There are a great many variables that need to be considered in sourcing herbs, and this brief review is by no means a comprehensive list of all the quality considerations that suppliers have to deal with. I honestly think that our herbal wholesalers are doing a heroic job in trying to navigate an increasingly complicated regulatory environment while maintaining a reasonable catalogue of herb species and trying to stay economically viable at the same time. I do not envy their challenges and the pressures they are under. I am very grateful for their efforts to provide good-quality herbal medicines, and I appreciate the option of being able to supplement my dispensary with bought-in stock when needed.
Wholesalers may be doing a great job, but if we grow or gather our own herbs, we can be much more actively involved in preserving quality at all stages of the process, from growing to medicine making. The medicinal potency of herbs varies according to the way that they have been grown, the soil type and aspect of the growing site, the season and the way that they have been harvested, handled, and stored. A huge number of factors can have an impact on the final quality of the batch. In growing our own, we can have a close relationship with the crop, and we can respond to changing circumstances in order to safeguard quality. Just as a home-grown carrot is always going to taste better than a carrot produced in a large-scale horticultural operation, so carefully produced home-grown herbs will seem more vibrant and will keep longer than mass-produced bought-in dried herbs.
My study of herbs has been lifelong so far and shows no sign of abating. I know that I am not unusual in this. It seems as though one lifetime is not enough to fit in all of the study and experiential learning that we are drawn to. We come across herbs with which we are not yet familiar, and it is only natural to want to understand how they can help people. As we research herbal properties, we start to discover that there are differences in therapeutic properties between similar species of the same genus – the Echinaceas, for example. We find it fascinating to learn how different plant parts within a particular species provide different degrees of therapeutic actions. We study various extraction techniques and see how they can change or enhance the therapeutic properties of the herbs that we are working with. We may build up a library of studies that provide evidence for the way that herbs work, or a spreadsheet cross-referencing various sources about herbal actions. There is nothing wrong in this – in fact, it is a great way to learn. I am an unashamed herb nerd. With all of this learning, though, whether through formal study or by experience, we can become so focused on the properties and actions of each herbal species that we may start to assume that all batches of a particular herbal species will act in exactly the same way. The stark reality is that not all batches of the same herb are equal. Herbs are naturally variable products.
There is quite a difference visually between the different batches of dried Calendula flowers according to their age and source. On the left are this year's flowers, and you can see that year-old home-grown flowers (middle) still have a superior colour and appearance compared to the current year's bought-in stock (right).
I lose count of the number of times that people have told me that they had tried a certain herb for a particular symptom, but it made no difference. Whenever I hear that, I do not automatically assume that the herb was inappropriate for that person. Instead, I wonder about the quality of the herb and the form in which it was taken. When I was first a Western herbal medicine student, I tried various courses of herbal self-medication for symptoms that I experienced. Looking back on my attempts now, I can see how I rather missed the point, since I focused totally on symptoms rather than understanding why those symptoms were arising. Nevertheless, it was a very valuable learning experience to take herbs and to feel their effects first-hand in my body. On one occasion, I had decided to take Dandelion (Taraxacum officinale) leaf for its diuretic effects, because I had some water retention. In those days, I was right at the beginning of my herbal course, and I had only just started to build up a home dispensary. I did not have any Dandelion leaf to hand, so I bought some pills from my favourite independent health-food shop. I know the folk who run this shop, and I am aware of how carefully they source their products. The product I bought was of excellent quality. I noticed an immediate effect and continued to take the pills until the pack finished. When they did run out, I was nowhere near my favourite shop, and so found myself buying a replacement pack from a large high-street health chain. After a few days I noticed that the Dandelion leaf seemed to have stopped working. Either there was too little Dandelion leaf in the formulation, or the Dandelion leaf that was used was of much lower quality than the one I had been taking so far. It was a real eye-opener. I had assumed that all Dandelion leaf was Dandelion leaf.
Aside from different amounts of a herb being present in a prepared formulation, why might batches of herbs vary in quality? All plants begin to deteriorate once they are harvested, no matter whether you are harvesting a tonne or just two or three plants. The speed of that deterioration can vary from almost imperceptible in the case of roots to very rapid in the case of flowers. If we are to preserve maximum quality in our herbal medicines, we need to understand how to slow that process down. The deterioration, or potential deterioration, is caused by various factors that can come into play during different stages of harvesting and processing. If we are aware of the potential for herbs to deteriorate at each stage, we can take steps to avoid this deterioration, or at least to minimize it.
It is a fact of life that large-scale growing and harvesting means that each crop has to be treated more as a whole than as a collection of individual plants. Once harvested, the plant material is transported from the field to the processing area. Whether or not the operation is mechanized, dealing with increased volumes means that it is more difficult to make fine-tuned adjustments for different parts of the harvest. There is consequently a greater risk of the herbs deteriorating in quality. It is, of course, perfectly possible for large-scale operations to incorporate management practices that preserve maximum quality in the harvested crop, and I am sure there are conscientious growers who do this skilfully. Equally, I am sure there are many growers who do not.
Take temporary storage following harvest, for example. If freshly harvested or gathered herbs are piled up in crates or in a trailer, there is a risk that the lower layers will become compressed and will start to heat up through natural biological degradation. This process takes place alarmingly quickly, especially on a hot day. You do not want to include herbs that have begun to turn into compost in your medicine. Once the herbs get back to the processing area, there are many other factors that can result in changes to their quality. These include the temperature used to dry them, their exposure (or not) to light, the amount of cyclical rehydration they experience during the drying process, their vulnerability to insects and fungi, the amount they are cut, whether they are handled once wilted, and much, much more. These factors and how to avoid them impacting on the quality of the herbs that we are growing or gathering are discussed in detail in Part Two.
When we grow or gather our own herbs, there is so much that we can do to improve the end quality of the medicine that we produce. We can make sure that at each stage of the process the herbs are treated with knowledge, care, and respect. First, we can harvest the herbs at the optimal stage of growth, on a day when the weather is suitable. We can ensure that they are not piled up too deeply or for too long after gathering, instead being transported quickly to the processing area before decomposition starts to take place. We can avoid excessive handling of the plant material so that bruising and consequent fermentation do not happen. We can choose to dry our herbs as uncut as possible, to avoid the loss of medicinal compounds. We can store them in the dark in a cool place. There are a great many stages in the process between harvesting a herb and processing it. If you contemplate the potential for loss in quality at each stage, you can see that there is an equal and opposite potential for preservation of quality at each one. All of these add up to create a significant difference in the end product.
If you have any doubt about the effects of handling fresh plants after harvest, think about the efforts that farmers go to in order to maximize the quality of their