weird kumquat leaf drop issue

[incubator01]

So I bought 2 kumquats from oscar tintori a few months ago, one with a short thick rootstock  and one with a half-stock (alemow) rootstock.
At first they were fine but not long after (say about 2 wees later or so) the first one started dropping a leaf a day, sometimes 2 or 3.
When the second arrived, same thing happened.

Now after 3 months, the first one is almost bald, it has many new growth, new stem and leaf shoots (above the graft) but even the leaves and once a whole new tiny branch fell off.

In the beginning when they just lost a few leaves it seemed obvious it was due to the wind, our climate was also colder than it should be, so I moved them into the greenhouse.
Since they're nagami kumuats they should handle 38+ °C (this season it hasn't even gotten that hot yet inside there).
To aerate the greenhouse I do open the windows but when there's heavy wind they're only a bit open, when there's less wind but sun I open them medium and when there's a lot of sun but low/no wind I open them fully.

Weather surprised us sometimes so again I thought some of the new growth could have blown off from wind gusts, but it's getting calmer, less wind and I see the new kumquat dropping more leaves, even fruits and new growth too just like the first one. The first one who is almost bald seems to have stopped dropping stuff.

Since I do not see any visible pests right now and I did spray them a few times before when I saw pests on other citrus I exclude this from the list of possibilities.
There's no sign of leaf miner.
The first kumquat has perfectly dark green healthy leaves (which he dropped) and the second one has that too but a part of them are curled down (seems they grown this way because they're very hard) and have yellow edges, as if they watered it too much (it was like this on arrival) or nutrient deficiency.
I'm giving a fixed proper watering schedule and feeding them properly too (except that I gave them some CaMg a few times before I knew that was not good for citrus).

In any case the strange thing is that only those 2 kumquats are affected, other citrus nearby (shikuwasa, mediteranean sweet lime, kaffir lime) are unaffected. while they stand right next to them.

And yes, container size is too big, I know, but there is no sign of root rot. I feel deep in the ground before I water and it never felt moist when I had to nor did it smell like fungus.

The first kumquat (that is almost bald) did have pests in the beginning though because I found orange resin on a branch that was pruned by the seller, I was able to scrape it off because this stuff attracts ants. Afterwards I applied a mixture of neem oil with brown soap once a week for 2 times and I always did the other one too.

[incubator01]

Attached are some images of both plants.

The first three are from the one I have since march and is almost bald:







the next two are from the other one I have since beginning of april and is starting to loose stuff:

[brian]

I have a ton of container kumquats and they take forever to start growing in the spring, almost to summer time before they start putting new growth.  Mine lose some leaves every winter and just now starting to put new buds out.

The leaves in your photos (except the last one) look a bit yellow, I would apply more fertilizer and maybe a foliar spray to green them up quickly. 

I wouldn't worry too much if the roots are okay and the twigs are green.  If the twigs are green they WILL GROW

[incubator01]

yeah those yellowish leaves had it when the plant arrived, I already feed it as much as I'm allowed so that's fine but I think they've been yellowish for a long time already. and thus will remain this way.

What I just don't understand is why young tiny leaves that just grew would fall off, not just from wind but by just touching the plant gently.
I'm considering leaving them in the greenhouse for not losing anything more because moving them around is bound to make them drop more.

[brian]

I can't say much about that... young growth is extremely fragile, sometimes it comes off when I spray with a host blast to remove scale insects.   If it is not discoloring, shrivelling, or otherwise looking sick and is simply getting knocked off easily then yes protecting it from wind is a good idea.  If it *is* turning yellow or black before falling off then it isn't a mechanical issue but something else.

[incubator01]

I can't say much about that... young growth is extremely fragile, sometimes it comes off when I spray with a host blast to remove scale insects.   If it is not discoloring, shrivelling, or otherwise looking sick and is simply getting knocked off easily then yes protecting it from wind is a good idea.  If it *is* turning yellow or black before falling off then it isn't a mechanical issue but something else.

yeah, that's what I thought too, it was in perfect green healthy color when it fell off, even smelling lovely like citrus from the juice coming out of the leaf where it broke off
But it does seem to be an extremely sensitive plant to wind or temperature changes, that's for sure.

[brian]

Overall kumquats are really fantastic container plants.  I think your plant will stabilize and be very productive if you keep it happy.  The nagami types especially look really nice.  I intend to keep mine about this size permanently.

[Millet]

Looking at the first picture, is the potting soil that the tree is planted in manly just a peat moss & perlite (regular commercial retail potting soil) ?

[incubator01]

Looking at the first picture, is the potting soil that the tree is planted in manly just a peat moss & perlite (regular commercial retail potting soil) ?

The soil is a mixture of perlite, Mycorrhiza and Mediterranean commercial retail soil. I grew tired of losing dozens of plants with all those weird soil mixes with components I could not find.
The soil contains white peat , clay and lava. (according to the description)
I lost plants to the 5-1-1 soil (pinebark, perlite and something else), also with equal arts of perlite, vermiculite and peat moss, specific commercial citrus soil and regular soil.

If the soil is the problem, then all my citrus would be in bad shape, yet those kumquats  right now are the only ones with issues.
I have the following plants in good condition:
- keraji
- 3 shikuwasa
- mediteranean sweet lime
- pursha lime
- 3 kaffir limes

[Millet]

Incubator01,  you wrote you lost trees in a 5-1-1 medium (5 parts pine bark chips, 1 part perlite and 1 par peat moss), sorry that happened.  However, many thousands of people have outstanding success, enclouding myself, with 5-1-1.  Whatever, from your picture the medium you are using looks to be on that does not provide the amount of aeriation required by citrus.

[incubator01]

Since 2 kaffir limes also have leaf drop recently I was thinking, even though they've ben outside under a patio for several weeks before, and then put against  a south facing wall to get the morning sun, they did get some noon sun, unfortunately that part was pretty hot,, I noticed that some leaves burned soon after they fell or some when still on the plant. The outside announced temperature was 28°C but in the sun it was much warmer, so I think some got burned. no branches were damaged, but definitely leaves and stressed out for sure.

Due to announced thunderstorms I placed everything back under the patio and leaf drop has reduced on the kaffir limes but the kumquat still drops a lot.
The other one that is almost bald I planted in my greenhouse, in full soil, where there's a shade cloth to filter 50% of the sun. It seems to be enjoying it since nothing dropped yet.

[incubator01]

and maybe off topic for this question but possibly partially responsible for what caused this:

When I bought these plants, the first kumquat that is now almost bald, was left in its original container untouched for over a month due to bad weather, it was too cold to and early to transplant anything.
The others I let rest a few days after they arrived before transplanting them.
Perhaps the mistake I made was when planting them in their new container was adding slow release fertilizer right away, even though it never touched the roots, some places say to wait a few weeks before doing that.
One thing that was off though was that the leaves on the second kumquat already looked yellowish, and so did the leaf stems, as if there was a nutrition deficiency.

But they could also have been "pampered" too much in protected areas like greenhouses and then the moment they're put outside they start to freak out...
It always happened to every citrus I bought regardless of seller regardless of soil.
Except a few, one kaffir with extremely dark green leaves that had some cold damage (I had to prune off the dead parts) but the plant did never drop a single leaf, not even now in the sun and this plant is in the same soil as all the others, had the same nutrition etc etc.
And the ones I bought from lebmung, they're also well conditioned and are in excellent condition.

[Millet]

I  don't think the slow release fertilizer had anything to do with it.

[incubator01]

sorry to seem spam-like but I also noticed for some time that the first shikuwasa I had, had green/yellowish leaves, but soon he started to grow a lot of new ones and right at the same time all other mentioned plants dropped their leaves, this shikuwasa (came from oscar tintori) started dropping his yellowish leaves too (they turned more yellow over time).
Not sure if it is related to the heat or if there is any kind of connection, but if the other plants would have plenty of new growth like this shikuwasa I would be far less concerned.
The second shikuwasa I ordered from them looked very green and lush, and he didn't drop a single leaf.

Is it that kaffir and kumquat are more sensitive to things I do  not know of that other citrus have no problem with?

[incubator01]

Well, what is for sure is that this second kumquat has burn spots on his leaves, guess he couldn't handle the noon sun, and these are supposed to handle 38+ °C?
Am starting to think this plant was not good from the start, it arrived in heavy clay soil which was my first from tintori, had to wash the roots completely when it arrived and replace with better soil.
But then it stood outside, not in the sun because we had a lot of cloudy weather, so i thought  that was ideal for him to adapt. then the sun came and once it got to 24°C (weather report temp) things started to get bad....

[MisterPlantee]

How big are the pots compared to the rootball? For me I have found that Kumquat seem to be sensitive to too much water more than other citrus that I have. Citrus also like to be rootbound somewhat so I try make sure the pots I use don't have too much free space when I repot.

[incubator01]

How big are the pots compared to the rootball? For me I have found that Kumquat seem to be sensitive to too much water more than other citrus that I have. Citrus also like to be rootbound somewhat so I try make sure the pots I use don't have too much free space when I repot.

The potsize is indeed too big, it is double of the size it came in, but regardless I do not water it more.
I give in full summer (now; when it is warm, hot , sunny etc) 1 liter of rainwater / week which is being absorbed nicely,  one of hte kumquats I removed from its pot and noticed the rootball was still very small, i planted it in full soil in my greenhouse and there it is growing nicely.

The other one is still trying to recover from the hot weather in its bigger pot.