When planting culinary and medicinal herbs it’s necessary to choose the location wisely. It’s so easy to overlook environmental hazards when you think a particular herb or herbs would look lovely planted along a driveway, fence or near the garage or carport. These locations have the potential to load herbs with environmental toxins such as petrol and diesel fumes from car exhausts that are absorbed by the leaves and in turn released in to infusions and other remedies as well as foods containing these herbs.
Some time ago one of my daughters asked me to look after her potted lemon balm because she was relocating. Without thinking we put the pot near the carport, a perfect location for it (or so we thought) with only the morning sun. Because the pot is very heavy that’s where it stayed being watered and fertilized regularly. Not so long ago I wanted to use lemon balm as an ingredient in an ointment I was making. My plants needed to recover from regular pruning for infusions so I thought I’d use my daughter’s plant. Before I harvested it I realized the pot was right beside the car and the leaves would have absorbed the exhaust fumes. I couldn’t believe I hadn’t thought of this when we put it there.
The solution is to move the plant to a new and suitable location, prune it back completely so new growth will be free of toxins and before using it let it grow for quite some time allowing watering and rainfall to flush any remaining toxins out of the plant tissue.
Any herbs that are established along driveways and fences beside roads or anywhere cars travel and where they are near other environmental toxins are best left where they are and used only as a garden plant. It’s much better to obtain new plants and locate them in an area of your land that is as free of toxins as possible.
Also, never collect herbs growing along the roadside or herbs planted in gardens such as those in supermarket carparks. Rosemary is one such herb that is now popularly used for landscaping and, in fact, is growing as a border along the carpark at a shopping complex in a town not too far from me.