Answer: Maybe

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

Summary of Scientific Research 

Thymus citriodorus (commonly known as lemon thyme) is another common natural mosquito repellant option thrown around as a folk remedy. As it stands, this specific subspecies has not received much (if any) any scientific attention in the form of field or laboratory studies. However, it is possible that its attribution of effectiveness derives from its citrus-like smell, drawing correlations to other sharp smelling natural deterrents.

Regular thyme (scientifically known as Thymus vulgaris) has received some scientific focus, however, with room for crossover conclusions between the two relates plant species. For example, a 2011 survey study found that topically applied thyme compounds were between 91.7% and 97.3% effective at fending off one mosquito species for around 80 minutes. The same study also found a thyme-based essential oil to be 100% effective at deterring a specific mosquito species for up to 135 minutes in a laboratory test (1).

Safety testing as part of the same 2011 survey study found thyme to be among the safer plant-based deterrent methods with a 2% safe concentration. Even so, the study highlighted that the same photosensitive compounds in this plant that likely deter mosquitoes may also cause skin irritation when exposed to sunlight (1).

Our Thoughts 

Broadly speaking, thyme’s ability to deter mosquitoes is well-documented, as has its overall safety for use in this capacity. That being said, it is unclear if these same properties exist within the lemon thyme subspecies such that these standard thyme testing would be practically applicable. While the results of this tests are promising, they should not be taken as definitive proof that lemon thyme will perform in a comparable manner. Anecdotal results to this end should be taken with a grain of salt, accordingly. 

Lemon Thyme Forms and Where to Get it

  • Lemon thyme plants – Should you want to undertake your own at-home testing with lemon thyme, you can grow it from scratch. This calls for procuring seeds online and planting them in sharply drained soil that contains an appropriate mix of lime. Full sun is ideal for rapid growth with this plant, as is a fair amount of watering (until roots are established, at which point rainfall will suffice). Leaves from this plant can be harvested as soon as they appear (2).
  • Essential oils – As scientifically indicated, lemon thyme oil-based mosquito deterrent solutions may hold the most potential for effectiveness. This oil can be made at home using the plant’s leaves or it can be procured in concentrate form online.

Sources

1 – Marta Ferreira Maia and Sarah J Moore. Plant-based insect repellents: a review of their efficacy, development and testing. Published online 2011 Mar 15. doi: 10.1186/1475-2875-10-S1-S11

2 – Bonnie Plants. Lemon Thyme.

Other Plants & Herbs as Mosquito Repellents

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