I finally finished my freeze protection system for 10 in ground trees. The micro sprayers are supplying 19 GPH. From the research I did before hand , this should be sufficient for normal freezes.
Karl
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Nice job Karl.

Do you hook up the pvc to a hosebib, and did you bury the white pvc?
Is the black hose for fertigation? Nice job!

Patrick
There is no PVC in the support. It is actually 3/8” cold roll steel bar that I welded together. I just painted it that Almond color since it was the best paint that I had in the shop. There are ¾” lines under ground and from this the small ¼” irrigation tubes connect to a three way selector valve. This way I can use the sprinklers or switch to freeze protection. If you look at the second picture ,you can see the small plastic selector valve with three hoses connected.
Karl

Very nice job. Let us know how it works out for you. From what I understand you need to melt all the ice off the tree before the sun hits it in the morning... ?

Great work Karl!

What's your average lows and your record low so far?

Good job Karpes. That is something I keep saying I am going to do and never get around to.

Here are some pics I took of a 90 tree grove not too from here, way outside of any normal citrus growing region. This guy really has it together, fertigation system and all. Of course he has a few bucks tied up in it too!

Ned, your friends 90 tree grove is on my MUST see list when I'm in SC on Nov. 16th. How many miles is the grove from your place? - Millet

Bob, I would guess it is around 70 miles.

Hi Ned isn't he up in Orangeburg somewhere ?

Adding liquid fertilizer to my system would be very easy to do, but I wonder what would be the advantages of doing this. Is it more economical or beneficial to use liquid fertilizer? I suspect that getting the product equally dispersed to my large and small trees would take some tinkering but would it be superior to granular fertilizer?
Joe, about every 10-15 years we get a real citrus tree killer freeze that dips the temps down into the low teens. The last one was in 1989 with lows at 9 degrees, so we are overdue for it. An unusual normal low would be in the low twenties
Thanks to all for the compliments.
Karl

We are in North California. Once in a while we get to 20 in the winter every 10 years. Our record so far is 12 deg F. Commonly our average winter lows are 24 deg F. I don't protect my pummelos, grapefruits and lemons. So far the last 7 years, I've only got minor damage due to the late season arctic blast. Of course I do tricks by grafting my grapefruits and pummelos lower in the canopy and the mandarins, yuzu or sudachi on the top.

Lazz, he is near Bamburg.

I believe there are several advantages for this individual in fertigation. He uses a lot of fertilizer, so the sales reprehensive is most likely more willing to work with him in developing a fertilizer program for his citrus. Other advantages that come to mind, is that he can shut off the fertilizer, or change the formulation, anytime he wants and the effects would show up much quicker than if he was using other types of fertilizer. I would think this would be advantageous where you want the trees to enter dormancy early.

The predicted low for last night was 23 degrees, so I used the micro sprayer system for the first time. Thankfully they missed the prediction and the low was 26 degrees. I don’t know why but no ice formed on the trunks of the trees. During this period of time I estimate that each tree received 210 gallons of water. Temps dropped to below freezing at 10 PM and rose above freezing at 8:30 this morning.
Karl

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Karl, the trunks not freezing is due to the temperature inside
the plant being warmer than freezing. Also, a better indicator
of how cold the temperature really is, is by knowing the soil
temperature. Most frost protection here is to protect the
fruit already on the tree so that the pulp does not freeze.
Freeze protection involves protecting the entire plant as
many times the ripening, maturing to some people, fruit
will not be saleable once the pulp has been frozen. Once
we know the fruit will freeze, we protect the rest of the
tree.

For several years growing Citrus, primarily fresh market
Oranges it was felt that if we got three good years out of
ten from a production standpoint we were doing okay.
It is the seven not so good years in which we can take a
real beating. One severe freeze affects the next two to
three years of crops is how we looked at the big picture.

Most people here when they run water in furrows late
night and early to mid morning want the heat from the
water to rise and protect the plant. Wind machines
force the warmer air to stay lower to the ground. In
the good old smudge pot days we tried to heat the whole
plant. Overhead watering these trees during a bona fide
freeze is not so bad for us. The water once it crystallizes
right on the tree helps insulate it. The thaw process may
not be so good for the existing fruit for fresh market sales
or for export but we have a tree left for next years crop
and in some years and in known cold locations this is not
such a bad deal. For the homeowner that is not interested
in selling their fruit they may want to look into overhead
watering as a means for freeze protection. Even frozen
pulp is still edible but not saleable for fresh market, that's
all. Essentially it is the aesthetics of the fruit and the quality
of the pulp that gets hurt but the fruit for most people eaten
soon will not be so much of a big deal. I've eaten some
Mandarins that had endured a freeze that I liked better than
the ones that had not been frozen that were shipped into the
grocery stores if that is any consolation.

I applaud what you are trying to do help your trees along
for the cold but 210 gallons per tree is too much water to
be left standing above ground unless it can seep into the
ground fast and infiltrate past the root zone even faster.
We apply no water directly onto the tree but keep the
spacings in between the trees moist, not wet. We are
applying 6 gallons per hour in a circular fan motion
that at best gets to about 2' at the closest to the base
of the tree. We are growing these in a Hanford clay
with a compaction layer about 3' deep and about 1 1/2
feet thick. Water will go through the hardpan layer
but it does so slowly which is why all we want are the
roots to be moist, not wet, as clay once wet will retain
moisture. Our micro-jet sprinklers placed in between
the trees are all one us uses for frost protection for the
Navels and the adjoining Tangelos.

Should you want to liquid fertilize then cut off the top
sprinkler and add a second sprinkler to your lower set
up. Look where the water has gone in the second photo
and you will see that most of the water had runoff to
one half of the tree. Ideally, we would like to have
about the same amount of water around all of the tree
if possible. I think you can correct that.

With some minor modifications I think your system
will work well for you. Thank you for showing us the
photos. You've done a great job here.

Jim