Author Topic: Optimal rootstock for growing tender citrus in cold zones  (Read 3355 times)

Pancrazio

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Optimal rootstock for growing tender citrus in cold zones
« on: July 25, 2016, 07:11:16 PM »
I think that the question may be similar to the question:
"If you are going to plant a mango in a cold place, are you going to prefer a vigorous one or a dwarf one? One is quick to recover; the other is easier to protect."
Well, i'm in a similar train of thought with my citrus. I want (I really want) try to grow some citrus, especially pomelos.
But my place is a cold one.
As for now my best idea has been "I’m going to graft all of them on Flying dragon because they'll remain dwarf and i'll have a easier job covering them: also FD makes for awesome fruits and impart cold hardiness which is important".
But right now I’m unsure if this is optimal. I mean that for pot growing this seems cool, but once you think about putting them in ground (and probably being able to cover just the graft point on most years) probably the best bet is going to be a more vigorous rootstock to have a way to see them recover quickly from cold snaps and dieback.
So... what is a very vigorous rootstock that imparts comparable cold hardiness and flavor to scions when is compared to flying dragon?
I don't think that pest resistance in meaningful for me: i grow citrus outside from a citrus zone so unless i bring any post my place will remain pest free.
Also, is there any bitter orange x poncirus hybrid?
I was thinking about normal poncirus trifoliata or maybe some poncirus hybrid?
« Last Edit: July 25, 2016, 07:45:31 PM by Pancrazio »
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Tom

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Re: Optimal rootstock for growing tender citrus in cold zones
« Reply #1 on: July 25, 2016, 08:30:19 PM »
With most citrus grafts on Flying Dragon in ground it's been my experience that the tree will still grow too tall to pick all the fruit without a ladder. You can keep your trees smaller with pruning and you will still have lots and lots of fruit ! I don't want anything taller than maybe 8 feet which is still pretty easy to keep warm but you need adequate protection for long periods of below freezing temps. Everything else as root stock will be even taller than 8 feet tall and I think your fruit quality will suffer from what I've heard and observed so far. An expert that I respect a lot said a Meyer lemon in a half whiskey barrel (about a 25 gallon pot) could produce about 50 fruit if everything went well. My in ground Meyer had 350 fruit last year. It is not grafted but I keep it pruned to less than 8 feet each year. Hope this helps. Tom

Millet

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Re: Optimal rootstock for growing tender citrus in cold zones
« Reply #2 on: July 25, 2016, 09:53:24 PM »
Of the Trifoliate hybrids Carrizo Citrange is rated as good (G) for freezes, produces a large tree; Kuharske Citrange, rated G for freezes, produces a large tree; Benton Citrange rated G for freezes, produces a large tree; C-32 Citrange rated G for freezes, produces a large tree; C-35 Citrange rated questionable for freezes, produces  intermediate sized tree; Rusk Citrange rated poor to intermediate to freezes, produces a small tree; Trifoliate Orange rated intermediate to Good for freezes, produces a small tree; Sour Orange rated good for freezes, produces a intermediate to large tree.   

Sour Orange is rated good for salinity, high pH soils, clay soil, extra good for wet soils, intermediate for drought, good for freezes, high to high+ for juice.  It biggest weakness is that it is very susceptible to the Tristeza virus.   However, if your area does not have tristeza it is a great rootstock.
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Tom

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Re: Optimal rootstock for growing tender citrus in cold zones
« Reply #3 on: July 25, 2016, 10:35:27 PM »
Great information Millet ! What is size estimated for large ,intermediate and small ? What category is Flying Dragon as a root stock for in ground citrus ? Thanks. Tom

Pancrazio

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Re: Optimal rootstock for growing tender citrus in cold zones
« Reply #4 on: July 26, 2016, 01:32:28 PM »
Thank you for your suggestion. Given how easy it is to get a sour orange here, compared to the more "exotic" rootstock, i think i'll go with that.
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Millet

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Re: Optimal rootstock for growing tender citrus in cold zones
« Reply #5 on: July 28, 2016, 03:25:21 PM »
Tom how large citrus trees are depends on many things, such as culture, fertilization, wate,r climate etc.  However, dwarf trees in the ground can eventually grow to 15 feet, Large tree to 30+ feet, and medium trees to 20+ feet.  Commercial growers want to keep their trees under a height where  harvesting can be done using a 6 foot ladder. = Millet
« Last Edit: July 28, 2016, 10:37:08 PM by Millet »

countryboy1981

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Re: Optimal rootstock for growing tender citrus in cold zones
« Reply #6 on: July 28, 2016, 09:34:31 PM »
I was under the impression that trifoliate is more cold tolerant than carrizo.

Citradia

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Re: Optimal rootstock for growing tender citrus in cold zones
« Reply #7 on: July 29, 2016, 07:30:50 PM »
It is. My trifoliata trees went through the polar vortexes without protection without any problem , but all my other hybrids, including carrizo, died horrible deaths even with water barrels and coverings, packing in leaves, etc.