Vladimir, I'm sorry to hear that! I wonder what could be happening? You've done everything right. Can you show us pics? I have no idea but can tell you that Alexander has also been dropping lots of leaves that are green. I think I sprayed him with too much neem, too frequently in my attempts to rid him of spider mites. Have you sprayed that tree by any chance?

Here are the pics

Vlad, I have an in-ground kumquat that lost a lot of lower branches last year. It's doing fine now after an emergency fertilization, some MgSO4, and digging around the tree beyond the drip line with a pitch for for aeration. I don't know if any of that helped but it fruited nicely this year. Your tree looks too young to be discarding lower branches as it grows taller? Might be a local fungal infection. I would clip the dead part off...and a little into good wood and discard the dead wood just in case it's fungal.

I'd do what John said also...clip those dying branches back. I can't imagine what would cause that...the rest of the tree looks good, so hopefully it's not a systemic issue. Could it be getting burned by too much heat/sun on one side?

Dieback is not from the sun because it is on all sides.

Dieback and leaf drop might be from root rot, even though I am careful about watering, and in which case a repot might be in order which I would hate to do at this time of year.

I just did an emergency repot of a sweet lime that has been in poor health (light green leaves that started dropping) for months. It finally hit me that it might be root rot and, when I did a bare root into gritty mix, I saw that it was indeed root rot.

I'd bet you're right. That's the one you found this summer on a stroke of luck, right? It's probably been in that mix for a long time. Or did you repot it then?

Believe it or not, if the finer particles have settled to the bottom half of your container while the bigger pieces remained on top, it is very easy to develop root rot, even in the 5.1.1 mix, but less so in the grittier one...

I would find a way to do a 911 in another mix and check the roots, or wick away all the moisture from deeper in your pot Vladimir...Try going back to using the wooden dowel method too and really see how long it take for the bottom portion of that pot to dry out...Sorry to see you have this problem, but you are not alone...Been there done that, even in the gritty mix!

I would not fertilize it all until you know the roots are functioning as they should.

Here's the good news Vladimir..You have a much higher chance success rate than those of growing their indoors since your tree is in a nice greenhouse with as much light as possible and good warm temps..Good luck)

Laura, that is the one I got this summer. I repotted it as soon as I got it.

Thanks for the advice, Mike. Looks like I'll be making up some gritty mix tomorrow.

Hi Vladimir, my trees are losing quite a few leaves the past week or so too. I suspect it is mostly because there is just so little light available up north in the winter. I am even providing some supplemental light which helps but I still lose a few leaves every day but not too seriously yet. I have found that the supplemental light has helped in past years even though the plants are in a greenhouse. We have had many cloudy and dark days recently. Up until now I have been getting lots of new growth and blooms so am hoping the trees are just shedding older leaves to adjust to the lower winter light levels. Fortunately we are down to the shortest days now and the day length will begin to increase again. I expect our trees leaf shedding will start to improve again as the days lengthen and if we get sunnier weather. Sorry to hear you are having problems with your kumquat. My Key Lime from seed is having the most problems of leaf drop of all my trees and my Ponkan is plagued by black citrus mite. I hope they can all hang on through spring. It is a tough time of the year for them, greenhouse or not. It is just so much easier to treat for pests and to water them in a greenhouse instead of in the home. If you suspect root rot, maybe you could try Mike's idea of putting a wick through the hole in the bottom to help dry out the medium faster. Best wishes for the health of your tree.

Cory

Valdimir...Also good news..Since your mix was already better than any fine mix, it should fall gently away from the roots without any stress what so ever and allow a good re pot with the newer mix..

Cory, you are soooooo right! I can't tell you how many days I am having here that seem so dark even when the sun is out...My Kumquat did the very same thing and came back with a fresh set of leaves in the month of March...

How's the patient Vladimir?

Thanks for asking, Laura.

It dropped a few more leaves. I just finished doing a bare root repot into gritty. I removed some of the media from the nursery that was still in the middle of the root ball and loosened up some of the tightly knotted roots as best as I could. The roots showed no sign of rot although the growth medium was very damp. I noticed that the pot was too big for the size root ball and that the roots had not spread out into the 5-1-1 when I had repotted it back in the summer.

Two problems with me putting it into a too large of a pot:

1. I Broke the Four Inch Rule. (See http://www.rootmaker.com/sites/default/files/pdf/4inchRuleWeb.pdf) So I put it into a smaller pot.
2. The medium retains water too long which may lead to root rot.

Too, if you had removed 'all' the older medium from the root ball, finer roots would developed into the 5.1.1 mix way before this..The ones in the older medium were growing while the ones on the outside were not encouraged to grow into the different mix..No problem, nothing you can't fix..I am glad you are figuring all this out Vladimir)

Mike, the old soil was really embedded deeply into the root ball which was a solid mass of roots and I was afraid to do too much damage. In retrospect, I should have been more aggressive at the beginning and removed more of the old soil even if it meant removing some of the roots with it. Perhaps I should have been more aggressive today also and should have done some root pruning????????

Vlaidimir, personally, I would of done what you did if I did not have access to the a mix closer to the one left in that root ball.....Too much root work when a plant is already stressed at this time of the year would of set it back even further...For my trees, the best time to do extreme root work without any ill effects is the beginning of June when my trees are most active and healthy and can take that kind of work..

This time around I would of done just what you did...Great work. Just be careful that the outer layer of the 5.1.1 mix does not dry out faster than the inner root ball mix and vise versa..

Many will just shake off all the older mix and replace it with fresh mix without much root damage and then wait until the best time of the year to do a thorough job.

In your instance, what you did was just fine. but I would of replaced the mix with one that almost matches the one still left in that root ball until I can do a complete 5.1.1 through and through..

Mike, inside the root ball was this compacted, very fine, sandy material. That is the way I got the tree.

Vladimir, my big Nagami is also shedding leaves and has had a few thin interior branches die back. I cut them back today. I am going to buy a few more lights at IKEA on Wednesday to see if I can help them a bit.

Good luck with your repotting and thanks for the very interesting link on the 4 inch rule. So much to learn!

You are welcome, Suzuchan. I do believe it is true. I have learned this from (bad) experience when I put trees in pots that were too big for them and they did not become anchored in their pots because their roots did not spread out causing them to rock back and forth with the wind.