Need advice on Dwarf Meyer Lemon Tree

I purchased a 2-yr old dwarf lemon tree and have had a year.It is in a container and never been outside. Initially it was doing well and produced 2 lemons. Late summer it started to ooze a clear sap. I cleaned the entire tree, soil and pot and it seems to be doing okay; however, it now is dropping all its leaves.

It is a bright green tree with 4 leaves(as of this morning). I notice the trunk/branches are not as thick as the lime tree (purchased the same time).

What can I do to help the lemon tree 'bounce' back and thrive? I have a moisture tester so I think it is being evenly watered. I just fertilized it a couple weeks ago.

thank you for your help.

Hmmmm...
I had a citrus seedling, maybe a lemon, maybe a grapefruit ( I grew it from seed) in a pot in Dallas for maybe eight years. It got brown scale and dripped honeydew. Check for scale insects on the branches, that might be that causing the "sap" drip. I had to (gently) rub them off with a paper towel, then spray in the spring when I moved the tree outside. BTW, you should move your tree outside as soon and for as long as the weather permits. That'll help fortify your tree... They aren't house plants unless you have a real greenhouse. Also, I believe you need bees to pollinate your flowers. You might need to do that on your own. Take a new, clean, soft brush and take the dusty pollen from the flowers and transfer it to the sticky pistil of another. Keep your fingers crossed and look for baby lemons. If you get a lot of lemons, the tree will self thin the crop.

I have a dwarf and a standard improved Meyer here, but they stay outside in my San Francisco, CA climate.

I agree with AresDraco about the scale. I live in Massachusetts and have been growing Meyers Lemons in pots for about 10 years, not terribly successfully, but I'm still at it, it's a challange I refuse to give in to. I have the same problem with the sticky sap every winter. It's very tiny scale bugs. I used to have a large tree which I would put in my large walk in shower and wash. If you get a mild day you could try putting it outside and spraying, I've been using Neem oil. It hasn't totally eliminated the problem, but it's better this winter. I also have a new, smaller plant this year, I accidentally let the root stock take over my lemon tree and the lemons that I started getting weren't Meyer's at all, but a large lemon that my father said looked like a Ponderosa, so I ordered a new one to take it's place. This one is only about a foot high, and I can put it in my kitchen sink and wash and hand pick off the scale. I also ordered some key limes with this new one, and actually they are having a worse problem with the scale this year.
I also agree with Ares about putting it outside as much as possible (although I see you live in a much colder zone than me). First, the scale problem goes away (beneficial insects or birds I guess) and second, the leaves get much greener and healthier. Meyers lemons can take some cold, so I put mine out as soon as my last frost date has passed, even if it's a bit chilly out. And mine do drop their leaves when I bring them in for the winter, I think it's just an unavoidable adjustment. I do try to gradually get it used to it's new environment, but it usually still drops them. They need quite a bit of water.

Thank you AresDraco and cindyeo for the information.
Since it dropped its leaves there hasn't been much growth but I think it is too cool and maybe dormant. I am going to let it go and in spring put it outside and see if there is any change.

you wouldn't expect growth this time of year, it might start in the early spring inside your house, but you probably won't notice much until you put it outside. That's when mine gets nice and full and green.

Since it had dropped all its leaves I re-potted it to a smaller container with new soil. I pruned it. It has 10-12 new shoots and is doing well. I can't wait for warmer weather to see what progress it will have.

Thanks for all the advice.

I'm glad it has new shoots.

Place it outside as long as temps don't drop below 27 degrees and don't over water it. (I have had mine out in 21 degree temps). Allow drying out between watering. Spray with a mix of Safer's soap and horticultural oil mixed. But don't allow direct sun when spraying this solution. It will burn the leaves. Fertilize in the Spring and late Summer with Citrus food only. It will blossom around February-March after about 3-5 years of starting from a cutting. They do need to be outside for maximum growth and cross pollination. Also the stems of lemons are not as thick as that of limes. They are so wiry that mine get weighted down when the lemons are produced. I repot about every 3rd year after trimming the root sides and bottom 2" in the same pot after reaching the desired height that you wish. But the worse enemy is saturated soil. They will stand almost like drought conditions. The leaves will droop when they are approaching too dry conditions.

Thank you everyone for the advice. I live in zone 4b - - - last week we were minus 27 air temp and wind chill minus 50 so it will be awhile before it is outside. I have been fertilizing it on a weekly basis and it is doing wonderfully, a lot of new growth. I can't wait for Spring/Summer to see what it does.