Can you take a very close up of that mix?

It sounds liek to me that the mix is not allowing the roots to thrive which in turn is bringing on pest populations.

Have you checked what is going on under the soil line? Like pull it out of the pot and maybe post pics here?

Usually a lack of sunlight, temps to warm for such a lack of light, a water retentive mix, suffocating roots, and salt damage from tap water and fertilizers and other addictives to such a fine mix can kill a tree rather rapidly.

Have you been using tap water?

Have you been watering so the the water comes out freely from the bottom?

Can you push your fingers almost down to the retentive water level? Like beyond the root ball?

Have you been fertilizing?

Can you lift the pot for weight to tell when to water? Does that soil seem to be compacted at all?

If it were my plants I would do a 911 soil mix change into a fresh mix until I could do a thorough re potting in spring. I mean yesterday.

Mike

Mike, thanks for your prompt reply!

See pic below for the soil. The top soil feels very dry to the touch at the moment...

I'll change the soil today as you suggested! What kind of soil should I use? I was told that the Miracle-Gro Palm, Cactus, Citrus offers good drainage. Would mixing that with orchid bark mix help? This for instance (https://www.amazon.com/Sun-Bulb-50000-Special-4-Quart/dp/B00KWXTH36/ref=asc_df_B00KWXTH36/?tag=hyprod-20&linkCode=df0&hvadid=193150648923&hvpos=&hvnetw=g&hvrand=10961600745713714004&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9067609&hvtargid=pla-375566663477&psc=1)

I'll post more pictures once I take the tree out of the pot.

As per your other questions:

Have you been using tap water? Yes, at room temperature. Should I use something else?

Have you been watering so the the water comes out freely from the bottom? Ehh that's the problem. The water does not come out from the bottom. The pot only has one drainage hole in the center. I should probably drill more holes.

Can you push your fingers almost down to the retentive water level? Like beyond the root ball? I used a moisture meter -- it reads 3 on a scale from 1 to 10.

Have you been fertilizing? I use the Miracle-Gro Miracid once a month in the winter, and twice a month in the summer. Is that enough=

Can you lift the pot for weight to tell when to water? Does that soil seem to be compacted at all? The soil does seem compacted...but the pot feels almost light, and certainly not as heavy as when I water it. I honestly can't figure out if I overwatered or underwatered! The yellowing and brown tips on the leaves seems to indicate overwatering, but the soil feels almost dry

Mike did you mean a 511 soil mix change and not 911

I think the poor thing isn't getting enough/proper water. Start by sinking the whole pot- up to the rim - into a bucket of warm water; let it sit for at least 15 mnutes; pull the pot out and let it drain until no more water comes out the bottom.

I'm not an expert on soils, so I won't go there. But I do know from past experience that once the soil dries out it can take awhile to rehydrate.

C.A, that is another possibility. I was thinking that. I wonder if the roots are not getting properly hydrated either. So many possibilities. I can't wait to see the pics of the soil.

HU, if you want to know if the soil is getting properly moist, you can stick a wooden dowel in it and test that way after you have waterd it to see if there is any dry areas. Too, you could water it as you would, then lift the root mass to see if they all got a drink. Look for dry ares of roots and soil.

By any chance are you watering with water from a water softener

Hi all,

Thanks again for your continued help!

Home depot did not have supplies for a 5-1-1 soil mix the other day, so I have to order them on amazon. In the meantime, I soaked the pot as CA suggested and, lo and behold, the upper leaves started perking up within a few hours. See pic below.

Having that said, the lower leaves are possibly looking worse. Yesterday morning I noticed dark spots on many of them. Some leaves were starting to dry up, and were completely dry and curled up by this morning. It seems like the problem is progressing from the base of the trunk to the top. Some of the leaves that sit close to trunk in the upper branches are also look dry and have dark spots now. I'm not sure what to do...

Hi all, quick update.

The situation is more or less the same as yesterday: the leaves near the trunk are drying up and falling.

Not sure if this means anything, but I noticed that all of the leaves that are doing poorly have one or more tiny black spots on them. They don't look like bugs or holes--just tiny black marks. I don't see similar marks on healthy leaves. Is this some kind of disease? I see no signs of pests on the tree at the moment...

You have to understand that this plant has been under stress for awhile, so a lot of damage has been done. All that you're noting above might be from long-term lack of enough water. Leaf loss would be expected. I am glad the the good soaking revived the top-most leaves; that's promising. Citrus need a steady water supply; they are not drought tolerant. Also, I hope you can put this Lemon outside when the weather is warmer because citrus are not good indoor plants.

Good luck to you and the transplanting to better soil.

Kate

UPDATE: I repotted the lemon and noticed that there was quite a lot of salt buildup on the top soil. Maybe that explains the brown leaf tips and leaf drop.

And FYI: This is how the roots looked. They were deep but not really spread out. What do you think?

that looks good.

Steve

I asked before; but I will again... is there any chance you are watering with water from a water softener?

Hi John, no, our building doesn't have a water softener

Tap water alone is just lousy for my trees. If I were you, I would use fertilized distilled or rain water through the winter.

If you can't, then come spring, I would do a major overhaul on the mix I use, using a very porous one that allows the salts to drain through every time you water. That means rinsing out all the old mix so that my tree was bare rooted before planting it in an entirely different type. But for now, I would do a thorough flush on my trees until the water comes through for atleast a minute over a sink or in the bathtub.