I sprayed down my Satsuma (the other plant with the white substance) with some neem oil and have spent the last couple minutes scrubbing off the white substance. My satsuma seems to have a pretty bad case of spider mites (or some other black bug). I'll spray the lemon down with some soap and alcohol and update y'all if it improves. Thanks.

Some of the leaves now have an odd type of discoloration. They've gotten lighter with dark splotches near the edges and center of the leaf.

Some leaves have also started to aggressively curl.

A lot of things have already happened to the remaining leaves, it will just help for now do some photosynthesis and food for the plant.

Your goal now is to encourage new growth to come out to further sustain your plant. So make sure it continues to get good full sun and maintain watering. Spritz the branches and stem frequently too. I had to do that to awaken the nodes too. That is why it is better to grow them outdoors, good airflow, good light, warmth and you can freely water the plant while temperatues still allow it.

Alright, I'll do that.

Just monitor your overnight temperatures there okay..we have different growing zones, and your area may get cooler faster than we do. For sure we have different humidity levels already, ours is quite low always. You may have better levels there if you have more frequent rains.

It dropped down to 66 last night and the humidity has been sitting around 50. We haven't had any rain for a week and won't get any until a thunderstorm on Friday.

yellowing of leaves in Meyer lemon tree is usually a nitrogen defficency .

Seedhunter those temps still okay even the humidity is still okay. Our humidity here is way lower at this time like 45% to 20%. 66F is comfortable for the plant to encourage leafing, as long as there is some sun and later on full sun.

Citrus trees need a lot of nitrogen and I give my citrus and stone fruit trees starting in the spring 1 cup of Epsom salt once a year citrus fertilizer as stated on the package and 6 cup's of sulfate of aluminum starting in January or as soon as the ground can be worked then in March and the last time in August every year I have wonderful luck with my trees all of the above will help with the yellowing of the leaves and make a healthy and happy tree and good and sweet fruit I hope this will help you all that grow fruit and ctitrus

As I misted my lemon tree I noticed that there were many strands of web connecting around the entire plant. At this point I'm pretty sure that at least one of the problems is spider mites. I sprayed the tree down with neem oil yesterday, but a significant amount of webs have come back. How would I go about managing spider mites?

Neem treatment should do it, good job.