In harvesting herbs, then, the aim is to store or process sufficient quantity to last the year ahead. Whether you are a family carer, a medical herbalist harvesting for your own needs or a herbal wholesaler sourcing herbs from all over the world, you have to make an informed guess as to how much of each plant you will actually need. A wholesaler will be guided by supply, demand, price, previous sales of particular species, as well as by other factors, such as profit margins, storage space, and keeping quality. Medical herbalists will be guided by the number of patients they expect to see in the course of the year, the frequency of certain presentations and their own prescribing patterns. Someone treating their family with herbs will also need to think about common health situations they are likely to encounter over the year ahead. In all situations, working out quantities that will be needed is most definitely an art, but over the years it is possible to get a pretty good feel for what will be needed. A self-sufficient herbalist has to make a judgement about whether it is feasible to grow or gather all or part of their requirements for each herb. It does not have to be an all-or-nothing scenario. Self-sufficiency is as much an attitude and a goal as it is a definitive statement of sourcing policy.
In practice, the quantity of each herb harvested is guided by the abundance in field and hedgerow. In ‘good’ years it makes sense to harvest extra stock, to act as a buffer for leaner years. I have concluded that being self-sufficient in herbs for a medical practice is a dance within the ebb and flow of the seasons. It is helpful to cultivate an acceptance that herbs present themselves more abundantly in certain years for a reason. I have lost count of the number of times that I have waited anxiously for a herb to be ready for harvest as stocks in my dispensary dwindled. Just when I think that I will have to buy in more stock of that particular herb, I spot the first signs that it is nearly ready to harvest. I rush out to my usual gathering spots and harvest just enough of the early flowers or leaves to keep me going until the main harvest can be taken. There is nothing quite like the satisfaction of bringing in a herb just in time for a patient who needs it.
It is not always possible to get quantities right, but there is a great deal of scope among our herbal community to help each other out. We live in different areas with different climatic factors and habitats. What is abundant in one person's area may be scarce in another's. We can swap herbs or purchase each other's surplus stock. We also have the option to research and buy in high-quality, ethically sourced herbs from wholesalers when needed.
We cannot always rely on being able to source all that we need through wholesale suppliers, however. When I was first studying Western herbal medicine, my tutors often spoke of potential threats to availability of herbs due to regulatory changes and political policies. One of my main herbal tutors and inspiration for my self-sufficient practice, Barbara Howe, would often say that if ‘They’ try to take away our herbs, we need to be able to defy ‘Them’ and grow them ourselves. I remember being surprised the first time I heard her talking in this way. It seemed at odds with the image I had of her as a gentle, wise herbal elder. Images can be misleading, though, and Barbara most definitely had a fire in her belly when it came to protecting herbal medicine and the herbs that she had worked with for years. She was quite right to pass on her concerns to her students. During my time in practice I have seen just how fragile the supply chain for herbs is, and how wider political agendas can have a swift and devastating influence their availability.
At the time that I was studying Western herbal medicine, the implications of pyrrolizidine alkaloids in Comfrey and the risk of it causing veno-occlusive liver disease were first being discussed within the herbal profession. The issue was the subject of many very heated debates among students as well as among our tutors and the different professional associations. Older, more established herbalists seemed more likely to be outraged by what they saw as ill-informed meddling in the traditional practice of herbal medicine, while many newly qualified or student herbalists felt pressure to abide by new guidelines in order to safeguard their future ability to practise. Professional herbal associations differed in their approaches, some preferring to have an ongoing relationship with the regulatory bodies in order to maintain an influence and others feeling it was much better to stay outside any regulation and to fight the process. At the time, these issues became enormously divisive in the field of herbal medicine in the United Kingdom – understandable among a group of people all of whom share a deep passion for herbal medicine and patient care. Discussions about herbs containing pyrrolizidine alkaloids were made more complicated by the enormous variability in the structure of these compounds, a lack of definitive knowledge about their action on the body and differing ideas about how they are broken down. It remains a very complicated issue to this day, and more research is being carried out to increase our understanding of these biological pathways and their implications. The spotlight is now also falling on other constituents, such as arbutin, which is present in Bearberry (Arctostaphylos uva-ursi) and Damiana (Turnera diffusa), among others. Arbutin is a glycoside of hydroquinone, and some sources claim that there is a theoretical possibility that it could hydrolyse into free hydroquinone. As hydroquinone is restricted in terms of how it can be used and prescribed, some countries have taken the step of also restricting arbutincontaining herbs.
Herbs that trigger safety concerns due to potentially toxic (or psychotropic) ingredients – whether or not we feel that these concerns are justified – will inevitably become less available through wholesale channels. In fact, in the United Kingdom, the Medicines Health Care Regulatory Agency actively counsels against wholesalers stocking herbs that are under review or subject to a voluntary ban on their use. Even if the restrictions are billed as a precautionary measure while further research is carried out, there is a real risk that we will lose knowledge of how to source and work with that herb if it is removed from circulation and herbal teaching syllabuses. A period of 10–15 years when a herb is out of regular use is probably enough to significantly change the prescribing habits and knowledge of an entire generation of herbal practitioners.
Growing restricted herbs, even if we choose not to prescribe them, is a way of preserving them and staying connected to the tradition and knowledge of our ancient art. I grow several species of plants that I cannot use legally as internally prescribed medicines in my practice. These include Mandrake (Mandragora), May Apple (Podophyllum), Monkshood (Aconitum) and Foxglove (Digitalis). I have no intention of using them internally on my patients, but I continue to grow them and others out of a desire to learn about and connect with the plants themselves and to preserve traditional knowledge.
Foxglove (Digitalis purpurea)
The regulatory and advisory picture varies between different countries and as new research becomes available. Please check the situation in the country where you are practising. This may influence your choice of what you will grow in your herb garden.
As well as regulatory restrictions influencing the catalogues of herbal wholesalers, general demand does too. Wholesalers need to choose herbs that are sufficiently in demand so that they can be sold before they go out of date. This means that it does not make sense for wholesalers to stock lesser-used herbs and herbs that are out of fashion. These herbs then become difficult or impossible to find commercially. Take, for example, herbs like Culver's Root (Veronicastrum virginicum) which is also known as Black Root. This is a herb that is bitter and is excellent for clearing viscid mucus from the gut. It enlivens a tired digestive system and helps to encourage a more regular bowel habit when this has become sluggish. It is a herb that was much used in the era of my dear tutor and mentor, Edith Barlow. I started to grow it because she encouraged me to work with Culver's Root. I wanted to see what the plant looked like and get to know it. At the time, I did not investigate whether or not it was available through wholesalers – perhaps it was available at that time, but it certainly is not widely available now. It seems to have become a herb rarely used by herbal practitioners. I suppose it has fallen out of favour or has somehow been forgotten. Luckily, I have been growing and using Culver's Root for many years, and I am able to continue treating my patients with it.
Mandrake