Spider mites, poor soil, too small a pot, not enough fertilizer, not enough light (from what I can see from this limited single photo). Definitely treat for spider mites and address the other issues.

Patty S.

Yes, a really bad case of spider mites. You can see the webbing they produce at the tip and at the stalk of the main leaf.
Immediately, take a damp, soft cloth or sponge and gently wipe both surfaces of all remaining leaves. This will remove a good percentage of the mites. Then buy and treat with whatever spray claims to be a good miticide.
Then check everything else mentioned by hoosierquilt - but you need to get rid of those spider mites first!

Dido to what Patty has mentioned Get rid of the spider mites soon because your tree will probably try to grow in the next few weeks and the spider mites will end up massacring all your new growth.Give your tree a good wash that should help.Do you tend to over water or under water your tree? If you tend to overwater I would then repot in the spring in a nice soil with good drainage because if you over water now then you would probably over water in the larger pot and end up killing your tree.If your tree is always dry I would repot now .

Thank you guys so much.