A conclusion on comparing several brands of lemongrass, including Jade Bloom lemongrass.
Young Living, doTERRA, Aura Cacia, Plant Therapy, Edens Garden, Jade Bloom, Native American Nutritionals/Rocky Mountain Oils, Now, and Mountain Rose Herbs (not pictured).
All brands of lemongrass are of the variety Cymbopogon flexuosus, except for NAN/RMO, which is Cymbopogon citratus.
For this experiment, I used separate identical glass droppers to account for the varying size in droppers that came with each brand's bottle of essential oil. The petri dishes were examined at 24 hrs incubation to observe preliminary results. At 48 hrs the petri dishes were removed and images were taken. For additional explanation of methods, please check the "About Me" section.
Observations & Results.
Order from least inhibition to most (based on my personal observation and examination of the Petri dishes): NAN/RMO (top right), (from left to right) Edens Garden, Jade Bloom, Plant Therapy, Aura Cacia, (bottom left to right) MRH, Young Living, Now, and doTERRA.
Results from the original lemongrass experiment:
NAN/RMO, Now, Plant Therapy, Aura Cacia, doTERRA, Young Living, MRH, Edens Garden.
Results from the second lemongrass experiment:
NAN/RMO, Now, Edens Garden, Plant Therapy, Young Living, doTERRA, Aura Cacia, MRH.
Table 1: Analysis of results from all three experiments.
Table 2: Adjusted results based on modifying outliers.
The third lemongrass experiment includes Jade Bloom lemongrass. A friend and follower of the blog shipped me a new bottle in order to test it against the others. It appears to have performed as well as several of the other brands tested.
Less bacteria colonies grew in this experiment overall, which may be due to the sudden drop in temperatures in my region. Each brand inhibited bacterial growth, except that NAN/RMO had a bacteria colony grow on the location that the essential oil was placed, for a second time (see Part 2). However, halfway through the experiment at 24 hrs incubation, the bacteria colony was not yet present. Therefore, NAN/RMO lemongrass inhibited bacterial growth locally at 24 hrs, but not at 48 hrs. A few other observations to note are that Edens Garden lemongrass performed similarly to how it did in the second experiment, Now lemongrass performed much better than in the first two experiments (relative to the other brands), and the rest remained fairly consistent.
In combining the three experiments, the brands were ranked based on relative efficacy and totaled the scores. (See Table 1.) Those with the highest totals were consistently less effective and those with the lowest were consistently more effective. In order to account for the outliers in the experiments, specifically the results for Edens Garden in the first experiment and Now in the third, I adjusted the ranking score to what would be comparable for each brand in the remaining experiments. (See Table 2. Note: This part of the analysis may not be statistically sound, because many more experiments would have to be done in order to determine true outliers, but I believe it to be a reasonable adjustment to make in order to rank the effectiveness of each oil across the three experiments.) Mountain Rose Herbs performed consistently better than the other brands, as well as doTERRA and Young Living. Aura Cacia follows closely behind, then Plant Therapy, Edens Garden, Now, and finally NAN/RMO as least effective.
Combining the results from three separate experiments is more valuable than results from one or two. This is why studies are repeated and even a reason why the accepted scientific conclusions on one subject may change over time. Ultimately, every oil tested was found to inhibit bacterial growth in the experiments, to a greater or lesser extent. Even NAN/RMO lemongrass fully inhibited bacterial growth in the first experiment, and inhibited bacterial growth at 24 hrs incubation in the third. The fact that NAN/RMO lemongrass was a different variety than the others may be the reason for it's reduced effectiveness and/or longevity in comparison to the other brands. The analysis on the three experiments can be scrutinized and the execution of the methods debated, but the results are here for you to make your own conclusions as well. In the future, I would like to see how lesser-known brands of essential oils stack up against these popular brands.