The forecast says the snow level will drop to as low as 2000 feet Saturday evening, locally 1000. We are at 1500.
It has been a really cold week, by local standards, especially for late February.
Too bad all this chill is basically useless for the deciduous fruit trees, coming this late. We surpassed 500 chill hours earlier this month. However, we really won’t get more useful chill, as almost everything is leafing out or blooming by now. And getting snow, or freezing temperatures on the buds and blooms is not a good thing.
Thursday, early in the morning, one of the most incredible storms this region has seen finally moved out. We had 6.25 inches in just over six days, 2.76 of which fell on Wednesday; many areas to the north had a good deal more.
It rained heavily enough for a time on Wednesday that we had a little river running through the property, not to be deterred by fresh prunings off one of the apple trees (which has several varieties that were grafted on to it last spring).
The main event of the rain lasted about 72.5 hours. During that time, only near the end were there as many as five straight half-hour increments (the archive time on my weather data-logger) in which no rain was recorded. At one time on 20-21 December, rain was recorded in 42 consecutive half-hour periods. That was part of a run of 123 of 132 half-hour periods in which rain was recorded. So, it rained rather persistently.
I can recall some phases of rain over a week or so long in the past that were impressive. As recently as January of 2010, for example. And no one who lived in Southern California at the time will forget “epic” rainy periods in 1983 and 1969. But usually these involve a series of discrete heavy storms, punctuated by several hours of some sunshine and no rain. This time, as the stats above reveal, it just kept raining. And raining. There were not even any breaks in the clouds, at least during daylight hours (and the record suggests not at night, either) from Saturday afternoon till Wednesday afternoon.
Today it was sunny and relatively warm (first time over 60 since 14 Dec.). But more rain is forecast for Saturday night and at some point during the coming week.
It’s a bit saturated around here.
We won’t have to irrigate for a while. And, thanks to that cold snap in late November, and more than a week of cool days (albeit fairly warm nights for the time of year) during the rain, we are almost to 250 chill hours already, which is good for the stone fruits.
On this Tu Bi-Shvat, there is much to celebrate as the fruit trees begin a new year. With the very hot January (or perhaps I should say most of Tevet and of Shvat’s first half) I had feared we would be too far behind in chilling accumulation for many of the deciduous fruit trees to bloom adequately.
It is still early spring (and today it feels rather wintry), but the signs are already very encouraging. The Mesch Mesch Amrah plumcot, which is always one of the harbingers of the bloom season, is now covered in blooms. A few blooms are now open on the Flavor Delight Aprium and Minnie Royal cheery. These all have quite low chilling requirements (300 or less?), especially the Minnie Royal, so their blooms are perhaps not especially indicative of significant chilling having been received. However, several moderate-chill (over 400 hours?) varieties are also showing bud swell, including the Autumn Royal apricot (usually a later bloomer), and the Moorpark apricot. Others that have chilling requirements most likely in the 300-400 range are also showing significant bud swell, including Newcastle, Katy, Royal Blenheim, Royal Rosa, and Shaa Kar Pareh (!) apricots and the Flavor King, Flavorosa, and Dapple Dandy pluots, as well as the Flavorella plumcot.
That concentrated chill in the second half of December/Kislev may have produced more chilling hours than I had dared to believe.
All in all, a good way for the trees (and their keeper) to start the new year!
As for Tu Bi-Shvat, with rain having washed out the trail, our shul’s annual ‘walking seder’ for the day was canceled, but the rabbi suggested we all hug a tree and eat dried fruits and nuts for the occasion. And my thought was, for that we need an occasion? Baruch ata Adonai, bo-rei p’ri ha-eitz! Now pardon me while I complete the blessing by enjoying some dried Royal Rosa or Shaa Kar Pareh from last season…
We are in the midst of a very unusual hot streak. For the seventh straight day here at Ladera Frutal, the high temperature passed 80 degrees (on the quaint Fahrenheit scale). This is quite a contrast with December, which featured seven straight days with a high below 60. I am not sure which 7-day streak would be rarer, but neither could be counted on to occur most winters. To have one such hot and one such “cold” streak in the same winter might just be unprecedented. (The December streak even featured a day when the high was only 49; that’s the only 24-hour period in the six-plus-year history of Ladera Frutal’s weather station to feature a high of less than 50!)
So the weather has been weird. And all this weirdness greatly confuses the fruit trees. There have been a few blooms sporadically on the Earlitreat peach since late December. This is not usually one of our first bloomers–it would usually start in mid-February after a few other peaches–but it always is the first ripener. One year it gave us fruit at the end of April. Maybe this year we’ll have peaches in March!
And I was out picking the sumptuous new crop of Page mandarins and suddenly my nose detected one of the most delightful of all fragrances. Could it be? Yes, there are a few blossoms on the Page! (Citrus usually start blooming after mid-March.)
There is still no sign of bud break on the usual first-bloomers: the Mesch Mesch Amrah plumcot, Newcstle apricot, Flavor Delight aprium, or Tropic Snow peach. (There have been blooms on the Anna apple, but that doesn’t count; that crazy no-chill apple always blooms in December.) But with such warm weather, I’ll be surprised if one of these is not beginning to bloom by the end of next week.
Of course a limiting factor in triggering blooms will be whether chilling requirements have been met. In fact, it is precisely to guard against too-early a bloom, with possible later freeze or frost damage, that deciduous fruit trees evolved their chilling requirements. If they have not had their chill needs met, they will hold off at least a little bit longer. But at some point, if the warmth continues, they’ll break dormancy anyway, but may not flower or fruit well.
Despite the warm spell, the chill count is pretty good, thanks to two factors: (1) that extraordinary cool week in December, and (2) the dry air. When the air is dry and there is no cloud cover, the nights can be chilly even when the days get quite hot. And it is with dry and cloudless nights that the full flowering, so to speak, of Ladera Frutal’s microclimates become apparent.
Up here at LF HQ, at one of the highest locations on the finca, the hottest day reached 89. That night it cooled to 56. Down the slope, at the coldest part, where all but the lowest-chill deciduous fruits are planted, the high was a bit lower, at 87. But the following night it got to 45. Yes, a 42-degree difference from high to low, and an 11-degree difference in low temperatures between the two locations! What a difference 100 or so feet of vertical change over 200 or so feet of horizontal can make! And in the protection of the big old grapefruit trees, the hedgerow (where I cheat on chill) stays cooler still: the hottest day was 83, rather than 87 or 89, and it is almost always 1-3 degrees colder at night. At times, even just shortly after sundown, we experience a 9- to 12-degree difference in temperature between the locations. Following Madison’s “scientific farming” principles, we have planted varieties in locations intended to maximize their microclimatic adaptation.
As a result of these microclimate effects and the dryness, the chill count is not too bad. Of course, it is not as good as the December cold seemed to promise, but it’s decent. By estimate it seems to have peaked around 310-320 at LF HQ, although we have been subtracting 15-22 hours a day during the hottest phase of the warm spell and now are probably under 250. By my understanding of chill models (and they are just models, not empirical descriptions) that means anything that needs 300 hours to bloom well would be OK, but anything requiring 400 would now need an additional 150, rather than 80-90 before it would be satisfied. Of course, anticipating that this part of the finca might often get under 300 chill hours, I have planted only low-chill varieties up here. (As well as tender subtropicals here and even higher, though that did not work out so well.)
Down in the corralito, at the lowest part of the finca, the chill count is much more impressive. We probably already had 265- 280 by the end of December, and with the impressive cold air drainage down the slope on these dry and cloudless nights, we have had very few significantly negative days. (In fact, at the coldest hedgerow location, none, unless you consider one night of an estimated -.25 chill hours to be “significantly negative.”) Thus down there the trees that are most exposed (to the air mixing of wind and to daytime sunlight) may have had no less than around 350 hours at their peak, while the more protected ones may have had as much as 375 even now (and counting!).
So as long as the heat wave breaks soon and we get even “normal” temperatures for a change, there remain grounds for optimism about the fruit season to come. The forecast calls for only moderate cooling for the next few days, but then a “pattern shift” by the middle of next week. If we are lucky, maybe the rains will return, too.
The fog was dense this morning, and is unlikely to break completely before sundown. Viewed from LF HQ, and looking out over our house below, one can just make out a little bit of our driveway and the grapefruit grove. Somewhere just to the right of the palm you can see the corralito. Oh, you can’t? Well, it helps when you know it’s there.
Down at corralito level, the fog is not quite as visible, but the deciduous fruit trees are being treated to a nice chill-containing blanket.
Thanks to the fog, the temperature stayed chilly. It did not even reach 45 till after 10:00 a.m., nor 50 till after noon. That meant many hours of chill accumulation, which should be great for the Shaa Kar Pareh apricot (foreground), and the cherries (back by the fence).
It has been a chilly winter so far, with more than 225 chilling hours accumulated at almost all levels of the finca, thanks in part to an unusually high number of days with lows in the 50s (and one that did not even get that high). And, while normally the chill is significantly less up the hill (due to cold air drainage down the steep slope) this year there is little difference, in part due to some near- or sub-freezing nights at the corralito. When the temperature is in the mid 30s and below, there’s little or no chill accumulation. (Prime temperatures for chill are about 38-45, and anything up to the mid 50s is still weakly positive.)
Late next week it may get rather warm. That will slow down the chill accumulation. But 225 hours is a good total as of the first of January, especially as some warm days at the start of December meant we did not really get started till well into the month. If we get another cold snap or two later in January or early February, 2009 might be another good year for the deciduous fruits.
Our Department of Fruitland Security has tried many things–with mixed success–to keep squirrels and other rodents, as well as birds, from getting the fruit before the humans can harvest and enjoy it. But a snake in the tree could be the most effective yet.
The problem with the snake-in-the-tree solution is, of course, that the snake doesn’t like to hang around in one spot. This one did, however–literally. It got itself caught in the bird netting draped over the cherry tree. To say the least, it was quite a shock for your orchardist as he went to harvest the cherries and was just about to sit down on the ground underneath the tree to untie the netting when he noticed the snake! (And I will admit that snakes give me the willies bad. I’ll put the photo on the inside branch in deference to others with the snake-willies. Click “more” at own risk!) (more…)
Another in the occasional series at the intersection of agronomy, astronomy, and spirituality…
Today, 21 March, is the first day of spring, with the vernal equinox* having arrived at 00:17 UTC (meaning technically spring began here yesterday afternoon). The following photo was taken at solar noon today from approximately the same point as the “Low noon” photo posted here on the winter solstice.
Because it is mostly cloudy today, unlike the sunny day we had on the winter solstice, the extent of shade cast over or near the hedgerow by the nearby grapefruit trees is not as obvious as I would have liked. Even so, you can see that it is only really dark on the south side (left of the photo) of the trunks of the trees in the hedgerow. With the sun angle at this latitude being 57.6 degrees today, compared to 33.9 degrees on the winter solstice, the greater part of these trees is already out of the shade and will be more so day by day as the trees grow (and, I hope, fruit).
Obviously, from the standpoint of the trees themselves, it has been spring here for a while. The tree in the foreground is the Geo Pride Pluot, days past its peak bloom. Several other trees are well on their way to leafing out and some are done blooming.
The upside of the freeze is that we had a lot of chill. Probably in the 650-700 hour range by the time a warm spell essentially ended chilling accumulation after the first week of March. And, as a result, some varieties that are marginal for the climate due to high chilling needs are blooming.
For instance, the Canadian White Blenheim. This has had some blooms in the past, but only sparingly and after being fully leafed out. I had never seen any stone fruit bloom after being fully leafed before, and the absence of any fruit from this tree’s few blooms in springs past confirmed my suspicion that such behavior indicates non-viable blossoms. As the photo above shows, this year it is blooming before the leaves, as one would expect if its chill requirement had been met. At the center of the photo are two open blooms from one set of buds, and several other buds about to burst. Unusual for an apricot, the flowers have a slight pink blush to them.
Even the Hunza is blooming!
As I have explained before, growing Hunza–and doing so right in the shadows of a large grapefruit tree–is very much an experiment in chill-cheating, and I had low expectations upon planting it. Blooms do not guarantee fruit, but they are a necessary condition, for sure!
Spring is here. And if the vernal equinox has arrived, then Pesach is right around the corner, at the full moon, as perfect for illuminating one’s liberation as the flowers of spring are for reminding us of the opportunities ahead. It is one thing to have freedom; it is another to make good use of it, whether we are talking about religious or political freedom. And, inspired by an orchard in bloom, this is as good a time as any for reflecting upon such gifts and their responsibilities.
On the Hebrew calendar, today is 2 Nisan.** The full moon will be (as always) 15 Nisan, the first day of Pesach. And for Christians (both Eastern and Western, this year***), Easter is the Sunday immediately following, 8 April.
* Unless, of course, you are in the southern hemisphere, in which case it’s the autumnal equinox, or the first day of fall.
** Meaning that 1 Nisan corresponded with the beginning of spring here–as presumably it should–given that the equinox was actually 20 March in North America, as noted above, and here the equinox was before sunset, meaning it was indeed still 1 Nisan.
*** If someone can explain the rules for calculating the date of Easter used by Orthodox Christians, please enlighten me. If Wikipedia can be trusted, Orthodox Easter will be 27 April in 2008. I believe Eastern Christians use the Julian calendar, but nonetheless, the equinox is the equinox, and this date would be more than a month after the start of spring.
In a comment earlier in the week, Doug Young noted that at his location in El Cajon (roughly 25 miles southeast of here) there were no freeze/frost problems. He mentions the location is about 1100 feet above sea level. That is much higher than here, where the Ladera Frutal office is about 525 feet elevation, as are the bananas that have been so badly ravaged by our freezing conditions. (Day by day, they continue to look worse than in the photo I posted on 14 January).
Doug notes how he can “feel the cold air draining downhill on a calm night.” I know what he means. That is usually the case here, too. On many a clear, windless winter evening, as I walk down the hill from the office to the house (elevation 450 or so), I can feel the air getting significantly colder as I descend. But not so on the recent evenings when the cold air mass settling overhead.
Compare 6 January, a more typical dry clear winter night, to 14 January, the coldest night of the recent snap. On 6 January, the low temperature down at the lower level (below the house, at maybe 350 feet) was 30 degrees, while up here at the office it got to only 36. Six degrees difference over an elevation change of 175 feet. Yet on 14 January, when the temperature reached 24 at the lower level, it was 27 at the office level. The cold air just was not draining. Instead, it was parked firmly overhead and the differences from elevation to elevation just were not very significant.
The steep slope here normally makes for a near-perfect mix of micro-climates–above-freezing at the top but very chilly down below. But it looks a lot less perfect than it did as of 12 January. This week, it would have been good to have been at 1000 feet (as the highest nearby ridgelines are). As an aside, I wonder how high, under local conditions, one can be and still get the advantage of cold-air drainage. At some point, the “thin air” effect of higher elevation has to take over, and one would be too high for cold-sensitive crops. One can see this effect on some of the hills east and south of here in Valley Center and San Marcos: Avocado groves begin part way up the slope and stop before the top, taking advantage of the parts of the slope that are out of usual freeze range. Of course, there was nothing “usual” about the weather this past week–and the impact on the local ag industry will be devastating.
Every day, more damage appears as the plants’ diminished ability to take in moisture leads to more and more collapse of tender young tissues and browning/yellowing and curling of foliage, even on some trees that appeared unaffected as of two days ago (such as the sapodillas, lychee, and some of the citrus).
On the upside, the cold snap has left the chill-hour estimate down below at 370+ hours, or about 100 hours ahead of where it was at this point a year ago.
This afternoon’s forecast update is an eye-opener:
BECAUSE FREEZING LEVEL IS EXPECTED TO VERY LOW…EVENTUALLY REACHING
THE SURFACE JUST ABOUT EVERYWHERE TONIGHT…ANY PRECIPITATION MAY BE
IN THE FORM OF SNOW GRAINS/FLURRIES
Photo taken around 10:00 a.m., 12 January
As promised, a cold storm has blown in. The recent forecasts suggest it will not bring much rain, and it won’t be as cold during the day today* as previously announced, but the nights could turn out to be even colder than expected as of a few days ago. Freeze warnings will be in effect. In fact, the forecast for San Diego valleys now says lows of 22 to 32 Saturday morning and 20 to 30 for early Sunday morning. I can’t recall when I last saw freezing temperatures at the upper end of the forecast range.
Very low (by local standards) temperatures are a mixed blessing for the fruit-grower. Temperatures below 33 are said by experts not to be useful for chill accumulation, but the cool days will still mean that the next several days result in significant net chilling. That is, a day with a low of 38 and high of 64 may actually be better for net chill than a day with a low of 25 and a high of 64, but something on the order of 25-55 should be really good for the deciduous trees. However, those lows could be harmful for the subtropicals, even if it is 7-8 degrees warmer during the coldest part of the night up the slope where most of them are.
When you are counting the chill hours that your deciduous fruit trees need, you don’t like days in January when the temperature is around 90. But yesterday was the first day of negative chill since 20 November, and we’ve had some remarkably chilly nights by Ladera Frutal standards. So, the chill count estimate sits at 276. Not bad for this early in the season.
And a good blast of cold air is on its way, beginning Thursday and then peaking Friday, according to this morning’s forecast (more…)
This the most frost I have seen in the corralito, where our highest-chill fruit trees grow, in five winters. (Well, that first winter, the corralito had not yet been built, nor any trees planted.) A lot of people who want to grow deciduous fruits assume you need to have frost. You don’t; in fact, the prime temperature range for the accumulation of needed chilling hours is about 38â€“45, Fahrenheit, and obviously frost occurs at lower temperatures. And when the air temperature is at freezing, the buds’ receptivity to accumulating chill probably freezes, too, until it starts to warm up. Still, when the morning starts off this cold–the photo was taken around 7:30 a.m., when it was 31 degrees–the chilly air is likely to stick around, especially if you can give the trees some shade and if you are in a canyon or valley that tends to trap the cold air. Only by about 10:00 a.m. did the temperature rise above 45, and the high in the winter-shaded part of the corralito (structured so as to “cheat” on the chill) barely reached 60.
Down at the bottom of the canyon, near the neighbor’s vineyard and by the horse track beyond, it was really frosted. This view is taken from the veranda of the house, about 75-100 feet above the elevation of the corralito and about 200 feet above the canyon floor. The canyon floor itself is about 240 feet above sea level, while those twin peaks across the canyon rise to about 1,040. The topography helps channel chilly air and keep it from draining away too fast on a windless morning.
Fortunately, however, there was almost no frost up at the higher parts of Ladera Frutal, where the bananas are planted, about 170 feet above the corralito (525 or so above sea level).
This photo was also taken shortly after 7:30 a.m., but unlike the shaded corralito, this part of the finca was already bathed in glorious early morning sunshine. The very steepness of these canyon walls and the varying sun angles are what give us the luxury of such microclimates.
Nonetheless, even farther up the slope than this location–up at 550 or so above sea level–the low was 33. That’s the smallest difference from top to bottom of the slope that I have seen on any morning when the lowest part dropped to freezing. Usually, when it is this cold, the same clear, dry, and windless conditions that give us the frost help keep the upper reaches of the finca anywhere from five to fourteen (yes, 14!) degrees warmer than the lower. Although there was no frost up there on the higher ground, those subtropicals that I planted back in October could be in danger from this cold snap.
After hardly getting any rain all winter, we’ve had a very wet spring, with a series of storms–a few quite big–passing through in March and the first half of April.
The wet spring followed a winter with quite good chilling accumulation (despite some warm spells along the way that made a doubter of me). The Mesch Mesch Amrah black “apricot” (actually a plumcot) is always one of the harbingers of spring. It had a good bloom, and the early signs of a good fruit set. But the wet weather did it in, and nearly all the fruitlets aborted by the end of March.
Most of the real apricots, on the other hand, have set better than I have ever seen before!
I am not sure now which apricot this is (shame on me, I know). It could be ‘Earli Autumn,’ ‘Autumn Glo,’ or ‘Blenheim.’ It does not matter,* because all of them (and also ‘Newcastle’) look like this. Look closely (especially on the large photo, which you can open in a new window by clicking the image) and you will see several very dense clusters of fruitlets!
The ‘Moorpark’ (as I have said before, my favorite) is still blooming. Fortunately, there have been some good sunny breaks between storms (inlcuding an 85-degree day on Friday), and it looks like it is setting.
Just today I noticed that the ‘Canadian White Blenheim’ had some blooms and several flower buds that are swelling. I have waited a long time to taste a true white-fleshed apricot. Could this be the year? (more…)
The possibility that apples might have been in that part of the world at that time in history did not seem right. However, it could be so. On the apple and its ancient cultivation beyond its probable origins well to the north of the Biblical lands, see the history at Vegparadise:
Some historians report the apple’s origins were rooted in Southwestern Asia, just south of the Caucasus Mountains between the Black Sea and the Caspian Sea. Others note that apple seeds found in Anatolia were carbon dated 6500 BCE. Archeologists even found a fossilized imprint of an apple seed from the Neolithic period in England.
And so maybe apples really are traditional to the Exodus experience after all, as the link Vasi provide above suggests. Vegparadise again:
In the 13th century BCE, Ramses II ordered cultivated varieties of apples planted in the Nile delta.
I would not have expected apples to have been grown in that region, given the climate. This offers more evidence that apples–even old varieties–do not have a significant chilling requirement! (The Nile delta would not get much winter chill, and while the climate certainly has shifted and the region was not always desert, it was also not temperate, but rather probably tropical around Ramses time. By the time of the Exodus, it had probably largely completed its transformation to desert.)
Even if apples were known to the ancient Egyptians and Israelites, there is still no way there would have been fresh apples to eat at the original Passover, assuming the first one really took place in springtime.
This discussion inevitably leads to the question of what Eve’s fruit of temptation might have been. I would guess pomegranate. The Vegparadise page agrees, but also suggests maybe quince. Quince seems unlikely, given its non-Middle East origins, but if apples could grow in the Nile delta, quince certainly could grow in the Tigirs delta, as they have quite low chilling requirements. However, quince are almost certainly also from much farther to the north, so presumably human traders would have been required to bring quince into the region. That somehow does not quite fit with the whole Genesis/Adam & Eve story, does it?
I often say the weather is weird here in Southern California, home to moderate temperatures somewhere between mild temperate and subtropical. But this winter–about to end, according to the calendar–has been weirder than most.
After not having a single day when the high temperature was below 60F through February 17, we have had seven since that date, including 51 on March 11. That was the lowest high I have seen in over a decade of daily temperature record-keeping in Carlsbad (by the sea, where highs below 60 are more common than here, but highs below about 56 much less so) and Ladera Frutal. The day at 51 (most of the daylight hours of which was spent between 45 and 47) was during that storm system that was promised to be cold, and it delivered. As I have lamented before, such weather would be great in January, but is somewhere between useless (for the deciduous trees’ chilling accumulation) and harmful (for already-open buds and for the subtropicals) when it comes in March, after warm weather in the previous months has gotten things growing again.
About the chilling. Even before the mid-March blast of cold air, we had certainly reached 600 hours in the open air of the lower reaches, and perhaps 650+ in the “cheat” zone. And the Moorpark (600 hours needed, say the catalogues) is gearing up to bloom!
This is a forecast I would love to see in January. But for March, after almost everything has had its chilling requirement met and, on account of some very warm spells many things are in bloom (see the two previous fruits.laderafrutal posts), this (from the 2:50 a.m. release of this morning’s NWS San Diego forecast discussion) could be quite bad news:
EXPECT VERY CHILLY DAYTIME TEMPS WITH PERIODS OF SHOWERSOVER THE ENTIRE AREA. SNOW COULD REACH SOME FOOTHILL AND INLAND VALLEY AREAS. THE TYPE OF WEATHER WE GENERALLY SEE WITH THIS PATTERN AT THE COAST IS CONVECTIVE SHOWERS THAT PRODUCE BRIEF…LOCALLY HEAVY DOWNPOURS OF RAIN AND SMALL HAIL OR ICE PELLETS. CURRENT INDICATIONS ARE THAT THE SHOWERY…COLD WEATHER COULD LINGER INTO TUESDAY. [Caps theirs, bold mine]
We’re not likely to be one of those inland valley/foothill areas with snow, but it could be cold. And hail is really bad news for fruit trees in flower.
If by my laws you walk, and my commands you keep, and observe them,
then I will give-forth your rains in their set-time,
so that the earth gives-forth its yield
and the trees of the field give-forth their fruit.
--Vayikra 26: 3-4