my lemon seedling is dropping leaves. please help!
I grew this from a seed a little over a year ago, not sure what type of lemon it was though. It seems to be very healthy looking, leaf wise, that is. But all of sudden, starting a week ago, its been dropping leaves from the bottom up. Obviously because of my zone, I have it inside for the winter under an artificial plant light. I had it in a terrarium where its decently humid, and in there it took off. It outgrew it actually. So I ended up moving it out of the terrarium, so then it was just under a plant light in my room temperature room, it wasnt really growing to much at all here. I just recently moved it to its location which you can see if the picture. It gets a nice amount of sunlight there, so hopefully I'll see some results. ANYWAY, it is loosing one of its few leaves a day. I am getting very concerned. I checked all the leaves and they seem fine, but then all of a sudden one just drops. I believe I am watering enough. So any suggestions on what to do or expect? Is it supposed to do this? It is starting to get that barky appearance on the stem from the bottom up.
Also, shown in the first picture, the top growth is very funky. Why is this like this? Should I trim it off? Im guessing its from inadequte light. Thank you so much.