Storage of Medicinal Herbs
Answered by: Susan Eagles
Question from: Rosemary
Posted on: July 11, 2007

I have many bulk medicinal herbs that I purchased 10 years ago, and stored in their plastic bags inside tupper ware. I don’t dare use them out of fear of what harm they could cause. Can bulk medicinal herbs become useless, toxic, or even poisonous?

Dried herbs lose their effect over time. Herbs should be stored in airtight glass jars, away from heat and light. Chemicals from plastic storage bags and containers can be absorbed into the herbs. For herbs with volatile oils, the oils in the plant are absorbed into the plastic and then lost through evaporation.

Each herb has its own unique duration of time in which it retains its properties. A rule of thumb is that leaves and flowers should be stored no longer than a year. They can be used after this time, but you will need to increase the quantity to get the medicinal effect. Roots are generally effective for a much longer time period.

Herbal parts stored in their whole form, such as unbroken leaves and flowers (or petals) and whole roots, all retain their effectiveness longer than cut or powdered herbs

You can test the effectiveness of herbs by smell, taste and appearance. The colour of the dried herb should be pretty much the same as the live plant. For example leaves bright green and flowers vividly coloured. The smell and taste should be strong.

Herbs that are properly stored will not become harmful. If they are improperly dried or stored, for example If any moisture remained in the herbs, they may contain moulds and be dangerous to use.

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