Well, first things first: it's a Dracaena fragrans. I think. The reason why it hasn't attempted to grow back any of the lost leaves is because it can't. All you can do when you're a Dracaena is get taller or branch, and branching would only be likely if it had grown mostly horizontally for a period of time, or if it had flowered. So it gets taller. Is there a way to regrow? Well, kinda. You could cut the plant back, at which point it would be forced to sprout new growing tips. Or you could air-layer (.pdf file) and start over again with the tops of the plants. The more interesting question to me is why you're losing so many leaves in the first place. Granted, keeping your plant alive for two years is an accomplishment in and of itself, but the leaf drop looks like a fairly extreme case of something or another, too. It would like more light, though that's not why it would be dropping leaves. Soil breakdown is a possibility, as is over- or under-watering, fertilizer buildup, and temperature. Pests are an outside possibility, but these aren't really known for having pest problems, and most pest problems would have progressed well beyond obvious by now. So. When you water, do you pour water in until it starts running back out, or do you only add a little bit at a time? Does the plant ever have to stand in a saucer full of water? Is the plant in a draft? Is the plant in the path of an air conditioning or heating vent? How long has it been since the plant got new soil? Is the water in your area naturally high in fluoride? How do you decide when it's time to water? (by schedule? by feeling the top couple inches of soil? by weight of the pot? whenever you remember?) Are there roots coming out of the bottom of the pot? I'm going to go ahead and bet $10 on soil compaction and/or rootbound: that's a lot of plant for the size of the pot it's in. Unlike saucer, I think I would go up a pot size unless you're planning to cut it back, and if it's as potbound as I suspect it is, I might move it up to the next largest size regardless. If it were my plant. Which it is not. Look at the roots first, like saucer said.

I am really surprised that so many seem to be saying that Meyer's is a difficult citrus. My experience couldn't be more different. Mine has been overwintering in a cold garage where the January temps ran from 32 F. to 55 F., it was hardly watered and the light is decent but not intense. It is literally covered with fruit now and is beginning to push active growth in response to stronger sun and longer days. It also blooms throughout the year. Meantime, another Meyer's I brought inside for the winter, is covered with scale. I intend to wash it thoroughly and get it out of the house A.S.A.P.. So far, I would say I have been least impressed with flowering and fruiting (or lack of) of true lemons (not the hybrids). Maybe after a good year, I'll feel differently. Yes, citrus are good about recouping from defoliation. My Persian lime recouped nicely in the basement (under fluorescent) after some problems in late fall--currently in flower actually. Good luck!

What kind of low temperatures are you getting right now? It needs to be outside if you are not having temperatures close to freezing. That will cure you leaf drop. Also your lemons are ripe. I dont know what kind it is or if they hold well on the tree but with just a few and that tree being smaller and having trouble I would remove them. Mike

I have a feeling that your plant, as a new transplant, was not getting enough water. Sometimes when you put a new plant into the ground, the root ball is so tight it just doesn't get the water. So before you put a plant into the ground you should gently loosen the outer roots to encourage them to grow into the ground. Also, any time you do water, water DEEPLY until the roots get established. Chances are the plant will be able to root in some over the autumn and winter and will be okay in the Spring.