Flossflowers or Ageratum emits a smell which mosquitos find particularly offensive. It secretes coumarin, which is widely used in commercial mosquito repellent. Ageratum is a perenial plant which reaches heights of 8-18” & has blue flowers, although there are varieties with pink, white & violet blooms. This plant will thrive in full or part sun & doesn't require rich soil. Good in rock gardens.Leaves can be crushed to increase odor, its not advisable to rub directly on the skin.