My primary concern is also the potting medium. Plants grown in containers require a very freely draining media that typically includes NO soil (proper potting soils are generally referred to as "soil-less" mixes, as they contain no actual soil or dirt). Readily degradable materials like grass clippings or compost are also not recommended nor is sand unless a very coarsely textured grit. The Container Gardening or Citrus forums should provide various recommended recipes.

Also anything grown in a container requires a thorough watering when you do water. No "sips"!! Water thoroughly until the water runs freely from all drain holes and then tilt the pot to allow any additional drainage. This will flush out any salt build up, which is common with containerized plants. Water again when a 'tell' (a wooden dowel or chop stick inserted down into the pot) comes out as mostly dry. Don't allow the soil to dry out completely but also do not overwater.

Fertilize frequently during the primary growing season as every watering will leach out nutrients. Use a fully water soluble or liquid fertilizer with all necessary micronutrients and apply it weekly, weakly (half or quarter strength, according to label directions).

Gardengal and Ken said everything I was thinking. Don't be afraid to keep the lights on for at least 10 hours and lightly fertilize once the mix is taken care of)

Thanks so much, everyone, great advice, I’m ordering peat mix now. The hamster bedding is aspen wood shavings. I’ve noticed gnats and organisms in/around the pot (perhaps from the summer’s compost) and was being cautious. I have radiators which are dry hence the humidifier. I give it a thorough watering when the the meter is at a “2.” The weird way it’s expelling it’s energy is confusing, I’ve heard mixed things on pruning tree less than a year old.

If you've seen gnats, mosquito bits applied to the soil every 14 days or so plus a dusting of DE to kill adults will take care of that. I second everyone on watching your mix, if you're new to this I might shy from making my own mix and get a bagged blend with good overall ratings. That can take the guess work out of it. I might wait to see an improvement before you start fertilizing, a good mix should have what the tree needs and fertilizer can add further stress. Watch your watering and make sure to water deeply. Placing a tree up on plant feet and letting it drain to an oversized tray can help act as a visual on your watering and as long as the bottom of your pot is elevated above the water level, that water won't be reabsorbed.

I wouldn't do any pruning right now, even though some branches have no leaves, they are still green and will most likely put out new leaves during your next growth flush.

The hamster bedding is aspen wood shavings.

==>>> this is probably a big part of the problem .. though im not researching aspen to verify such ....

but .. generally ... raw wood is not good in a pot ... as it breaks down... it can leach nitrogen from the pot.. as well as steal too much water ... not to mention potential causing mushrooms ... which might not be a problem.. but usually not something you want in your pots ...

it also can bind with other things.. ruining the water movement thru the media ..

many mixes including the cactus mix ... have relatively larger chunks of wood.. that does not do such ... such as pine bark ... its apples and oranges ...

when i say a sip of water ... i mean that there is water flow thru the media.. and straight out the bottom ... the tree just sipping as little as it needs.. as the majority flows thru .. and what little is retained by the products in the media that are there to retain enough to be happy ...

as compared to many water loving houseplants ... that are near bog like or aquatic ... and barely mind standing in water that never drains out.. e.g. a pot with no drain hole ... not many.. if any trees like standing in excess water ...

now.. all this said.. from a variety of sources ... basically all agreeing ... you are back to the fact ... that citrus trees are full sun outdoor plants ... and not easy to grow.. indoors.. long term ... one reason for the need for full sun are those huge luscious fruits ... you simply cant get those indoors .. short of a lot of experience.. and a lot of supplemental light ..

my point being.. if you are a bit of a newb... you are starting with one of the hardest plants to work with ... which is probably how most of us started ... but if you fail ... just try again ... and again .... and soon enough.. 30 years down the line.. you will be in some forum.. sharing your experiences and knowledge ... but dont get tied up to much on this particular plant ... you will win.. or you will lose.. and so be it.. thats what gardening is all about ...

repot it in proper media in late winter.. 4 to 6 weeks before it can go back outside .. which would be about 4/1 in our MI [because it cant go out until mid to late may due to frost/freeze issues] ... so that it has that amount of time to settle down from the stress of repotting ... and then take it out into full bright shade ... im thinking your pot might not be big enough for direct sun .. harden it off properly ... or you will sunburn all the leaves off ...

have fun.. and good luck

ken

ps: premoisten and sterilize your media before repotting .. to insure there arent any bugs or pathogens inn it.. easier to start hyper clean.. than to have to fix a gnaty problems ...

https://tipnut.com/sterilize-soil/

Ken,

I agree with you regarding the media and the bugs/pathogens in it, however I would have to, respectfully, disagree on your comments regarding growing citrus indoors. As long as you can provide adequate lighting and pay attention to the climactic needs of your specific plant, it is definitely possible to obtain usable fruit from an indoor tree. (I have actually done so, and have a decent harvest of kumquats that will be ready soon, though my trees have never been outside longer than necessary to wash them down in my driveway -- I don't have anywhere outdoors I could grow anything even if I wanted to). You simply need to take into consideration the variety of tree you want to grow (I, personally, would not grow navel oranges as they take heat to sweeten and I wouldn't want to live in that environment nor pay for the heating bill), but lemons should be able to do just fine. As long as you have good windows that face south, east, or west, and keep your tree as close to that window as you can get it without the micro-climate being too cold or impeding your access to it, you'll do just fine, and can get fruit. (A caveat to that is if you live in a darker house with few or smaller windows, it will be more difficult and the size of plant you can support will be smaller. In this case you'd probably need some kind of a grow-light setup). How much you get is entirely up to your own environment and how you care for the plant. You will also have to hand-pollinate with a paintbrush if you want to maximize fruit production. I think most important is just to have fun, not worry the plant to death, and keep it as simple as possible. Start messing around with changing soil, fertilizer, etc. once you've learned the basics of taking care of your tree where you live. There are also little tips and tricks like putting the plant above the tray on pot feet (bottom of the pot elevated above the water level) and just letting the tray evaporate on its own that can help aid in the specific micro-climate of the plant. And then it is also important not to overcrowd your windows with plants, know what your capacity is and don't go beyond that. There is a pretty good learning curve though, and it can take some trial and error to figure out what you need to do for your, specific, environment. So I think we do agree there.