I would take cuttings and try to root them. Then I would prune it back to green wood, remove all of the dead wood. Buy some SuperThrive. Some people call it snake oil but I believe it is good stuff. Give the cal a dose of Superthrive and 1/2 strength 20-20-20 miraclegro type fertilzer. Buy one of those halogen shop lights (less than $20 at a big box store) and turn it on the cal. It provides warmth and light. Good luck

Suzy, congrats on the length of time you've had your Cal. I'm really impressed.
Have you ever repotted or added new soil to this tree? If not, I'm sure the soil compound has changed so it may need adusting. Your cal has been around a long, long time.

If leaves have been nibbled, then you can bet there is some type of unwanted pest.. Inspect thoroughly. Look for webbing, (mites) white patches (mealy) and lumpy bugs that can sometimes be hard to spot..(scale) This last bug sometimes looks like part of the stems..You'll find them underleafs, atop leaves, and on stems..If they can be scraped off then it's scale.
Do an inspection and let me know..

I agree w/TSMith about SuperThrive..it's incredible stuff, but if bugs are on plant, other than insecticides, nothing wil help.

You can take cuttings, but unless you graft, it'll take years before fruiting.

I'd also mist leaves daily..Do you have a humidifer? Have you changed 'anything' than previous yrs?

Sounds like you're watering properly. I've read never ever give an ailing plant fertilizer, but perhaps if you give a mild dose it won't harm your tree.
May I ask why you prune? Sometimes pruning can interfere w/blooms/fruiting. For a plant as old as yours, it shoud be taller?
Oh and speaking of growth, what size pot is it in? And what material? clay, plastic, ceramic?

The only thing I disagree w/LSmith is, I believe CAls prefer cooler winter temps. Extra lighting will help.

Is your soil well-draining? When you water does water sit atop soil or drain? I'm sure you know constant wet soil will harm a plant and rot roots.

Check your tree and let us know if you find anything..Toni

If you knew what a black thumb I have.....keeping this thing alive for so long is just short of a miracle.

Did a search for bugs when it first started to lose an unusual amount of leaves. I did another one today. I looked on the plant, in the soil, on the trunk and near the roots...nothing. Other than a few (10, maybe) leaves that have been obviously chewed, the only other thing I found was on two leaves the leftovers of some type of cocoon. This could be leftovers from it's days outside. I did spray it with a mild insecticidal soap before bringing it inside.

The pot (planter) is plastic and quite large. The tree has been transplanted many times as it has grown and new soil has been added. The water drains easily. I water until wet and then let the soil dry out between waterings....have followed this approach since day one.

The fertilizer I use is specifically for citrus trees. I use it before flowering and then a few months after fruit is picked per instructions. The last time I fertilized was actually mid summer.

I have been misting the plant for the past month or so. I have never done this in the past.....but was trying anything to help the ailing plant. The plant is at about 65-68 degrees. It is in a south facing window. This is the same place it has been for the past 4 years during the winter.

The pruning seemed to really help the plant...and was only done every few years when it had lanky branches. It is 3.5' to 4' tall. My guess w/o pruning it would be 5'. But realistically, that would be too big of a plant to manage seeing as how I need to be able to move it in and out each season. It has been 3 years since the last pruning. The tree this year (prior to its sudden demise) was covered in flowers & fruit....and has been very vigorous for most of the past years.

Whatever it was that struck this plant, it seemed to happen rather suddenly after it was brought in the house. Its weird, but after so long.....I thought I knew this plants likes & dislikes pretty well.

I did pick up a bottle of SuperThrive at the plant store today. The guy at the store also spoke highly of it. He suggested a mix of 20% bleach and 80% water to kill whatever is causing what he thought was a root problem. Then let the soil dry out thoroughly (I also see this moentioned in the FAQ). He seconded the opinion that dead wood should be cut back to green. He said he had not heard of a rooting being started on a citrus via a cutting (??)

So, this afternoon I cut back the dead wood and removed any on-their-way-out leaves.

Dang, I wish I had saved some the first fruit to fall off the tree. There are two volunteers in the pot...but they seem to also be affected.

Thanks for any suggestions....advice....etc!!!! I have a halogen light....which I'll move over by the plant.

Suzy, I don't understand..this cacoon you mention..is it from a house spider? I'm assuming it's still in the tree or did you remove it?
If it's on the tree, get a white sheet of paper, place under the leaf or a group of leaves, tap leaves while holding paper under..If you see little speckles these are mites. Depending on your eye site, you may need a magnifying glass. They also come in a variety of colors.
Suzy, if you're seeing bitten leaves something is at your citrus..do you have pets like birds? Cats and dogs would do more damage than small bites. Birds are a different story. Toni

What I said was "leftovers of some type of cacoon." It is the white web type stuff. Whatever was in it is long gone. It was on one of the leaves that fell. As I mentioned, there are no bugs on the plant at this time. No mites.

Keep in mind that the plant spend the entire summer outside, so some bugs are bound to be on it during that time.

No pets in the house.

Think I will go with the plant store guy's advice regarding root issues. Seems to make sense.

Thanks for your help.

Suzy, I know the white stuff you mean..I too take plants out for summer and really have to hose plants to rid bugs such as spiders, yuck and ear wigs off the leaves..
It's a lot of work, but I know how much plants like to be summered outside, so worth the work.
Good luck and I hope you can figure out this problem..Toni

Suzy, I know the white stuff you mean..I too take plants out for summer and really have to hose plants to rid bugs such as spiders, yuck and ear wigs off the leaves..
It's a lot of work, but I know how much plants like to be summered outside, so worth the work.
Good luck and I hope you can figure out this problem..Toni