Chill hours, climate change, and my orchard’s winter so far

Temperatures are warming more in winter than other seasons, according to research carried out in the Central Valley, including here in Yolo County, by UC Agricultural and Natural Resources (UCANR). That is bad news for growers of deciduous nut and fruit trees.

Tree crops will move northward (a trend that is already noticeable). Breeders are working on new varieties of pistachios that have lower chilling requirements. In the shorter run, growers are working with “other tactics to improve winter chill, such as using overhead sprinklers to cool the trees and painting them white with liquid clay to reflect sunlight.

I have used both (in my San Diego County days) sprinkling during warm spells and painting of trunks and major branches to boost chances of production on varieties that are a bit marginal for my area.

IMG_2078
Orchard rows on Dec. 19, 2016. Trees in background just pruned. Those in front not yet, at the time. That’s the ultra-vigorous ‘Shaa Kar Pareh’ apricot in front.

Such tactics won’t be necessary for me this winter, however. We have had an exceptionally–by recent standards–chilly winter. At my location, December’s mean low and high temperatures were 36.8 and 54.9F, which is slightly below long-term averages for nearby stations (Davis and Vacaville). By comparison, our monthly means for December, 2015, were 39.4, 55.1; in December, 2014 they were 47.1, 58.0 (!).

This January, so far: 40.8, 52.2. The days have been cool, for sure! And that is much better than January, 2016: 43.9, 55.8; 2015: 39.0, 59.8 (!). Yes, 2014-2015 was pretty bad for the deciduous fruit trees.

My trees should like this winter a lot! Now, if only we can avoid really heavy rain in the bloom period. Given the trend so far this winter–on track for possibly the wettest ever recorded–that is certainly not something I can count on.

Beautiful, and not so beautiful, fruit. And the coming of rain.

Today is the last day of Sukkot, the day known as Hoshannah Rabah. This day might be my favorite holiday, even granting that it is not technically a holiday (in the no-work, Yom Tov sense). Beating one’s willow twigs against a hard surface is quite fun and satisfying, actually. It has deep mystical origins.

Moreover, our forecast calls for rain tomorrow. Sometimes the rain really arrives on time.

Hoshannah Rabah, in Jewish tradition, is the day the world is judged for rain. And tomorrow, Shmini Atzeret, is the day we insert the prayer for rain every morning (till Pesach/Passover in spring).

We had some rain the day before Sukkot began, but it was just a tease. Fortunately it’s been great weather all week for dwelling in the sukkah, though it’s been quite chilly in the mornings! But a shift towards a wet pattern in the coming first post-Sukkot week week appears quite certain now.

[Aside: If you are one of my liberal and/or rationalist oriented readers, the idea of a ritual and prayers about rain probably strike you as… weird. So, let me ask: Do you recognize that our collective acts can have impact on the climate? So do I! And so have the scribes and teachers of the Jewish religion. So much so that one of the central statements of this idea appears in the Torah, at Deuteronomy 11: 13-17, and has been part of daily Jewish prayer services for generation upon generation. it is also “inscribed on the doorposts” via our homes’ mezuzot. These passages about climate consequences are in the second person plural in the Hebrew for a reason. The link at the end of the first paragraph above concludes with a personal postscript by the author about how this day’s service at one time did not sit well with his rational instincts, but has become a favorite, as it has for me.]

Of course, Sukkot is a seven-day festival. I am doing this blog post from our sukkah, enjoying the light patterns and rustling from wind in the trees.

In addition to the willow and myrtle twigs and palm-frond spine that make up the lulav, the festival is closely associated with the etrog (citron). Jewish tradition demands the finest examples of this unusual but beautiful citrus for use during Sukkot.

I never knew that there was some chance that the Christmas fruitcake tradition had some connection to the etrog before reading a fascinating post on Hard Core Mesorah.

I do want to correct one thing in the post, however, which is based on a common misconception about fruit hybridization.

[The etrog is] a fruit that must be grown intentionally, with careful planning involved. It is not incidental at all. This is because the etrog is a pure species of citrus fruit. It is one of the only three pure species of citrus fruit, the fruits that are only indigenous to Asia; they are the Mandarin, the Pomelo and the Etrog (citron). All other species of citrus fruits from our navel oranges to our tangerines are just crosses of these species. Citrus fruit so easily cross pollinate that there are a myriad of varieties of citrus fruit. Those of you who have citrus trees in your backyard know this, if you have various kinds they often mix and your tree comes out covered with mutations of orange and lemons for example.

Mostly fine, except that last point. If you have backyard citrus, you may indeed have seen a tree that produces both whatever you expected (an orange, a mandarin, a grapefruit, etc.) and some ugly hard-skinned lemon-like fruit. But that is not because of cross-pollination from another nearby type of citrus. If this happens, it is probably because the variety was grafted on a rootstock of ‘rough lemon’ (which is very commonly used, especially in older plantings). If the rootstock sends up a sucker from below the graft union, any resulting limb will produce a fruit that lives up to the name, rough lemon. (Cut these suckers off before they get that mature!)

Cross-pollination does not change the nature of the current generation of fruit that a tree produces (unless we are talking about something like pollination-variant persimmons, but we are not). The hybrid that might result from cross-pollination can be seen only when the fruit of the tree that grows from the seed of the current tree appears.

So it is not correct that “Pollination from afar can take hold and mutate the fruit until it not at all distinguishable, and surely not fit for proper use as food or in ritual.” There are many reasons an etrog might be unfit for ritual use. It might grow too close to another fruit or branch and be deformed. It might get attacked by insects as it is developing. Most authorities would not permit an etrog from a grafted tree (which implies one indeed must take care to avoid cross-pollination with a different citrus if one is propagating trees for future generations of etrogim.)

OK, that is this year’s fruit and Jewish ritual post. (I used to do a lot of these; may I be inspired to do more in the new year.)

Chag sameach.

 

 

 

 

 

Last day

It is the last day of baseball season, and also the last day of the Jewish year, 5776.

Actually, it might not be the last day of baseball season–depending on what happens today. I am writing this just before all the “final” day’s games are about to begin. We could still have a tiebreaker game tomorrow in either league, and those count as regular season games. We could even have a game from the original 162-game regular season tomorrow–the Indians and Tigers will make up a rainout if either the Tigers remain in contention for a Wild Card slot or the Indians need the game to decide seeding in the Division Series. And, while the Mariners’ loss yesterday ended the dream of a four-way tie for the AL’s two Wild Card berths, a three-way tie is still possible. That scenario would mean the regular season make-up game tomorrow, followed by tiebreaker games Tuesday and Wednesday to eliminate one of the three. We’ve never had a three-way tie for a postseason berth. The Tigers (and their rivals) have to cooperate both today and tomorrow to get us there. Why not cling to the 2016 regular season just a little longer?

As for 5776, there is no question it is the last day, ready or not. We will get to mark the new year, Rosh HaShannah 5777, with first fruits from our land. The bowl shown here contains the first two pomegranates and jujubes of the season, picked today. The ‘Bartlett’ pear is also the first, though these need to ripen of the tree; I picked it several days ago, and it is just now about ready to enjoy.

29 Elul 5776 fruits//embedr.flickr.com/assets/client-code.js

The bowl also contains small bunches of each of the red grapes of our property. I believe they are, from left to right, Syrah, Barbera, and Zinfandel. They were planted by the previous owner, so I am going by the map of the vineyard, which is not the easiest to read. The grapes are not “first” fruits, as we have been harvesting them for several weeks and are near the end now.

The pomegranates are, at top, an Ambrosia. It has split, as pomegranates often do, and may not actually be ripe yet. The other is an unknown variety–we have three, planted by the previous owner, and for only Ambrosia did a tag survive–and should be ripe. Here are some more Ambrosia on the tree, which set heavily this year, while the second photo below shows the other one, with a few of its lighter set.

Ambrosia 2//embedr.flickr.com/assets/client-code.js

Pom 2Oct2016//embedr.flickr.com/assets/client-code.js

The jujubes (‘Jew Jew Be’) are the first ever to ripen here, on a tree planted two years ago. They are of the ‘GA866’ variety. Not the snappiest name, but a great-tasting variety that I also grew when we lived in the San Diego area. The tree has grown well; look closely at this photo and you might see the one remaining fruit. Yes, its first crop was just three fruits. One must start somewhere.

Jujube 2Oct2016//embedr.flickr.com/assets/client-code.js 

Shanah Tovah. May we have a sweet and fruitful 5777! And an exciting end of the (extended) regular season and postseason!

‘Spring’ already?

Normally, the first signs of fruit trees getting ready to bloom would be a time of excitement. But when several trees are showing such signs on the 26th of January, it is more a cause of concern.

It would be one thing if the trees are almonds. We just had Tu Bi-Shvat yesterday, after all, and this Jewish ‘New Year for the Trees’ is suppose to be at roughly the time that the almond trees begin blooming in the Land of Israel. And much of California, including this location, has a ‘mediterranean’ climate type, as has Israel. Yet this year we will have a second month of Adar, inserted because Tu Bi-Shvat has come “too early”; the almond trees are not supposed to be in bloom yet, and we need to adjust the calendar to keep Pesach (Passover) in its proper season–the full flowering of spring. I am told by a contact that almonds already are in bloom in Israel. Mine are merely showing the very early signs of readying to bloom. However, several other trees that should flower after the almonds are gearing up. And that is a worrisome sign of a spring coming too early. We still have winter rains to get through–expected to be heavy later this week, and probably in much of February–and the ever-present danger of wintertime frost and freeze, which can wreak havoc on blooms and young fruitlets.

This is the ‘Flavor Delight‘ aprium. Look at all those red buds. It will be blooming soon.
IMG_3749
‘Flavor Delight’

‘Flavor Delight’ tends to bloom early, but this is more than a week ahead of last year, when it was actually a warmer winter. This is a variety with an evidently low chilling requirement, so once the weather warms enough, it will bloom early. But this early? (I might have expected that in San Diego, but not this far north.) The first bud swell for this tree in 2015 was 3 February. Its current status is more than just early bud swell. Those are about to burst! A little over a week early may not seem like much, but I would have thought last year’s was early, and yet this year it is even earlier. I suppose we might have to get used to “early” blooming as the new normal, as the climate continues its general warming trend.

All three of my pluots are also showing signs of waking up. I have ‘Flavor King‘, ‘Splash‘ and ‘Flavor Finale‘ varieties. The first two of those began to show some bud swell around 15 February last year, but the whole tree was not showing swell till another week after that. The ‘Flavor Finale’ did not begin to show its very first bud swell last year till 22 February. So these trees are really early! One good thing is that maybe they will all bloom together. My cross-pollination was not good last year, because the ‘Flavor Finale’ did not really get going till the other two were nearly done.

IMG_3750
IMG_3753
Two pluots shown above. The first one is the ‘Flavor Finale’ and I believe the other one is the ‘Splash’

The pluots also did not have really full blooms last year, partly due to the youth of the trees, but probably mostly because the chill hours (or “chill portions“) in the area were quite low last year (which is an ongoing trend). This winter, December was quite chilly, but January so far has been rather warm. (Data summary below.)

As for the almonds, they have their buds swelling, too. Still, it is striking that they will not be substantially earlier to bloom than some of the fruit trees. Things are just a bit whacky this “spring” so far.

_____________
Our temperatures; look how cold December was in 2013 and how warm it was for the average overnight in 2014! Also how warm January daytime highs were in 2014. This month it has been cloudy most of the time (and raining!), so the the lows have been warmer at the same time as the highs have been cool. In the two prior years, January was essentially cloudless and dry.

Year Dec. mean low Dec. mean high Jan. mean low Jan. mean high Feb. mean low Feb. mean high
2013-14 31.7 59.1 35.9 66.8 44 63.2
2014-15 47.1 58 39 60 44.2 66.5
2015-16 39.5 55.1 43.7 55.1
January 2016 data through the 26th

The view

IMG_3378

The scene out back on the morning of Dec. 11, a little after 9:00 a.m. A good cover of frost around the vineyard, with our weather station and solar panels visible. Our property still mostly in the shade, but the goat dairy beyond in full morning daylight.

A week later, the sunset was not too shabby, either.

IMG_3379

Apples slowly recognizing winter is here

Even two and a half weeks since the beginning of a significant cold snap, the young apple trees look like they barely know it is fall.

IMG_0296

There is, however, more “fall” color now than there was just six days ago.

Untitled

The first apple tree (the rightmost tree in the first photo) is a red-fleshed variety. Its new foliar growth is also quite red, and the leaves retained a significant red tint well into summer. So it is not surprising that it also has the greatest fall color of any of these apples.

Even the Eucs have damage

The recent cold snap was more intense than expected. We dropped to 20 degrees (F) one morning for about an hour and a half, and over an eleven day period we accumulated about 95 hours below freezing and 14 hours of 25F or below.

Much to my surprise, even some mature Red Ironbark Eucalyptus has sustained damage. Not all the trees, but several. In fact, sometimes a damaged tree and a relatively unscathed one are side by side. Probably more a case of seedling variation than of micro-climates.

IMG_0293

IMG_0289

I am sure these will recover fully. What about my young citrus and other fruit trees? The jury is still out. The cold frames (and brooding lights) might have spared some of them, but we will wait for spring to be sure.