Sanguinello, almost all citrus is grafted to Trifoliata or one of the hybrids here in the southeast & they all produce some of the best quality fruit you will ever find. Not many citrus have a compatibility issue with poncirus except certain lemons, which we graft to other rootstock.

You need to visit this area in the fall when the fruit is ripening.

I know it works, but the grafting shows the incompatibility.

Before Tristezza only citrus aurantium and rough lemon was used.

Now as HLB is marchin on, poncirus will be sorted out and citrus macrophylla and Volkamer will rise ...

The quality of fruits by both is even higher than Poncirus and also more profolic.
Besides the high vulnarity of Poncirus to wet soils and fungus (root and stem rot) and the troubles with basic soils ( PH ) will be solved.

Neither macrophylla or Volkamer are cold hardy. We will always use some type of poncirus. All of my in-ground trees are on trifoliata or swingle and have no compatibility issues. link

Well, what helps a cold hardy rootstock, if the scion is not ?

Besides, the Volkamer is hardy like a lemon and there are other hardy citrus like the 10 degree tangerine or Juanita ...

Nothing, if the scion is not hardy it is kept in a container & brought inside on the cold days ( here we only get about 5 days a year when the temps drop below 32f).

Trifoliata & it's hybrids have been proven to be a excellent rootstock for most citrus & will be used for many years to come. HLB is an issue, but sooner or later there will be a cure. I check my trees on a almost daily basis & have never found a psylid on any of me trees. I am also not in a citrus growing area and do not see a issue with HLB in my area any time soon. Not many people in my area realize you can grow citrus here & don't bother with it.

Sylvian the seedless Ichang is totally seedless. Sometimes there is just a trace of an aborted seed but I've never found a full intact seed in the fruits. The fruit is similar to yuzu in the amount of flesh and juice but just not quite as much. I think I may have a picture of the inside of the fruit which I will look for and try and post.

I should clarify what I meant to say about flying dragon. It is an excellent rootstock and is compatible with most everything and is even desired in cases where a smaller tree is a better fit for the situation.

My concern with it may be debatable. It is its dwarfing quality that makes it not my first choice of rootstock for an in ground tree here up here in my growing zone. In my experience the trouble with flying dragon is that its slower growth doesn't provide the graft enough growth to recover from a difficult winter. I've had a lot of grafts on flying dragon that die back just about to the graft union and come spring don't get growing with enough energy to recover and end up never making it. The very same varieties grafted on regular trifoliate, citrumelo or swingle sprout back with more vigor, are able to make it and gain enough size to battle through the next winter.

I know this sounds contrary to what others like as they prefer the flying dragon to keep the tree small in order to bank the tree or cover it during freezing spells. I prefer to high graft and do not protect my trees during the winter so far it has been what has proven to work.

The other observation is that after a heavy fruit set those branches and often the tree itself will be more prone to cold damage that winter. Unfortunately picking the all the fruit off before winter doesn't seem to help or make a difference.

> Sylvian the seedless Ichang is totally seedless.
So no chance to try new cross.
It could be a triploid.

>The other observation is that after a heavy fruit set those branches and often the tree itself will be more prone to cold damage.
Yes, it's very true. This year we had a very hard winter, between -15 and -17°C. Indeed nearly everything died. But on a multigrafted Poncirus only branches that bore fruits died. I mean the PT branch!

Hi G !

I think the plants would do much better WITHOUT any rootstock.
Maybe you give a try ...

About the dieing back :
One more trouble with Poncirus is that it has a MUCH longer dormancy than Citrus !

That means Citrus is more than a month away and urgently needs juice from the roots and Poncirus cannot deliver it, for not active ...
So damages at Citrus cannot be repaired and it dies back ...

Well, both scenarios can happen.

I still think on own roots the plants would do much better.

Yes if the plant will do well on it's own roots & you have years to wait for fruit, it is fine. The problem is many varieties do not do well on their own roots, or require such a high node count that they will never fruit if grown in a container.

There are good and bad in each scenario...

I mean that adult hardy ones G has ...

In Italy almost all farmers grow from cuts ...
Even many commercial nurseries do.

More, mostly citrus aurantium is used as rootstock, if a rootstock is used at all, and that citrus aurantium is propagated from cuts ...

I don´t want to tell which nurseries does what, for that is their secret, but nurseries you know do that ...

Just about zero "0" percent of commercial citrus trees the world over grow on their own roots, and never will. All commercial citrus trees, and almost every hobby and dooryard tree are grafted trees, not growing on their own roots. Even though citrus will grow on their own roots, and have for thousands of years, most all grow better, much better, on grafted root stock. Depending on the type of soil, the amount of rain, the diseases of the area, the pH of the land, salinity, drought, potential for freezes, nematodes, local blights and viruses, tree size desired and even the fruit size wanted, a citrus tree will grow and produce much better when the proper root stock is selected to fit the local growing conditions. Growing a tree on its own roots generally would not be a wise investment even for hobby growers, but NEVER for commercial growers. - Millet (236 BO-)

It is true that some varieties will make it on their own roots and survive in very cold zones. My Lemandarin, marmaladequat, changshas and thomasvilles are on their own roots but I do have some of them grafted on trifoliate as back ups. Other examples are some seedling grapefruits such as Croxton and mandarins like Juanita tangerine (although I haven't found this one as hardy as reported).

The problem with growing citrus on its own roots comes into play when you want to grow varieties that are very marginal for a cold zone and need that extra and deep dormancy to be able to survive harsh winters.

I would not be able to grow my beloved satsumas, nuclems, kerajis and calamondins if it were not for grafting them high onto poncirus. I have tried all these and some others on their own roots (as seedlings and rooted cuttings)and they die off after hard winters. In most cases if the tree isn't outright killed during the winter what happens is tree will suffer trunk bark splitting. Even though the tree overall may initially look fine in early spring, upon closer inspection the trunk and branches will reveal all sorts of splits and lesions that will lead to the eventual demise of the tree.

Sylvian it is an interesting phenomenon concerning heavy fruit set and less cold resistance. Sometimes on branches with heavy fruit set not only will the scion die back but to the graft union, but carries that 'death' back a few inches down onto the trifoliate or the whole trifoliate branch.