The citronella plant is a hybrid that combines the Chinese citronella grass with the African geranium. It grows and is cared for like a geranium but has the lemon scent of the citronella. You may find this plant in garden centers and nurseries under the name mosquito plant because it repels mosquitoes like citronella candles. The citronella plant is a warm weather plant grown mostly in containers so it can be left outdoors in the summer and wintered indoors. It can be grown in the ground in gardening zones 9b through 11.
Bring the citronella plant indoors when the temperature starts to dip into the low 60s (Fahrenheit) at night. If the plant is in the ground, carefully dig it up and place it in a flower pot along with the soil it's growing in. Make sure the pot has drain holes.
Place a dried leaf and pine needle compost on top of the soil in the pot. Citronella needs a lot of nitrogen to keep them green.
Place the plant near a window where it will get six to eight hours of sun each day. If you don't have an area that will give the plant enough light, hang grow lights about a foot over the plants and turn them on until the plants get 8 hours of light per day. For example, if you get three hours of sun through a window, leave the lights on for another five hours.
Keep the citronella away from heater vents and drafty areas. Don't place them near an outside door that will opened frequently. The ideal constant temperature is between 60 and 70 degrees F.
Water when the top of the soil starts to dry out. Citronella is slightly drought tolerant and would rather be a little dry than have too much water.
Cut stems back by 4 inches with sharp pruning shears and remove the bottom leaves from the stems. Place them in a mixture of damp sand and peat moss in a separate container. Keep them moist and in indirect light until they start to grow roots. They will be ready to place outdoors in the spring with the mother plant.