The citronella plant, also known as the mosquito plant, can be grown indoors or outdoors. It should be taken inside before the first frost in areas with a winter climate. Citronella can tolerate partial shade, but ideally it should get at least six hours of sunlight every day, whether from a windowsill or outdoors.
As long as it is well-draining, citronella plants can tolerate most soils. About.com recommends using a soil that is not too rich, as rich soil can decrease the plant's citrus scent. Scented geraniums like citronella are tolerant to drought and should not sit in wet soil for too long. The plant needs watering when the soil feels dry an inch below the surface. If the leaves turn yellow or brown and fall off, the plant is not receiving enough water.
During the winter, citronella does not require fertilizer. Potted citronella plants require more fertilizer than citronella in the ground. Feed potted citronella a balanced fertilizer at half of the label's recommended dilution. This can be done in the spring and summer, once a month, or as needed according to visual assumptions. For fuller, bushier plants, try pruning and pinching them on occasion. The spring months are the best for pruning.