I work at a retail nursery and one of my customers offered me a potted Meyer Lemon tree. I don't know much about the plant, such as age or what the potting medium is, however it is about 2 feet tall in the pot. I live in Maryland in Zone 7, so I brought it inside for the winter and set it in front of a north facing window. I read that citrus like moist but not wet soil, so I have been watering it every 3-4 days with a few cups of water each time. The healthy green leaves are starting to fall off and some of the leaves are turning yellow and falling off. The plant came to me with lots of small, green fruit and fragrant blooms all over it. Now, a lot of the small fruits are yellowing, some turning black, and falling off. I have noticed some small insects that look like fruit flies flying around the plant, but they don't seem to be attacking it in any way. Anyone have any ideas on what the problem could be?

Thanks again!

Use a wooden dowel or skewer stuck all the way into the container to measure
the amount of moisture in the deeper layers (this is key). If the stick comes
out clean and dry, water. If the stick comes out damp or dark, don't water. re-test
every 2 days until the soil is dry enough to water again. A wick (synthetic fiber/string)
can also be stuffed into a drainage hole and allowed to dangle below the container to
reduce excess moisture in the bottom of the pot.

These tricks will help you limp your plant through the winter, but they won't take the
place of a properly made mix and a full re-potting next Spring/Summer.

Josh