps such vegetation knows more than the rest of us do about what to expect. Perhaps it is merely more responsive to photoperiod than weather. Regardless, I get the impression that this is how late summer typically is within other climates.

Hurricane Hillary

Rain is expected to start about six or seven in the morning in Brent’s neighborhood.

California is so big that, from here, it extends about four hundred miles to the north and four hundred and fifty miles to the south. That is where San Diego County is, in the southwestern corner of California. It is so far away that the weather there can be very different from here, as it is now that Hurricane Hillary is coming up from the coast of Baja California. While a tropical storm warning is in effect there, typical summer weather is expected here.

Typical summer weather here is dry. Not much rain happens after early spring. Not much happens prior to late autumn. Every few years, a single odd and brief thunderstorm goes through in the middle of summer, leaving no evidence of its downpours two days later. If it were to happen this year, it should happen about now, like it is in Southern California.

Forecasts for the weather in Southern California are quite unpleasant. A friend in Palm Springs was filling sandbags today. Floods and mudslides are expected through a huge area. This is the first tropical storm in California since 1939, and the first ever tropical storm warning. Yet, we will miss it completely here.

I try to remind myself that the historically torrential rain of last winter was no fun. Flooding was a mess, and caused significant damage even in this neighborhood. Nonetheless, even native Californians can start to miss rain late in summer.

Brent will likely telephone at about seven in the morning. It might be raining by that time. It should finish by noon on Monday. Realistically, it will not rain for long. The problem is that rain will be torrential, especially at high elevations out in the deserts, which do not absorb much water. It will be interesting to see what transpires.

Shasta Lake

Shasta Lake is a large reservoir on the Sacramento River. It contains water for flood control and to generate electricity. Some of the water within is used for agricultural irrigation and, to a relatively minor degree, to supply regional municipal water.

It is a very common misconception that the volume of water within Shasta Lake is necessarily relative to ‘drought’ conditions. Low water level is supposedly indicative of a ‘drought’. High water level is supposedly indicative of ‘normal’ weather conditions, including adequate precipitation. This same misconception seems to apply to all reservoirs in California.

Well, after the rainiest winter since 1982 and 1983, Shasta Lake is still not full. The level fluctuates, so might have been full earlier, or might be full later, but regardless, is not presently full. Water must be released prior to expected rainy weather, which can still occur during spring, in order to accommodate more water to control flooding. Less water may be released as drier weather is expected. Shasta Lake could therefore be fuller or completely full for summer, when almost no rain is expected. The presently observed water level does not indicate deficiency of water any more than a potentially higher water level during summer indicates surplus.

Most of California has a chaparral climate. Some of California has a desert climate. Such climates are naturally dry through summer. It is quite normal. It does not constitute a drought. A drought is an unusually dry weather pattern. It is not so normal.

Contrary to popular belief, California is NOT in perpetual drought. Although droughts occasionally happen, they are not annual events. Dry weather that occurs annually every summer is normal climate. If there is a deficiency of water here, it is because there are nearly forty million people relying on a limited supply of water.