The air temperature shouldnt be a problem , im running just on 85 to 90F air temperature most days here with windows closed, i have found other years the cold breeze coming in can be a problem, i do run a humidifyer though to keep the air damp
i leave a door about 3 inch open to prevent the room becoming an oven

The high temperature causing it will probably be a lack of humidity or just they are not used to the temperature

It could be the root temperature, are you using a heater mat?, the roots need to be warm, its suposed to be minimum of something like 65F ,with no heater mat, the roots will probably be too cold, even though room temperature is fine

i found also if the roots are on the bottom of the pot , with the heater mats on, the leaves would fall off when the roots were on the bottom of the pot, i presume they dont like direct heat on them, once repotted the soil can be run at high temeprature,
i set the soil around 88F , but it varies between 80F and 95F at the bottom of the pot (1" up) , but at the top of a 10L pot the soil temperature is only 68F 2 inch down from the top, in a room with air temp of nearly 90F

Dont forget to fertilise them as well as normal, maybe with slightly lower nitrogen if they have fruit on them, with the lights and heat they will try and grow , if you have knocked the fertiliser back because it is winter, they will be under nourished and leaves will yellow and fall

It sounds also like a mineral deficiency. Does your fertilizer have added trace minerals? If it were me, I would give them a feed of epsom salts and see how they go. And some iron maybe when winter is passing.

Well, they were fine until the temperature got as high as it did. Even outside the whole month of September and 1/2 of October when the nights were in the 40's. They were as healthy as coulb be even when the temps only got as hight as in the 60's for over 3-4 weeks. SO I doubt it is lack of heat in my room. I have a tree that use to grow at work where it got as cold as in the 40's when the heat turned off at night, and as warm as 75 when the heat went on with no humidity. It did get FULL sun though even all winter and never lost a leaf after bringing it in last winter.
But for sum reason, when the heat rose in my room, wow!!!
Do you think it is a lack of the sunlight they use to get.
I fed them with great fertilzer with micronutrients all summer, and even still do, my fertilizer regimand has not changed.
I am wondering if it could be just lack of sun and or lack of nutrient take up because of lack of sun. I am not sure.
I just want to stop my leaves from going from dark green to pale.
Any other ideas. I hear everyone just about goes through this when they are bringing them indoors from the outdoors.

What type of lights are they? , flourescent type (house or plant type) or hid (sodium or metal halide) etc , if they are growing lights then the lack of sun will not be a problem as the spectrum of light and intensity will be high enough

It is probably the root tenperature not warm enough as the room warms up and the lights are on, strong light or heat and cold roots will give leaf drop , if you keep the roots about 70 to 80F you wont have a problem or have cold roots and no light/heat

It could just be they dont like the move indoors, a bit of leaf drop due to getting used to it,

i have had no leaf loss on bringing into the house, when using the heater mats, in room heater ,growlights and humidifyers
with just the lights i had a bit of leaf loss , but not much

hum....Does this mean that if I can't use heat matts on all 15 of my citrus, I should cut the lights down since my room is very cool all winter?
You are right about the lights though, they are metal and halide and the room does warm alot with them on all day. Especially when I shut my windows soon for the winter. Right now my windows are still open and I shut them at night if temps drop low. The temps in this room does go down into the 50 to 60 range in winter especially. But just one day with the windows closed, I can walk in and it feels so hot and humid in there. 80's the other day, and that day, I lost alot of leaves.
Should I cut my lights ,if I do not plan on keeping my room very warm?
I would appreciate your help before I loose all my leaves.
Maybe the lights are too warm and on too long after the roots have been cooled all night?
Thanks for your help?
What would you do if you were me. I have them in south facing windows all sharing the sunlight, in which I am afraid there is not enough. Would you put lights on? keep them off? Less light is better if I plan on keeping room cool?

Until someone chimes in..My lites are of for now.
Thanks

I brought in my key lime, my lemon and my blood orange. They didn't get enough light and they are all losing their leaves. The lemon is losing the biggest older leaves, but I think it is because they are all getting a lot less light. The blood orange started losing almost all its leaves, until I read a tip on this forum to mist the leaves, and that worked for the orange. Not for the lemons or limes. I don't have any of them on a heating mat, btw. They did the same thing to me last year, as far as losing leaves, the only diff between the citruses is that the lemon and limes leaves yellow and then drop off, but the blood orange just drops the leaves, no yellowing at all. They are all in a south facing window. I haven't put them under lights yet, my husband has wiring to do.

Just putting in my 2 cents.

I have two citrus: a small Meiwa Kumquat and a Bearss Lime. Both have lost a few leaves since being moved inside. The Bears Lime has lost some lower leaves that were not getting enough light. My Kumquat has the shape of an African tree - very horizontal - and has not lost its lower leaves but has lost a few leaves throughout. In both cases, the dropped leaves were green, not yellow, and leaf droppage has definitely lessened. The only time I experienced dropped leaves that were yellow was when I had a Meyer Lemon a year ago, which I think I was due to over-watering. I am following Toni's advice and spraying my citrus at least once a day and also adding epsom salts to my watering regimen. Seems to be working so far...

Update!!!!
The leaves on my tree have stopped falling!! I found out that someone kept turning the lights off in my room while I was at work the whole time. Since I put an end to that, and since the lights have been onlonger now, not only have I stopped loosing leaves, but my Gardenia has greened up and opened a new SWEET smeling flower, and my trees have new flush with flower buds, especially my grapefruit tree now.
Someone on one of my posts really helped me with understanding when to use lights and at what temps in my room where as not when not to use them also. I decided to use them since I love to see healthy growth all winter.
I am so happy we have each other to see us suceed. We will definately need each other through the winter. Now I understang cold enviroment verses less light, and warm enviroment verses more light. Since my sun room gets warm and humid by day, and never gets cold at night, I keep my lights on for more than 8 hours a day plus my plants are in south facing windows.
I would say while we figure out what conditions we set for our trees, and then establish a stable enviroment, it is going to be common for us to loose leaves until our trees are totally comfortable. I guess I found that point. I hope you all do to. For some reason they respond alot better when we put them outside as to bringing them inside.
I grow plumerias, and I am so glad that the leaves on my citrus don't fall off like they do on my plumies because of shorter days, or my trees would be bald. So it is no suprise that our trees don't suffer in some small way. Don't it make you wish you live in a warm climate!lol

Don't always assume it is just overwatering, for I have mine growing in soil which doesn't allow room for that. In fact my soil dries out almost to fast. But soil temperature in the pot, temps in a room,roots being to cold while the top part of plant is strssed from to much light for the roots to cool leaves off so they won't overwork and then fall, how much light we provide, adjusting to a new enviroment,a different feed program, and even insects can all play a role in leaf drop. But once you make a check list of all, and set things straight, our trees reward us with that extra step we take to love them. I would have to say they are like people too, the only difference is, is that they can't talk to us and tell us what makes them uncomfortable, so we have to be in tune with them. This can be a rewarding challenge. But truly a challenge, if you havn't lost your leaves by the time you figure it out!!lol
I hope everyone here has a sucessful growing winter season, and P.S, don't forget to watch for pests, and clean your trees as often as you can, especially when it gets warm enough to spray them outside with a good stream of water. Also, Toni's natural pestcide really does work!!
Mike

One more thing....DON'T BUY ANY PLANTS AT ALL UNTIL SPRING! at any greenhouse. We take pride in cleaning our plants, keeping them pest free for the fall move indoors. And these greenhouse do not. Last year I did this, and had pests all winter. This year not learning from my mistake last year, I bought a beautiful unique jasmine on Saturday, brought it home, washed it, sprayed it and let in sit in another room for a couple of days. Guess what I found on it? Mealybugs!!
I brought it right back. So don't risk the health of your plants with foreign ones until you can make sure the new ones are clean. Better yet, don't buy until next spring! You never know what pest you are bringing into your home for a winter vacation in your home!!
Mike

Lighting has not been a problem for me; maybe that is because I keep my townhome temperature no higher than 68F. My kumquat is by a window facing south southeast; so it gets quite a bit of morning sunlight. Plus I supplement with a grow lamp. My Bearss lime has the same window exposure but is one floor above the kumquat. No grow light on the Bearss lime. Nonetheless, they both seem to be getting enough light. Even in the summer when I have my citrus outside on my balcony, they don't get any more than 6 hours of sunlight a day... As long as they make it through the winter, I will be happy.