What rootstock is usually used for container-grown citrus?

[Daintree]

Most/all of my citrus appear to be grafted.  I have bought them from local garden stores, and some from a place in Oregon. Mark in Texas recently found out that my finger lime is grafted onto flying dragon.  This made me wonder what the others are grafted onto.  Is there a "standard" or "usual" rootstock that is used? Just curious...

Carolyn

[Isaac-1]

Here in Louisiana we have two main citrus nurseries, until recently my understanding is both used Carrizo as their primary root stock, one of which also sells some dwarf versions on flying dragon.  I have recently learned that one of these nurseries (Saxon Becnel) is now primarily using Kuharski Citrange, which appears to be a Carrizo variant, except on Limes and Kumquats which they grow on C-22, which I believe are incompatible with Carrizo.  There seems to be little information online about Kaharski, and most of it is dated in the last few years.  In my research on this root stock , I noted that about 1/3 of Florida citrus was being grown on this root stock a couple of years ago.

[Daintree]

Interesting!
Thank you!

Carolyn

[Millet]

Most all of my container grown citrus trees are grafted on Flying Dragon.  It is so, because I request that Flying Dragon be used as the root stock.  My in ground Cara Cara which is now fully grown (11-ft H X 11-ft W) is also growing on Flying Dragon.   It is no doubt a great root stock for container trees.

[citrange]

I have spoken to several nursery growers (mainly European) about this.
It appears that they have two approaches to rootstocks.
Firstly they use whatever they have found quickly produces a visually appealing tree; secondly they use whatever is being used locally for in-ground commercial citrus production.
There is little scientific research into rootstocks for long-term container growth because there is no commercial driver for such research. Further, the container growing mix and growing environment is likely to be much more variable than for a commercial fruit grower, so comparisons are difficult.
The producers aim is to have a good-looking plant ready for sale in the shortest possible time. Fruit quality or plant growth after the first few years is of no interest to them. In fact some producers have admitted to me that it does them little harm if a plant dies or gets thrown out after a couple of seasons. They then have an opportunity for another sale.
The number of buyers who - unlike members of this forum - have any knowledge of rootstocks must be very small.

[adriano2]

I got my balcony citrus grafted on to poncirus. Not very happy about it though. Every year all leaves drop down.

[Millet]

adriano, nice seeing you on the forum again.   Discouraging when container tree lose their leaves (commonalty known as WLD).  However, I doubt that the cause is the poncirus rootstock  I have many container citrus growing on poncirus rootstocks (Flying Dragon), and they all keep their leaves all winter long.

[adriano2]

I am doing something wrong, but i do not know what. I closed the balcony with so called finnish glass, planted them in huge terakota containers, water them only with stayed or boiled water, only organic fertilizer.  last year i was happy to see them surviving winter untouched, only to see them losing all the leaves in spring and summer.

[Millet]

Organic fertilizers are fine for outside in the garden, but do not work well in containers.  In order for organic fertilizers to release there nutrients, they have to be first broken down by the soil microbes to become available to the tree.  Garden soils are teaming with all sorts of microbes, but not so in container mediums.  Also, if the foliage of your container plants is receiving direct sunlight, then be sure that the container itself is also receiving the same sunlight light.  Do you have a soil thermometer?  What is the temperature of the container's medium?

[adriano2]

I do not have soil thermometer , but soil temperature is lower. I have thermocamera on mobile phone and temp. difference is visible. Foliage do receive direct sunlight,  containers not because of the fence.

[Millet]

adriano,  what you wrote above about the sunlight and temperatures of your container citrus is a problem   The link shown below which was posted earlier on another post by Isaac-1 should be a big help to your problem.
http://www.crec.ifas.ufl.edu/extension/trade_journals/2011/2011_Nov_root_temp.pdf

[adriano2]

Thanks for the link

[snek]

Adriano : For citrus grown in containers in a cool climate is Poncirus Trifoliata the best choice. There is certainly no problem in Poncirus as such but in something else.

Millet : "Organic fertilizers are fine for outside in the garden, but do not work well in containers"
I'm not so sure of that. Do I use predominantly organic fertilizers and ...? Look at my citruses. But at the same time I say that in the spring a large part of the roots will be poured into the ground.

[raggashack]

i know you are all growing citrus way longer than me, but for me i think the problem is constant overwatering my citruses. I now think that the size of the container is the most important factor, way more important than fertilizer or a good medium. I have 5 plants, and the 3 with the "highest" containers are losing the most leaves, 2 of them are naked, the other one got a few leaves left.
I really mean the height of the container, not the size, even though the size should be almost the same as the size of the rootstock.
whenever i planted a citrus in a way to big container it died ._.

I also think all this only applies when the soil temperature is less than 27°C (80°F) , what it definetely is in winter in my zone (19,5°C = 67,1°F for my pots).

but i could also be very wrong, iam not sure at all

[Ilya11]

My be the solution is in  less water retention due to a better drainage, not just in the height of container.

[adriano2]

Snek: after i read the link Millet sent, i think problem could be cool roots which brings drought as result. However, healthy green leaves fall down. it does not look like drought simptom. 
raggashack: maybe there is something to it. My orange in smallest container (still 70 liter size) loses less leaves than other 2 citrus in bigger containers.

[Millet]

When leaves are discarded form a citrus tree, due to WLD (Winter Leaf Drop), they are normally healthy green good looking leaves.

[adriano2]

Could watering with warm water help?

[Millet]

Adrino, water with temperatures between  70 to 90F (21 to 30C)

[SoCal2warm]

I believe that being in a container has a natural dwarfing effect on the tree, constraining the root growth, so I believe it may not matter too much how dwarfing the rootstock is.

[loneroc1]

Howdy all,

I grow my citrus trees in a US zone 3 greenhouse. Some are in pots. Some are planted directly in the ground. All are on Flying Dragon. I set the low temp for 40°F (4°C). I'd set it lower but my thermostat doesn't allow this. The greenhouse air temps stay in the low forties on cloudy days. I try to keep the air temps below 70°F on sunny days. The soil temps generally stay around 40 for several months in mid winter.

I have never had any issues with leaf drop. None. My fall fruiting mandarins and my Meyer's lemon ripen fine. My only winter ripening trees are too young to fruit, so I can't say whether the low temps would affect their ripening days or fruit quality.

Thanks, Steve H (loneroc1)

[Millet]

Lonerlc1, your trees have no leaf drop because you are keeping your trees in balance.  Low root zone temperature and low, leaf temperature equals no, or little leaf drop.  Higher root zone temperature plus higher leaf temperature equals no, or little leaf drop.  Low root zone temperature and HIGH leaf temperature equals big time leaf drop.  Balance is the key.

[Solko]

Thank you for clarifying that, Millet, that explains a lot of what is happening in my greenhouse this winter...