Back in the ice cream business!

The ‘Ice Cream’ (a.k.a. ‘Java Blue’) banana clump is very much back in business, after having been devastated by the freeze almost 11 months ago.

Look closely and you can see at least four sets of fruit and their blossoms. Each of these fruit-bearing stalks bloomed after the freeze, and while some of the bigger stalks lived through the freeze, there was no green foliage on this clump for a while after that setback.

A good long and warm summer sure has made a difference. And this is one of the very best bananas. If only we can avoid another cold spell, we are going to have a lot of fruit in the next month or two.

The photo below shows what this clump looked like on 16 January, the day after the first of five nights of freezing temperatures. (It looked a lot worse a week later.) The ‘Ice Cream’ is the clump to the left. On the right is the ‘Goldfinger,’ off which I just harvested the first post-freeze fruit Monday.

Just in from of the ‘Ice Cream’ clump in this photo is the ‘Bombay’ mango, which looks sort of OK here, but did not make it. Looking back at the first photo above, that empty circle of chicken wire in the shadows to the right of the banana clump is where the mango used to stand. Only a shoot off the rootstock (the aptly named ‘Turpentine’) now grows where the tree formerly stood. On the other hand, compare the avocado trees in the two photos. Now you would hardly know they ever had been harmed.

Lychee lives!

I had given up on this lychee tree long ago. I was just too lazy to remove it after its apparent death from the freeze of mid-January. Miraculously, six months later, the roots began to send up sprouts again!

Fortunately, this lychee was propagated as an air layer, meaning that it is growing on its own roots. If it were grafted, the new sprouts would be from a rootstock of some variety that was undesirable for its fruit and the desirable fruiting variety grafted to the rootstock would be a goner.

There is also a mango tree on the finca that was killed to the ground, but began to re-sprout earlier in July. However, it is a grafted tree, so the variety that is now sprouting is the all too aptly named ‘Turpentine.’ I might be able to graft a good variety on to it next year, however.

As for the lychee, the killed parts represented years of growth. So we still have a very big setback from the freeze. But the will to live is stronger than the freeze.

Avo graveyard

This is the view now looking west from Ladera Frutal HQ.

An avocado grove has been stumped and the trunks whitewashed. This is now a common sight in these parts, as trees that had their tops severely killed back in the freeze in January are being prepared for re-grafting on to the still-alive tissues of the trunks.* The whitewashing protects the trunks from sunburn; like many broadleafed evergreens, avocados have thin bark. Deciduous trees tend to have tough bark, because they spend a significant part of their lives without foliar canopy. Obviously, for an evergreen, a lack of canopy is an anomaly.

In the photo, at elevations just below the whitewashed trunks, one can see citrus trees (grapefruit, mostly) which have no damage from the freeze. (The entire canyon is now scented with their blooms!) And on the distant hilltops, the dark green represents avocado trees flourishing where they were planted high above the freeze line.

The following view is to the southeast, also from LF HQ, looking across the canyon. It shows quite starkly how freeze damage is a threshold phenomenon. There is no gradation in the visible damage as one goes up the slope. Rather, there is a line–the precise elevation of which differs with the contours of the hills and their sun exposure and air drainage. Below the line, devastation. Above it, healthy trees.

The damaged parts of this grove likewise have now been stumped and whitewashed.

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* Or, probably, simply letting them re-sprout, given that they probably have live tissues above the original Hass graft.

Cherimoyas, the spring after

Having been hit hard by the freeze in mid-January, the cherimoya trees are now budding again. This one shown here is the ‘Helmuts,’ probably the second hardest hit of our orchard’s block of cherimoyas.

The tops of the branches are killed back (i.e. the extremities suffered most from the cold), but the remainder of most branches is alive and now sprouting the growth of spring. Note the brown leaves clinging to some parts of the branches. Dead leaves cling to dead wood. Living tissue pushes its dead foliage off, and so now I realize that the massive leaf fall shortly after the freeze was a good sign. At the time, it sure did not seem that way!

Normally in this region, cherimoyas defoliate for a very brief period in April, thus making the cherimoya, at least in our climate, a rare case of a deciduous subtropical, albeit one that drops leaves only after the real deciduous trees have leafed out following their months of winter dormancy. These trees have now been mostly without leaves for over two months, and I had feared that they would be far off their normal cycle if they re-leafed too soon after the freeze. But now they are only a bit early, and I suspect they will get back to normal fairly soon, despite the shock. In fact, they might even bloom especially well this year, there being nothing like instilling the fear of death in a fruit tree to get it “thinking” about reproducing! Whether they can hold and ripen fruit their first year after such a big setback to their internal energy levels is another matter.

A lost gamble

This avocado grove is on the north-facing slope of Moosa Canyon in Bonsall.*

The mature trees on the ridge are really badly damaged. This hillside is right where two canyons converge, so it certainly would have been hit by a lot of cold air during the freeze in mid-January.

Below the mature trees some saplings had just been planted last summer. In the larger versions of this photo, the white stakes that supported these little trees remain visible. The saplings were probably killed.

This grower took quite a gamble in planting Hass avocados so close to the canyon floor. That’s Moosa Canyon Road visible at the bottom left of the photo (I am standing across the main road from where this grower’s access road heads up the hill.) Here the road is barely above the creek, so this is about as low as the canyon gets. I’d guess the temperature dipped close to 20 at creek level, and was probably below freezing even up where the mature trees are for close to eight hours one night and five or more the next. A gamble lost.
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* We are on the south-facing slope, and this grove is visible from here, a bit to the east.

Deaths in the orchard

This was how the ‘Thomson’ mango looked last May, as it was setting its first crop, and a heavy one at that. And were these mangoes ever delicious!

It will not look like this again. Ever. I can now confirm that this tree was killed by the freeze five weeks ago. Also killed was the lucuma that I had planted next to it last August, when the Thomson was laden with nearly ripe fruit. (I have not checked the other two mango trees, which grow on a more-distant ridge.) Here is what the Thomson and the lucuma look like now:

As can be seen to the right of the above photo, the mandarins are fine, and they are loaded with fruit. In fact, all the citrus seems fine, other than a few very young trees. The foliar damage is not trivial on some of the trees in the grapefruit grove down the slope, but the fruit appears to be of fine quality.

The two sapodilla trees (one of which was depicted just over a year ago, the day it blew over and had to be re-staked) are dead. The more distant tree in this photo has a distinct rust color at the base of the trunk–the color of death.

These trees, which produce a luscious fruit I have heard described as “pears with brown sugar,” had just set blossoms and, for the first time, were developing some fruit (from a previous bloom) that might have ripened this summer.

In the photo above, some of the freeze-dried blossoms can be seen. And in the branch in front, you can see where I scored the bark to see if it was green underneath. Nope. All brown, and so is the trunk.

A ‘Nabal’ avocado that was just finally looking healthy and mature enough that it might have borne this year is not dead (believe it or not!), but it is severely damaged.

(On the plus side, a ‘Stewart’ avocado just a short distance from the ‘Nabal’ is more or less unscathed.)

The cherimoyas probably all survived, but they look worse and worse with each passing week. They will take some time to recover. This year they had their first significant crops. Fortunately, about half the fruit had been harvested before the freeze. The remainder, some still hanging on these almost-bear trees, is now inedible.

I am taking a wait-and-see attitude about replanting mangoes, sapodillas, and other subtropicals that we have lost this winter. These trees are not cheap, even from 5-gallon pots, and when planted out that young, it takes three or more years before they reach bearing age–which these had finally done.

Banana re-growth

Much to my (pleasant) surprise, there is a good deal of new green growth from the banana stalks one month after the freeze. (Much more visible in the large format.)

Compare how they looked right after the freeze (when only the pups of the ‘Goldfinger’ appeared to have survived under the tent effect of the parents). (And then compare pre-freeze, as shown in the first-linked planting).

Protected pups

The mature, fruiting-age stalks of this ‘Goldfinger’ banana were damaged (perhaps killed) by the freeze. However, two ‘pups’ growing from the inside of the clump appear to have been spared, thanks to the protective tent created by the grown-ups.

Mamey dearest

Mamey after freeze.jpg

Originally uploaded by laderafrutal.

Two weeks after the freeze, it looks very doubtful that the Mamey sapote has survived.

It is hard to exaggerate how upsetting it would be to lose this tree. As depicted here previously, I grew this tree (and other tender subtropicals) in pots outside the Ladera Frutal office for a few years, in order to allow its roots to develop before planting, and so that the tree could be put into the garage when unusually cold weather was expected. Then in late summer, I planted the tree on higher ground, above the level at which frost and freezing temperatures normally occur. But the weather two weeks ago was anything but normal, and the tree’s survival is very much in doubt. We can go fifteen to twenty years without having a major episode of freezing weather. If only I had waited till this spring to plant…

Visible behind the mamey (and to the right of the stake) is the green sapote, which looks even less likely to have survived.

The canistel may have made it, albeit with significant damage.

The wild flower growing in front of the subptropicals, and heralding the arrival of spring-like weather, is obviously adapted to cold weather. (Oh, look at the canistel’s sprinkler! I didn’t notice that when I was up there. I’ll have to go fix that.)

The avocado grove after the freeze

Continuing the photo tour of the damage to Ladera Frutal resulting from the freeze of 2007. It has now been two weeks since the first of five nights of freezing temperatures. Over this time, damage that was not at first apparent has become quite evident.

Entering the avocado grove from its lowest part, the appearance is really grim. These trees may have survived, but they will be severely set back and may not fruit again for a few years.

However, enter the grove and things start to look a lot better.

These trees, just a few short steps from the ones in the first photo, are mostly OK. Only the very tops are “burnt” from the freeze. Obviously, the warmth of the trees themselves helped the trees protect one another. These trees will be OK by next year.

Still farther into the grove, and things look almost normal.

Up at the very top of our grove, you can look out over the entire grove. Only light damage is visible from here. Naturally, given the way cold air sinks, the upper part of the slope sustained less damage.

At the very top of this photo, however, you can see the neighbor’s grove. Although it is hard to tell from the photo, by the naked eye, even from this far away, it is clear that his trees were severely damaged. I always wondered why anyone would try to grow Hass avocados in the canyon bottom. He planted these trees only a few years ago, and he may have lost them now. (Click here for a view from a lower vantage point, which shows the grey disaster that is his grove.)

Almost all the avocado groves that I have passed by in recent days in the area have considerable damage. However, it is clearly worse on the canyon wall opposite ours–their north slope meant more hours of cold–and in some low-lying areas (like the neighbor’s) that are marginal for Hass avocados even in a normal year. This, of course, has been no normal year.

Many more photos, tagged “freezeof2007” at the Flickr set.

Cold air drainage & freeze/chill update

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.

Charred cherimoyas

Not only the bananas (as shown Sunday), but also the cherimoyas have been hit hard.

I have uploaded a series of photos tagged “freezeof2007.” We got as low as 27 here, and have not had a low temperature higher than 32 the last four nights. Make that five.

Blackened bananas

This is how the bananas look this morning, after two nights of freezing temperatures.

Click the image to open a larger photo in a new window.

Compare how they looked just over three weeks ago.

These mornings were the first in the four and a half years of my record-keeping that it froze this far up the slope. This morning the low up here was 27 (compare 23 downslope at the corralito). Even up higher where the subtropicals are, it reached 28, so the young trees up there (shown in the subtropicals domain planting immediately before this one) may not have survived.

Cold storm

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.

* Peaked around 55.