Thanks for everyone's response :) Hi meyermike_1micha, I know I overwatered from having the pot sitting on the floor with a plastic water catch thing. It sat in water for a bit before I had someone help me get it onto the rolling crate that it now sits on. I did notice one really small bug by the underside of the pot when I was flushing the soil. But other than that, nothing else. As far as freezing, I don't think so. I brought the tree into the house early October, but there were a couple of nights the temp. was around 45-50 degrees, so maybe that?? I had been watering it once a week, with 1 pitcher of water until the time that I watered with an additional pitcher (which I thought it looked like it needed) and then discovered the extra water in the base pan the next day. I am an inexperienced gardner and have no idea what to do other than getting some additional lighting (grow lights??) Should I flush the soil again, just in case my cat had pee'd in the pot? Should I give it some kind of food/fertilizer?

Kev, that's it..5-1-1 FE has an odor, should have warned you..They also sell odorless, which, I think, not sure, contains parsley flakes..You can find it on Ebay at a decent price..Homeharvest.com sells an odorless, or did..it's been a while since I've checked their site. If you spray plants outside the odor won't matter..indoors lasts about 2 days..If it's warm crack open a window. Candles, incense, and/or air freshioners cover the smell. The good thing is, it's not harmful..So safe around kids/pets. If it does the job, it's worth a couple days sniffing fish..if you're a fish lover, it won't matter..LOLOL..Toni I use 1 capful of FE to a gallon of water..mix/shake thoroughly..place in a clean spray bottle..use after mixing. Don't let it sit overnight..Any fertilizer, be it chemical or organic is not to be used if sitting longer than a couple hours..so don't pre-mix. Good luck, Toni

Okay, all excellent advice from both cayden and always from Jean. Additional suggestions: You need to drop crotch prune your tree, as it's getting just too tall. Lemons are notorious for sending up these vigorous water sprouts, so take the tree down in height using drop crotch pruning. If you don't know how to do this, see if you can find a GOOD tree pruning specialist who knows how to do this correctly. Your tree's root system is going to be challenged due to all that concrete, so keep the size of your tree down. Plus, it makes it safer to pick your fruit. Next, you must minimize the pool splash. That chlorinated water is bad news for the roots. Get to a good quality garden center and buy a high quality citrus fertilizer (I would suggest GroMore Citrus & Avocado Food) and apply once a month until you see your tree starting to respond with new flush. Don't be surprised if you see the older leaves drop, that's fine, just look for new flush. Once you see new flush, you'll be able to cut back to fertilizing once every other month. Use at least the amount recommended for the size of your tree. Lemons are heavier feeders than other citrus due to their prolific fruiting tendencies. Treat for ants to keep out aphids. You can remove aphids if you see them in the spring on the tender new growth by hosing the tree off with a hard blast of water. We talk about CLM constantly on this list, so just search for CLM or Citrus Leafminer on this forum. I think I've posted about 6 times in the last week, so not worth re-posting the same info :-) Besides, too late to treat from CLM at this time, you're seeing the aftermath and not an active infestation. And frankly, I don't even treat my mature trees, and it really is more cosmetic with an older tree. Don't worry about whiteflies, I've never seen them bother citrus. Lastly, I'd get 2 to 4 bags of high quality compost, and mulch your poor tree, then top with some back to help retain moisture. Your tree needs nutrients. Composting every season will help with any soil pH issues, which really isn't an issue here for us in S. California. Our trees do just fine without an pH adjustments, as our soil pH isn't that high. However, that being said, your soil pH can get higher next to the foundation of your house, from lime leaching out from the concrete. I also see some snail damage, so put down some Sluggo around the base of the tree (safe for kids and pets, fatal for snails and slugs.) And, the fruit split is due to uneven watering during our really, really hot summer and fall.. Just pull off the split fruit, it will attract insects and infection. Patty S

Evidently the friend looked at it differently. Was the tree removed to his residence. If so, the loss of leaves is a common result of a changing environment. I suggest you not change its soil until the plant is ready to add new growth. Then, changing its soil and possibly going up one size of pot, will add to the encouragement the plant will use for spring growth. AT this time, follow what fertilizer regimen you have done in the past. Citrus are heavy feeders and, much like the African Violet, can be fed with every watering. A fish emulsion or high potassium fertilizer can be given. Sunlight at this time is very low and your citrus will benefit from being given as much, and as equally, as possible. Place it where it can receive the best light...a southern or western exposure and turn it 1/4 turn every day or so so that the crown receives all the sun it can use.