Geranium Citronella

The Citronella Geranium (Pelargonium citrosum) is a tender, shrubby perennial popular for its lemon-scented, lacy green leaves and small pink/lavender flowers. Often called a "mosquito plant," it releases a citronella aroma when leaves are crushed, though it is only truly effective as a repellent when the oil is applied to the skin. 
Key Characteristics & Care:
Appearance: Features deeply lobed, ruffled, light green leaves and produces small clusters of pink or magenta flowers with deeper markings.
Scent: The leaves have a strong citrus aroma reminiscent of citronella candles when brushed or crushed.
Size: Typically grows into a bushy mound about 2 to 3 feet in height and width.
Growing Conditions: Thrives in full sun to partial shade in well-drained soil. It is drought-tolerant once established.
Hardiness: Considered a tender perennial that is hardy in zones 8-12; it is commonly grown as an annual or a container plant that is brought indoors for winter.
Usage: Ideal for patio pots, hanging baskets, and along walkways where the scent is released when passed. 

While often marketed to repel mosquitoes, the plant's presence alone is not a highly effective repellent; it works best when the leaves are rubbed on the skin or crushed.