My New Zealand lemonade tree did the same thing so I am watching here for answers. If you use a camera you can take picture that will show up when others click on them.

Thank you. Yes the tree is about 12 years old and this was the first year it ever bloomed... I was happily surprised... I have grown many tropical plants up here in the snow-belt, and have produced a few pineapples and some passion fruit, and my bird of paradise blooms every February, but this was a first. I was so happy, then this started happening... I will take your advice and water it good, but I'm a little worried to do that because when all the leaves fell off originally, it was right after I did that. As far as it being hotter towards the ceiling, this is probably true, but not by much... Maybe a degree or two. Didn't seem to affect it for the first half of the winter... But thank you... I will try.

OK I watered it again until it came out the bottom... I'll keep my fingers crossed but like I said, the last time I did this is when this problem began... But then I got so worried about it I didn't water it for a while, and that probably wasn't good either. And I am absolutely certain that last summer, over-watering it is what caused leaf drop at that time because the saucer the pot was standing in was holding in the water and the dirt got soggy.. I will keep you posted. I hope this helps and doesn't make things worse...

I also put it on the seedling heat mat. That really seemed to help one year. I read somewhere that if the soil is cooler than the air around the tree it causes the roots to be cooler than the tree and that this will cause the leaf drop.

Hi slice4444,

did you check for any pests? Scales, spidermites, etc..

Those top leaves are still not getting enough sunlight or artificial light for the high temps you are keeping it. I would not be surprised to see it drop many more and many branches die off. The only part of that tree that will survive is the leaves getting the most light and the roots being supported by those leaves.

Now while in it's weakened state, I too would watch for pests, for it is always a thing that goes hand in hand in the winter on weak growth.

I would of cut it back like it was suggested so that the whole tree could get proper lightning. if you take a closer look, the only ones doing good are the ones getting the most light.

Too, you could just stick it into a cold room where temps drop below 55 and the leaf drop should stop right away while the trees rests until the sunlight becomes more abundant and when you can slip it outside when temps rise above freezing for a few hours of good sunlight!

The next time it gets into the 40's which is what I would do, trim the top off, rinse it well with the hose and let the sunlight from winter get to it for a bit.

What part of the world do you live in in case I over looked that? What Zone?

Slice4444, from reading your post, I don't think the actual "over watering" had anything to do with the original cause of leaf drop. Rather, I think the cause was letting the tree set in the water that had collected in the drip tray. After you watered the tree, and then let the tree remain setting in the tray's over flow water, it was the collection tray's water that made (kept) the root zone soggy. If you use a tray you MUST remove the pass through water from the tray as soon as possible. Leaving the tree set in that water is a real NO NO. Lastly, have you ever put a thermometer at the ceiling so that you actually know what the temperature is? You know there is a reason why only the leaves near the ceiling were discarded. In Mike's post above, where he states putting a citrus tree in a cool room can help to stop leaf drop is also true. This is because a cool/cold tree has no need to transpire as their leaves are not hot. In a cool atmosphere both the tree's root zone and foliage are both cool and are in balance. However, doing so will also stop , or greatly slow down any possible growth of the tree.

Right on, Silica! Very good points on overheated top canopy and tree sitting in water.

Thank you for all the comments.. I am in zone 5a.. I agree that the top isn't getting enough light.. The tree is so tall I can't get any light above it so I will take off the top either this summer (If it is totally dead) or in the fall before I bring the tree back inside... (It will be too tall anyway) But I brought the tree inside in September and those leaves didn't fall off until January... In fact it bloomed up there at the top in December - at the top, right where it wasn't getting enough light! Like I said, all was good with this tree until I watered it heavily... And it wasn't sitting in water (this time). I know this because the saucer that it's sitting in leaks, so I have to mop up the water that comes out the bottom. I have looked at the tree pretty closely for mites etc. I don't see any but I'm not sure exactly how to find them. I'm not even sure if spider mites or scales bugs even exist up here in Syracuse, NY. I really don't have a "cold room" to put the tree in. I live up north and if I allow a room to get cold somehow, it would drop below freezing and pipes could burst... But in the Spring, (like mid-May) I can bring it back outside and the nights get into those 40 degree temps at that time so that's when I could trim the top and hose it down. The heat mat seems to be helping... I only found 6 leaves on my floor this morning... So I think it is important to keep the roots as warm as the tree... I will have to buy a thermometer to measure the temperature at the ceiling. But it's not hot up there and as I stated, this leaf drop was recent and the tree has been inside for 5 months, so if it were the heat it would have happened in October when my furnace was starting to kick on. Thank you everyone!

THIS is where I live!

Despite the trouble with the tree it looks very beautiful where you live.

Silica has many good points! And I must agree with Petuniafish that despite your issues, it is quite the tree. I hope it responds well to all of our ideas...Please keep us updated as you did today, ok?

Mike

The leaves stopped dropping! - Here is my theory now - and it has to do with the heat mat.... As Silica inquired about, the heat of my house towards the ceiling is likely slightly warmer. This got me thinking.... If it is warmer towards my ceiling, then it is likely even cooler towards the floor.. Not by much but by a little... It wasn't an issue for months because the difference was so slight.. But as soon as I gave the tree a heavy watering, the wet soil took on the temperature of the air around it. And since that air was slightly cooler, the water chilled those roots down - thus causing that leaf drop. That is why I was fooled into believing that the water caused this.. It wasn't the water, it was the temperature of that water.. That is my guess... My analogy is this - My house is kept at 68 degrees in the winter. And I can walk around all day in my bare feet at this temperature, no problem. But if I put my feet in 68 degree water overnight, I would get hypothermia. I'm not saying my hair would fall out but I am saying it would slowly kill me. So from now on, when this tree is indoors, I am putting it on a heat mat. I will try and water it moderately instead of too much, or too little... And if I see leaves falling out, that heat mat is getting plugged in immediately.

At 68 degrees floor temperature your trees roots should do just fine. If you heat the roots up to your own core body temperature the tree will die. Trees operate at a much lower temperature than humans do

It was an analogy.... I didn't heat the pot to 98.6... The heat mat is made for growing plants... My house thermostat is set at 68... But - if you have read the above posts - I'm being told the air is warmer at the ceiling - so I'm assuming that at the floor its colder... And so far my assumption is correct because the tree is doing better.

Citrus grows well any where between 70 to 90F.

So here is my update. The heat mat really helped last winter, and the leaves stopped dropping for the most part. I tried not to over or under - water it. This spring in May, I took the tree back outside and gave it a good watering. Last year when I did this it really came to life and tons of new leaves started to bud out. But this year, it began to suffer again. The leaves started to curl up and fall off and turn a little yellow. We had some cool nights, so at first I thought that was the cause. It also had to get used to natural sunlight again. I have noticed with my other tropical plants (especially my banana plants) , they tend to get a little sunburned at first. But I read somewhere that citrus trees are tricky to diagnose. This is because the leaves often curl up after a good watering, causing you to believe you have over-watered it and this may cause you to stop watering it because you think you are hurting it by doing so.. But the truth may well be that it was under-watered.. The symptoms of under-watering sometimes don't show up until you water it correctly.. The reason I'm saying this is because when I noticed the leaves curling, I stopped watering it and it got worse. As soon as I resumed the watering, the leaves that were left (and hadn't fallen off) perked back up.. So watering it is fine, just no saucer anymore while outside. Sitting in water is bad... I also trimmed off all the dead branches from the winter that died. So, it seems to be doing better and as the summer heats up, I am hoping to see some new leaf growth. But anyone that is experiencing leaf drop for an indoor tree in the winter, I highly recommend the heat seedling mat and adequate watering. I am convinced the heat mat is what saved the tree. I likely didn't water it enough though, because the saucer that it was in (when indoors) was cracked and I didn't want water to warp my floor. The tree needs to get enough water that you see it come out the bottom. It is still bad to have that saucer full of water so be careful. A little excess water is ok though because the heat mat will help it evaporate quickly.

I, too, use a heat mat on my indoor trees. I do not use one on my trees in the greenhouse.

Slice, if it was my tree, I’d check the roots for root rot. I know that’s no easy feat with a tree that size. You mentioned that you repotted not that long ago. Did you bareroot it? What is it potted in?

Not sure what it means exactly to "bareroot" it. I assume that it means put the roots in the dirt, but what is the alternative to that? I used potting soil mixed with perlight and a little sand. I also put 2" of gravel at the base and made sure there are holes in the bottom to let the water drain.

I have not used it on 5 gal pots. The heat mat is nothjng special. This is it: https://www.amazon.com/gp/product/B013HFKRKW/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I don't use a heat mat on mines and all of mine are absolutely fine unless they get too little sun. Now the lack of sunlight is a whole different story..They don't make a heat mat big enough for any pots bigger than a one gallon and only one at a time. I would have to buy several for all the huge pots and little pots that I have.

I too suggest doing a re pot since it sounds like the roots are suffering. Using the heat mat might of been coincidental to the leaves stop falling. This can come in stages. Your air temps in your home should be fine enough for the roots of your tree unless you have to wear jackets inside.

A bare root is basically taking all the old mix off the roots completely but gently.

Mike

Ok then I "bare-rooted" it last summer, pretty much anyway... I cut 4 wedges out of the roots and brushed off as much soil as possible and added new potting soil, perlite and some sand. The seedling mats I have are about 21" x 21" and made by a company called "Hydrofarm Horticultural Products" (Picture attached). If it's a coincidence that it helped, it has been a coincidence several times. But I do agree that lack of sunlight and water are also issues when it's inside. But I really think it helps to get the dirt up to a warmer temperature since the air at the floor is slightly cooler than the air up by the ceiling in the winter (since heat rises) , albeit slight.. I have read that citrus trees really don't like this and have a hard time sending energy up to the top leaves... I don't use these mats on all my plants, just the ones that seem to suffer more. I have 15 large plants and only 2 heat mats.

Slice, I agree with you that the heat mat was probably responsible for the plant getting better for the reasons you give.