As a hybrid with characteristics of both citronella grass and a scented African geranium, the mosquito plant (Citrosa Geranium) is often advertised for its amazing ability to repel mosquitoes. According to studies conducted by Arthur Tucker, Ph.D., from Delaware State College, it has no effect on mosquitoes in its natural state, but may provide some benefits if leaves are crushed and applied to the skin. As an ornamental plant, the mosquito plant produces attractive foliage, delicate lavender-colored blooms and releases citronella fragrance when leaves are disturbed. It retains the growing habits of scented geraniums.
Plant mosquito plants in pots or containers filled with a mixture of equal parts potting soil, peat moss and vermiculite. Plant nursery-grown plants to the original soil level, filling in around the roots with fresh soil. Firm down to secure the plant.
Water thoroughly until water runs clear from the bottom of the pot.
Place in partial to full sun. Although mosquito plants thrive in full sun, introduce them gradually to avoid damage to tender foliage. Set the plant in a partially shaded area increasing exposure to full sun each day for a week or more to acclimate the plant.
Water when soil dries and apply water-soluble fertilizer on a 14-day schedule during periods of active growth. Some prefer to apply a weakened solution mixed to one-quarter strength with each watering.
Pinch out center leaves to encourage dense compact growth. Scented geranium benefits from regular pinching, particularly early in the season, as growth spurts tend to shoot up quickly. If plants continue to grow tall and spindly, move to an area that receives more light.
Move plants inside in early fall before the danger of frost. Cut back to one-third the height and grow inside as a houseplant. Return scented geraniums outside in the spring when all danger of frost has passed.