Avoid feeding your plants during the shortest days of the year-November, December and January. With the reduced number of hours of light each day, and the reduced quality of that light, plants are not growing as fast; consequently they do not need supplemental fertilizer.

Try to provide more humidity to your plants. Their skin, just like ours, gets very dry in the winter. A tray of pebbles and water under the plant works well - just be sure that the pot sits on the pebbles and not in the water. Clumping your plants together also helps, as well as misting them with water [1].

Most indoor plants prefer a moderate temperature, around 65 - 70 degrees with a 5 - 10 degree drop during the night. However, avoid placing your plants where they will get a draft, such as near the heat vents or by an outside door.

And finally, check your plants often for signs of the presence of insects such as a sticky residue, dropping or yellowing leaves [2], and general loss of vigor. A good bath using tepid water in the kitchen sink often washes away the insects, in addition to removing the build-up of dust on the leaves, and excess minerals on the soil surface.