Hello everybody, and welcome to my first ever citrus question! I am very new, so please, go easy on an idiot. I have 4 trees-one dwarf meyer lemon, one dwarf pink lemon, one dwarf calamondin, and another meyer that may or may not be dwarfed. I have a rather small two bedroom apartment, and I have recently brought the calamondin, dwarf meyer, and pink lemon in from sitting on the porch all summer. My second meyer I purchased about three weeks ago from Lowe's, and it has only been inside. I am in Oklahoma, and the weather here can be nutty, so I figured I would keep them inside for the duration of the fall and winter, even though it has still been warm most days. Get to the point, man! all right. First question-my newest meyer is sitting in the living room facing a large window. It has two large lemons on it, with about twenty smaller ones growing. It is under a vent, but I haven't had the air on at all. I mist it two or three times daily, and water when the soil is dry. It has been steadily been dropping leaves since I got it, not an incredible amount, but enough to worry me. It dropped about five today, for example. It has many bright green leaves on it, and the leaves it is dropping are green and the stems stay on the tree. I have read that cold soil can cause the roots to go dormant. The soil does feel cold, but I have not inserted a thermometer to get the exact temp because I don't have one. If cold soil is the problem, how would an apartment dweller heat the soil? warm water? Second question-I have the calamondin and pink lemon in a room with a grow light. I leave the grow light on during the day and they are in a dark room at night. The pink lemon is dropping leaves like crazy, and recently one flower bloomed which had a weird scent and fell apart after one day of blooming. The calamondin has tons of fruit, drops about one leaf a week, and is actually growing new leaves. What is the deal here? These two plants get no natural sunlight right now, just one 60 watt grow light hanging over them. My other meyer, the true dwarf, sits in front of a small window and gets a decent amount of light. I ordered it about three months ago, repotted it, and it has shown no new growth until about three days ago, with tiny new leaves sprouting on a few branches. However, this tree has never lost a single leaf, even in the harsh Oklahoma winds. I don't really have a question about that one, I just figured I would talk about him too. Wow, this is the longest thing I have written since grade school. Any help would be appreciated, and thank you for slogging through this dissertation.
Get a soil thermometer and a water proof heating mat. On the trees that are dropping a lot of leaves, called WLD (winter leaf drop), set the tree on the heat mat and keep the soil at least 64F (70F is better). 55 degrees Fahrenheit is absolute zero for citrus roots. - Millet
Thanks very much for your response. I have a question, though-will using a heating pad heat up the soil too fast and cause the plant to go into shock? Or is that a ridiculous thought?
Not a ridiculous thought, but no the tree will not go into shock. The practice is very common with indoor citrus growers, and is one of the main ways growers avoid winter leaf drop. What is actually happening to the tree, is when a person sets the tree in front of a southern window in direct sunlight, the leaf surface can easily heat up to temperatures near or above 100F. The root system is usually on the floor not in sun light and is at a much lower temperature, (at or near 55F). Therefore, cannot supply the needed water to the leaves to cool their surfaces. So the tree starts to abscise its leaves, in an effort to get into balance with root system. Anyway a temperature of 64 - 70F is not a very high temperature to cause any type of shock. Citrus roots are active up to a temperature of 95F. Above 95F citrus roots again slow down they activity.- Millet
That is actually very interesting. How did you learn all this? The tree with the worst leaf drop is the dwarf pink lemon, which is in a dark room with about 7 hours of grow light daily. My grow light is simply one 60 watt light. Is this good enough?
