Answer: No

We looked at the hard evidence to see if floss flower or its derivatives were effective as a natural mosquito repellent and/or mosquito killer.

Summary of Scientific Research 

As it stands, few (if any) professional researchers have put little time into studying how effective Ageratum houstonianum (better known as floss flower) is when it comes to dissuading mosquitos from hunting in a certain area. The majority of research surrounding this annual flower has surrounded the presence of pyrrolizidine alkaloids in its blooms. These compounds are toxic to grazing animals, leading to liver damage (1,2).

Floss flowers do contain a compound called coumarin, also. While this compound is found in some insecticides, no research has been completed to demonstrate that the concentration in floss flowers is enough to impact mosquitoes through dispersion.

Our Thoughts 

While a variety of anecdotal sources ascribe mosquito-blocking properties to the floss flower, none of them back up the claim with substantial evidence. So, as far as practical value is concerned, floss flowers have little to offer. 

But when it comes to aesthetic value, floss flowers still maintain a vibrant presence that is ideal for any ornamental floral setting.  With pink, white, and violet blooms readily available, these flowers certainly can be used for decorative purposes.

Floss Flower Forms and Where to Get it

  • Floss Flower plants – Even without any well-understood mosquito-blocking properties, floss flowers can still make a worthwhile addition to most home gardens. These flowers do not require rich soil by any means, and can thrive when allowed a moderate amount of water and a full serving of sunlight. Experienced gardeners even recommend planting these in rock gardens, where their beauty can really shine through.
  • Essential oils – Though a process for breaking down and concentrating floss flower exists, its practicality is questionable given the lack of substantial evidence to back up its use as a dermal mosquito repellant. Due to a lack of formal research on the topic, it is advised that those looking for a natural mosquito repellant not apply any concentration of floss flower oil on their skin.


1 – Wiedenfeld H1, Andrade-Cetto A. Pyrrolizidine alkaloids from Ageratum houstonianum Mill. Phytochemistry. 2001 Aug. 57(8):1269-71.

2 – Noa, M., Sanchez, L.M., Durand, R., “Ageratum houstonianum toxicosis in Zebu cattle”, Veterinary and human toxicology, 2004, vol.46, no4, pp.193-195.

Other Plants & Herbs as Mosquito Repellents

Checkout our analysis of other plants & herbs as natural mosquito repellents: