Commonly found in most homes and gardens, geraniums are known to repel cabbage worms, leafhoppers and red spider mites. However, a special variety of geranium known as the citronella geranium or mosquito plant has been known to repel mosquitoes. This plant contains citronella oil, the same oil that is contained in citronella candles, that can be released when the leaves are rubbed or crushed.