From what I've been able to figure out, Flying Dragon makes the ideal dwarfing rootstock for most citrus. But I also understand that the best rootstock to produce the highest quality fruit may be something else entirely.

So my question is, what is the best rootstock for Xie Shan with the following criteria in order of importance:
1. fruit quality (best ratio of sweetness to acidity, not size or quantity)
2. tree will spend entire life in container outdoors
3. for Southern California USDA zone 9b
a. hot (100+f), dry, summers
b. high Santa Ana winds

Planning to order some Xie Shan buds in June and need to figure out whether using FD will give me the best tasting fruit or if something else will. Again the priority is exceptional tasting fruit.

Thanks.

g00n, I talked with Tree Source Citrus Nursery about rootstocks last week, specifically for Xie Shan, as I'm going to order Xie Shan budwood as well. Both they as well as Clausen's are not so keen on FD, but instead Tree Source recommended Rich 16-6 trifoliate rootstock. So, that's what I went with, and will use this rootstock for all my budwoods. However, my trees are going into the ground, so that might make a difference.

Durling Nursery in Fallbrook stopped selling trees on FD altogether. They said it isn't a good choice for most of southern California. If I can remember correctly it's because of the hard water here.

They are budding simidwarf trees onto trifoliate and standard onto C-35.

From what I remember most trifoliata like a lower PH. Here in the SE all I use for rootstock is flying dragon, standard trifoliata or swingle. ALL of my Satsumas do very good and produce excellent quality fruit on these rootstocks.

I wonder about a decision to stop using Flying Dragon, and instead switching to Poncirus?????

On the other hand, commercial citrus nurseries mainly use root stock other than dwarfing types such as Flying Dragon, because their customers are commercial growers and their trees are for commercial production, in commercial groves, to be planted in the ground. Therefore, they want large full size commercial trees. The main reason for choosing a particular type of root stock is due to the type of soil and environmental conditions the tree will be growing in. All root stocks have benefits and draw backs, which one to use depends on what conditions that must be met for a given area.

gOOn's tree is to be grown in a container, not in the ground. Therefore a dwarfing root stock would offer a great benefit.

Using Flying Dragon as a root stock for a containerized Xie Shan tree, one could expect:

Juice quality = High (for sugar/acid rating)

Fruit quality = High

Fruit Size = A little smaller than fruit grown on a full size tree.

Yield/tree = Intermediate (an efficiency rating that reflects productivity for the size of the tree)

Tree size = Dwarf

Chance of Foot and Root Rot = Very Low

I have two Xie Shan trees, in CHC blends, which are currently growing in large sized air root pruning containers. Both trees are on Flying Dragon root stocks, and both trees produce a nice crop of excellent tasting fruit. Over the years I have found that container grown trees grafted on a dwarfing stock, such as Flying Dragon, do much better in containers than trees grafted on standard root stocks intended to produce full sized trees. As a root stock for container trees, Flying Dragon is by far my number one choice. - Millet (660-)

Flying Dragon is Poncirus, just the dwarfing variety.

Lazz, your correct, but the decision of switching from Poncirus to Poncirus, would yield pretty much the same results, except some what the height of a tree. The Flying Dragon variety is most dwarfing, but the other Poncirus varieties are also dwarfing, just less so. As far as I know, varieties of actual Poncirus, other than FD, are almost never used. - Millet (660-)

Yes, it makes you wonder what they are thinking. They don't want to use the dwarfing tri, they only want to use standard tri. I call BS...

Well, just to offer up my very elementary and less experienced opinion out here in S. California - commercial growers out here are trying to accomplish higher yielding trees that produce good-tasing fruits for eating in hand, on smaller, more compact and shorter trees. Full sized orchards with 20' tall trees are going by the wayside out here, in favor of trees less than 10', and planted closer together. Commercial growers then deal with less liability with workers falling from ladders and scaffolds, and requires less equipment and trees can be picked quicker, more easily and safely. So, from everything I have read, and from talking with some of the commercial growers in my area (N. San Diego county), those that can stay in business (water rates are putting many commercial growers out of business), they are opting to move to more compact trees that still can produce the same yields and quality fruits of the older standard versions. Probably telling you all stuff you already know Still on the learning curve myself. We'll see how my first grafting attempts go with my choice of rootstock.

Patty, if the growers want to accomplish what you have written above, then indeed they must use Flying Dragon (FD). FD is the only rootstock that will give them the dwarf tree that they desire. BTW, Dr. Malcolm Manners wrote some time back that a commercial grower will never break even if he plants an entire grove in a high density planting using FD. On the other hand others with good citrus integrity, claim that newly planted high density groves using FD can indeed turn a profit. As always time will tell. Whatever, for 10 foot trees FD must be used. - Millet (659-)

Wow didn't know my novice inquiry would stir such spirited debate.

@Patty - I saw your earlier post about the rootstock from Treesource in your budwood thread. The only difference between what we are both doing with Xie Shan is I plan to grow them in containers for their entire life (I believe yours were going into the ground), so I assumed a dwarfing rootstock would be more appropriate. That being said my primary criteria was fruit quality so was just trying to see if there was something better than FD or standard Poncirus. Do u have any data on Rich 16-6 trifoliate? Just trying to understand their recommendation. Thanks for your input!

@Chris - Yeah we have hard water here too, but didn't know that was a huge factor for rootstock. If it is a consideration in selecting rootstock, I'll try to keep that in mind. Thanks!

@Laaz - FD was my first choice for rootstock, but being the newbie, wanted to see if FD was just what the growers used because it was dwarfing at a minor cost in fruit quality. My priority is fruit quality, I can always get a bigger pot. Being that they will live in pots, I can easily adjust pH since I have plenty of pH down and up solution from all my hydro'ed plant experiments. Thanks for weighing in!

@Millet - Container soil will be Al's Gritty Mix. I've been using it on all my citrus and seems to work great but does seem to require more fertilizer when also following Al's fert schedule, than something in the ground.

All my previous research said that FD would not reduce fruit size, can you comment further on this? That would put a mark in the "cons" column since fruit quality is my highest priority. Thanks for chiming in!

----
All, to further muddy the waters, how would Cuban Shaddock compare to Flying Dragon or Rich 16-6 for Xie Shan based on my original criteria? Nearly all of the Four Winds trees I have are on Cuban Shaddock.

Ah, yes. The heated debate about rootstock selection rages on It's funny, when I first started to try to become more educated about citrus growing and production, I would ask around about rootstock selections with various growers, and got some guarded information, or mostly not much information. I did find out that nearly all local citrus growers in my area have stopped using Flying Dragon, as production is affected here in our S. California soils.

I ordered the "California Citrus Rootstocks" book produced by UCR Extension, publication #21477, which gives a nice history of the progression of rootstocks used in the state of California. The first the move were from roostocks that were susceptible to tristeza, which prompted the move from sweet and sour orange rootstock to the development of Troyer and Carrizo sweet orange x trifoliates in the 1940's. Not only did commercial growers benefit from tristeza resistance, but they also enjoyed some increased tolerance to cold. Plus, the smaller flowered trifoliate rootstock crosses imparted larger fruit, were more efficient (produce more fruit per unit of canopy volume), and matured their fruit ealier than the larger-flowered cultivars. In high-density plantings, small-flowered varieties can yeild earlier returns. If a commercial grower can supply fruit in a timeframe where that fruit is not normallly available, the grower can comand some higher prices for that crop. These attributes fit nicely with increased citrus plantings in the colder San Joaquin Valley that was beginning to happen (1950-1970's). This was the beginning of the commercial citrus shifting from predominantly being grown in S. California, to moving to Central and N. California, as water prices spiraled out of control for S. California commercial growers. This migration to the north continued to spike interest in cold-tolerant rootstocks. Trifoliate orange (Poncirus trifoliata [L.] Raf.) is now commonly used in the colder area of the San Joaquin valley where their soil pH permits, as well as Citrus marophylla (Alemow) introduced as a lemon roostock for S. Calif. coastal Eureka lemons (Eureka lemons have some unique scion-rootstock incompatibilities plus have needed rootstock more tolerate of salty soil conditions due to being better suited for the coastal California areas). These 4 still dominate the rootstocks of commercial growers in California.

Recently, there have been some newer trifoliate cross rootstocks developed, mainly C-32 and C-35, with the focus on other types of disease resistance. Both are citranges, hybrids of "Ruby' orange (Citrus sinesis [L.] Osbeck) and trifoliate orange. C-35 is generally more tolerant of phytophthora than C-32 or Troyer. Although Swingle is not highlighted, it also is a fairly popular rootstock for us here in S. California, as well as Rubidoux and it's newer version, Rich 16-6. And, the focus on compatible rootstocks in California have mainly been focused on rootstocks for Valencia and Navel oranges, as well as Eureka lemons, since those varieties make up about 70 percent of the total commercial citrus production in the state of California, with mandarins, grapefruit, other lemons, limes, tangelos, tangors making up the remaining 30 percent. And optimal California rootstocks for those varieties are still kind of a question mark. There are known scion-rootstock incompatibilities with Eureka lemons (trifoliate crosses) and Satsuma mandarins (Troyer). And, some recent concern with mature Navel orange tree decline on trifoliate rootstock as well. Rootstock trialing is being conducted for Satsumas and red grapefruits here in California to identify optimal compatibilities.

So, probably way more info than you were wanting, lol! This is a summation of what I know. It will fill a thimble of what other experts such as Dr. Manners and others on our list know, but for my specific area, and in talking with Citrus Tree Source Nursery, who provide large amounts of rootstock seeds and seedlings to our commercial growers, for my purposes, either Rubidoux, Rich 16-6 or C-35 are probably the best choices in general. Here is a nice general article about rootstocks for Orange County: http://www.lagunahillsnursery.com/gary-citrus.htm . Also, another good article from the University of Florida about rootstocks: http://edis.ifas.ufl.edu/hs221 . In this article, it does discuss that the trifoliate rootstocks DO provide some dwarfing qualities that have become very popular in California. Not super dwarfing, like FD, but 15 to 20%, which can make a difference for a commercial grower. HTH!

gOOn, I have perhaps a dozen trees growing on Cuban Shaddock (CS), as both in ground and container trees. I also have perhaps 20-30 trees growing on Flying Dragon (FD), these are also both in ground and container trees. As you wrote above, Four Winds Growers uses Cuban Shaddock as their root stock, and calls their trees "True Dwarf". I like Four Winds trees, and I like Cuban Shaddock root stock, but at least here in my collection, CS is not as dwarfing as is FD. That is not to say that CS is not a good root stock, it is just not the True Dwarf.

gOOn, I notice above your wrote ----"wanted to see if FD was just what the growers used because it was dwarfing at a minor cost in fruit quality-----. Where did you get that information? FD fruit quality is rated as high, by most all authorities. Your previous research where you found that FD would not reduce fruit size, I have also heard that, and on more than one occasion, however the University of Florida list FD fruit as small to intermediate. As I mentioned before I have a lot of trees on FD. I would say that the fruit size is just a little smaller than say fruit growing on Smooth Flat, Sweet Orange, or Carrizo.

Sorry I can help you out on Rich 16-6, as I have never grown a tree on that root stock. Whatever you decide to use as the under stock for your Xie Shans I wish you the very best of luck with your efforts. BTW just as a side note, unrelated to your request, I have several trees grafted upon Yuzu. They have turned out to be very good trees. - Millet (658-)

Must be nice to have all those choices on Rootstock for Xie Shan. In Florida I can only find it on Kuharske. Millet I would appreciate any thoughts you might have as to what I can expect in regards to fruit quality and size, fruit bearing, mature trees size and growth habit....etc

Darkman Kuharske is not all that bad of a root stock. Kuharske reacts well against freezes and drought conditions. Also has resistance against most common citrus viruses, and should produce large sized fruit of intermediate up to good quality fruit as the tree ages. Kuharske is a vigorous root stock and can produce larger trees. You should have some nice trees. Remember, no matter what root stock is used, a tree generally does not produce it best tasting fruit until it is approximately 5 years of age. However, Xie Shan frequently produces fairly good tasting fruit in year 1 or 2. If you are going to the 2011 Citrus Expo in Florida next November, it would be a pleasure to meet you. - Millet (658-)