Can you give us some examples of different soil types or minerals in the soil can affect the characteristics of essential oils?

Sure.  With essential oils, Basil is one example of different minerals in the soil leading to different characteristics or chemotypes in the plant or oil.  If Basil is grown in a soil that is high in nitrogen, that Basil essential oil is known as Basil mentha chavacol. Whereas the oil from the very same Basil plant grown in soil high in potassium, is known as Basil linalool essential oil. Again, these are the same plant but show up as different chemotypes depending on what minerals are high in the soil.

Another example is Thyme oil.  Usually the Thyme plant is grown in a higher Nitrogen soil and will end up being Thyme thymol type. The same Thyme plant grown in a higher Potassium soil will be Thyme linalool type.  And while these different types have some similarities, they also have some differences in what they work best for.

Rosemary, and Lavender also follow the same pattern, but there are oils with smaller differences, for example, Fennel oil.  With Sweet Fennel and Bitter Fennel, the difference with these two oils are ever so slight, when compared to the Basil or Thyme, but we do see the contribution of Nitrogen pushing and giving rise to the Bitter Fennel and the Potassium pushing and giving rise to the Sweet Fennel types.

We need to understand the chemotypes, or the ratio of compounds within an essential oil, in order to get the best oil for the job at hand.  This differences in the chemotypes is especially important when you’re using oils for specific purposes in clinical settings, and to a somewhat lesser extent, also in non-clinical or “real-life” applications.