The Tropical Fruit Forum

From what I understand, Nippon orangequat is only as hardy as kumquat, which is only a little bit hardier than Satsuma mandarin.

They're edible, but some people complain that they are not as good eating quality inside as Satsuma (or a regular mandarin), and their outside peel is not as edible as a kumquat. That mixing together the traits of both are not really the most desirable thing for being able to enjoy the fruits.

From what I am noticing, going by the appearance of the leaves right now, the covering with the plastic bag and gallon container of water under there really helped protect the plant from the cold. The Bloomsweet that was covered looks better right now than the Yuzu that was left uncovered. Even though the Bloomsweet was only very haphazardly covered. The plastic bag only covered the top of the plant, although I pushed a little bit of snow up against the bottom to help provide a little bit of additional insulation. There were still plenty of big gaps between the bag and the ground. The temperature only went down to 18 °F. The leaves on the Yuzu look a little bit "fried" and pale, while the leaves on the Bloomsweet (which is supposed to be less hardy than Yuzu) do not look too bad.

Here are two pictures to give you some idea what the snow is like here.

Yuzu on grafted rootstock


Not citrus, but a (somewhat) rare Rhododendron yuefengensis


December 31, 2021

Here's the latest update from Christmas morning, December 24, 2021

Bloomsweet grapefruit


Keraji mandarin


Changsha mandarin (that's an Escallonia bush in the background)


Although you can see some snow and ice, temperatures had not really gotten that cold at the time of these pictures. Ambient air temperatures had not actually gone below the freezing point yet. The leaf coloration still looks pretty good in all three pictures. I'd say the leaves on the Changsha look the best, but it is somewhat protected by being half engulfed by that big bush.

However, temperatures tonight (December 26) are expected to go down to 18 °F, and the temperatures are not expected to rise above freezing for the next 4 days, which is an unusual thing for this climate. (It more often stays just right above the freezing point) Apparently there is Arctic air coming from the interior of Canada. It's actually colder here right now than in Minneapolis or Buffalo (although of course that will not last too long).
I put some paper grocery bags over both the Bloomsweet and Keraji with containers of water under there as well. They are not too far from the house. Right now there's about 6 inches of snow on the ground.

From research I've looked into in the past, there's probably a higher than 50 percent chance the seedling you grew was nucellar, so it may be an exact clone of the original parent hybrid. But there's also a fair chance, maybe somewhere between 20 to 40 percent, that the seedling could have been zygotic (probably resulting from hermaphroditic sexual reproduction. If that's the case there is a chance the genes might get scrambled around to improve characteristics of edibility and cold hardiness. But even those chances of an improvement are probably 1 out of 4, or 1 out of 8 (I would guess, from apply basic statistics to how dominant/recessive gene pairs work). I know this is very speculative but maybe that will give you some small idea of what could be happening here and the chances of any change from what you did here.

I do find it very interesting that you chose to use an actual pomelo in your (original) cross.

Only problem is finding an pure ichang papeda to be the female parent...

There's a very big bush-tree in the Hoyt Arboretum in Portland, OR, right up against the side of the visitor center.
I can tell you it grows very easily from cuttings.

For those in SC, Woodlanders sometimes has some, although they're prohibited from selling to you if you're in GA.

Keraji seems pretty promising too. Maybe you could try using Keraji to pollinate a zygotic selection of poncirus hybrid and hope for the best.
Loch Laurel sells Keraji but they do not do mail order.

I'm in zone 8a in the US, at a similar latitude to you (well maybe just a little bit less far north than Mühlacker).
I have multiple varieties that have been in the ground for 3 years and none of them have fruited yet. Well, only two (the Sudachi and Keraji) of them have seemed to begin to form just the tiniest beginnings of little fruits, but they never ripened in time and eventually fell off.
Of course something hardier like citrange might behave a little different. My Dunstan citrumelo has a reached a fairly medium size and still no appearance of fruits. But grapefruits are known to take much longer until they begin producing fruit.

Due to your more continental location, the summers where you are do just get a little bit warmer than where I am. About only 2 degrees F (just a little bit more than 1 degree C) but that can make a difference. Maybe your plants put on more growth during the growing season.

See, I'm growing in the Pacific Northwest region, and while hardy citrus may easily be able to survive through the level of cold there, they just have trouble putting on much growth through the year, due to short duration of the summers and the cool temperatures throughout most of the year, it seems to me.

You can also wrap a mesh cage around the plant in a circle and fill it with dead dry leaves. That should help provide some insulation against the cold.
For example chicken wire.

The rough lemon I found had a very pleasant fragrant smell to it, like a sour orange, but had too much bitterness inside to eat.

These two trees are growing in someone's backyard in Federal Way, Washington, right next to Decatur High School. (Federal Way is just south of Seattle)
The owners are a Vietnamese couple.

One tree is grapefruit and the other tree is a lemon. They are both pretty big, about 6 feet high.

They said they grew both from seed. They are not on rootstock.

I asked them whether it was a Meyer lemon or a special lemon. They said no, it was just a regular lemon like what you buy in a supermarket, not special. Their language skills were not the best though, maybe they did not know.

They kept it inside the garage for 12 years during each winter before planting it outside. The woman said the trees have only gone through one winter outside so far. Both trees have a frame over them, which they cover during the winter. But they do not use any Christmas string lights.

They also have several small fig trees in their backyard.

The first picture is the grapefruit, the second one is the lemon.



pictures taken October 23, 2021

The location is not too far away from the water of the Puget Sound, and it's in a built-up suburban neighborhood, which probably helps keep the temperatures from dropping too low.

I didn't mean that Sudachi really tasted like lime. I meant it is a little lime-like in the same way that Yuzu is a little lime-like, and that combined with the sourness if it is picked green.
Maybe it's more accurate to say it can be used much the same way like lime. There is definitely at least a little hint of lime flavor in there though, but also in addition to that there is something green and unripe that tastes reminiscent of a lime type of flavor.
Of course the flavor overall is much more like a zesty fragrant sour orange.

Picture taken October 7, 2021


The crushed up leaves smell very pleasantly spicily fragrant, more mild and less harsh than the smell of normal citrus leaves.
I mean I could almost imagine the leaves being used as a perfume ingredient.

Here's the latest update
October 3, 2021



sorry for the low resolution images, was trying to fit 4 images into one picture to help reduce data space

A - tiny keraji seedling
B - Ichang papeda
C - Sudachi
D - ichangquat seedling (regular seedling)

The coloration on the tiny keraji seedling looks green and a very healthy color. However, this seedling just overall does not seem to be putting on any growth. It was the exact same size this time last year. The winters seem to set it back and then it recovers, but it does not seem to be able to grow to a size bigger than it was before. Those little leaves are all new. (There are five leaves, two of them very tiny)

Most of the leaves on the Ichang papeda are still very light in coloration, yellowish-green. I would say more yellow than green though they are still obviously alive. It seems they were never able to green up much since the winter. If you look carefully, there are a small number of newer smaller leaves that are a little bit more green in color but even those leaves do not look a healthy green. There are two of these Ichang papeda plants right next to each other and the leaf coloration on both looks exactly the same. Perhaps this variety begins to put out its new leaf flush too early in the year, when it is still too cold, and so the newer leaves do not develop the most healthy greenish color. When the very small new leaves initially start growing, they are a dark reddish color. I have never observed this growing them inside. It probably is a natural response to growing outside, either to the ultraviolet light of the sun or the cold.

The color of the leaves on the Sudachi look just okay. Not really the healthiest deepest shade of green, but okay, still definitely green and not yellowish. This little plant has not been able to put on much growth. It is a slow grower.

I may be mistaken about this but the Ichangquat seedling has not been able to grow any new leaves. All of those little leaves you see on the seedling are all old, from 3 years ago, the leaves that did not fall off (most of them did). But amazingly those leaves look like a healthy deep green color. It seems obvious those leaves have been able to recover. I think this seedling has almost not been able to put on any new branch growth. Yet the recovery of the leaves and the fact they have fully recovered their color since turning very yellowish during the winter is a good sign.

(This is the normal Ichangquat seedling, not the other one that seems to be hardier that I suspect is a hybrid)

I would say that all four of these are managing to survive, but almost not putting on much growth. Very slow growing. It seems they are marginal growing in this 8a Pacific Northwest climate. None of them were protected or covered this winter.

Bear in mind these are not big plants.
I took some measurements. The tiny keraji seedling is only 2 inches (5 cm), the Ichang papeda is 14 inches high (35-36 cm), the Sudachi is just a little over 16 inches (41 cm) high, and the ichangquat is 13 inches (33 cm) high but very narrow, with only 3 leaves.


The bigger keraji plant (not shown in the 4 images in this post) has one small yellow fruit on it, which seems not to have been able to ripen in time. It is less than an inch in diameter. (I mean it is completely yellow in color, not the slightest hint of orange-yellow)
It is still a small plant, so maybe the fruits will be able to ripen in future years. It is 17 inches (a little over 43 cm) high right now.