I purchased a Meyer lemon tree last June. While outside, the tree flourished. I live in zone 5, so I brought the tree inside this October. It had since been dropping leaves at a steady rate; it finally shed all its leaves this week, including perfectly healthy green leaves. I am left with a few randomly sized green lemons. I purchased two grow lights to supplement its requirements, have a humidifier (in addition to misting the plant daily manually), and use the same fertilizer (Jobe's organic) that I used while the tree was outside. The tree is only given water when the soil dries to two inches in depth. I also recently purchased a root warmer hoping that would bring it back to life; this far it has not. Thank you in advance.
Welcome to the forums. When did you introduce the artificial lighting? The current location appears to be very dark, with little natural light. The tree may have slowly starved if it spent a long time there. I'm guessing that lights were then added to stem the leaf drop. However if the temperature of the soil was at 13C/55F or close to it, the roots would have been dormant thus resulting in further leaf drop. Perhaps that's when the root warmer was introduced. Of course this is all speculation so you'll have to corroborate. At this point I would: Remove all the fruit; Reduce watering to a minimum, just enough to keep the tree alive; Refrain from feeding the plant until the appearance of new growth; Monitor, if possible, the soil temperature with a thermometer (perhaps an old meat thermometer). I'm not convinced higher humidity is required but it wouldn't hurt. Additional misting would have little effect. Lastly, what is the temperature in the room? I'm thinking if it's cold enough it could be used to your benefit.
I have had the lights setup before it was moved inside. I have a similar setup for a lime bush, and its flourishing. The root warmer has a thermometer, I will crank that up and remove the fruit as well. Thanks for the info!
It's curious, isn't it? Two trees share the same environment and one drops its leaves. Do you have a protected but unheated location outside, like a garage, where the tree can overwinter in darkness? I'm thinking of allowing the tree to go dormant in the cold until the weather warms up.
