Hi, I have had my kumquat tree for about 6 months. When I bought it, it was 3-4 feet tall and healthy with lots of green leaves and fruit. Most of the fruit was close to being mature when I got it. I repotted it in an approximately 3 gallon container. I watered it regularly (about 2 times a week at first) and fertilized every few months. I kept it away from my baseboard heaters (as that dried out my last citrus tree) and in a room that got a lot of ambient light (although it wasn't directly in front of a window). Gradually since then the leaves have dried up and fallen off and many of the branches became bare. It has not grown taller since I bought it and I have reduced my watering to about once a week. I moved it upstairs, where it was placed directly in front of an east facing window. Recently, I decided to prune back the dead branches and have moved it into a room with a north facing window and added a 40 watt fluorescent bulb. The bulb is a few feet long and hung vertically parallel to the trunk of the tree. The tree is a few feet away from a window (can be somewhat cold) and I am planning on adding a second fluorescent bulb. Although many of the leaves have fallen off, the goods news is there is some fairly new growth that has bright green branches leaves. Please let me know what I can do to help this tree flourish.
I grow citrus indoors and I've lost a number of kumquat trees due to, I believe, low humidity levels. In my plant room it is around August that levels are at their lowest. You may want to check using a hygrometer. Kumquat trees appear to be finicky; mine dropped a number of seemingly healthy leaves earlier this season for some unknown reason. (Come to think of it, it may have been due to a combination of sun exposure and cold roots.) Thankfully they were replaced with a bunch of new ones. It is recommended that a tree be watered only once the medium has had a chance to dry somewhat. Guage the amount of moisture in the container by checking the top couple inches of the soil or by the weight of the container. Never water on a schedule. The tree should be fertilized at least once a month during the growing season. Generally speaking, citrus will benefit from higher levels of light. My trees are behind south facing windows and receive no additional lighting.
Interesting, I purchased a somewhat mature (3-4 feet) Kumquat and had the same thing happen. Major leaf drop for no reason, that and some of the branches died. My tree was outside in Massachusetts, actually in the ground. I was thinking that I must have damaged the roots? Frank
