It was the Arabs who first brought comfrey (symphytum officinale) to the attention of the Crusaders, who in turn transferred it to the monastic gardens of medieval Europe. At that time, the clergy were the sole keepers of academic knowledge, and thus also the medicinal sciences, and it is their influence on modern herb gardening that I would like to focus on.

Many people are familiar with the rule of thumb that says if a plant has the word officinalis in its name, it is, or was once, used for medicinal purposes. This is true but, in fact, the title officinalis (from which we derive the modern "office"), meaning a workspace or set of rooms – an apothecary’s workshop, in other words – dates from as recently as the 16th century.

Prior to this, monasteries had an armarium pigmentation, taken from the Roman usage of pigmentarii to mean pharmaceutical as well as "pigment" or make-up. This was a small area devoted to the production of herbal remedies and preventatives, and it was fuelled by the monastery gardens, which often extended to several acres, and contained plants with a multitude of uses.

Thus, comfrey was a staple of monastic gardening, and acquired the common names of "knitbone" and "healing herb", among others. The plant, which is also edible, an excellent fodder crop, green manure and fertiliser, was used in ointments and poultices to heal broken bones – the name derives from the Latin confirma, "joined together"– wounds, bruises and, as an infusion, to treat tuberculosis and dysentery. In modern times, it has been proven to contain significant amounts of B12 vitamin, plus silica and albition, substances which accelerate the replenishment of bone matter: a true example of a herbal medicine established as a medicinal herb!
Comfrey requires a nitrogen-rich soil, well dug and with a neutral pH. It will grow happily in any sunny corner of the garden, but is very difficult to eradicate, so position it carefully, or try growing it in a large, deep container.

In the 10th century, the Emperor Charlemagne ordered that certain herbs be gathered and cultivated in monastery gardens, for medicinal use. This operation was known as the Capitulare de Villes and, from this, many plants that we might otherwise not know today found their way into lay-people’s gardens, and were preserved. Of course, this link between religion and herbalism (present in many traditions other than Christianity, for the record!) leads to an inevitable conflation of practice and philosophy.

The medieval nun, Hildegard of Bingen, wrote two herbals, "Physica" and "Causa et Curae," in which she suggests that the earth produces plants in a manner similar to the functions of the human body, i.e., its "sweat" produces "useless" herbs, but the earth’s "juice" brings forth "grapevine and germinating trees." Further to this, the "useful" herbs meet humanity’s spiritual needs, while the "useless" ones reflect the "diabolical ways" of mankind, reminiscent of the antithetically clear-cut divides of Christian theology…

In truth, many of the herbs grown and used by medieval monasteries could not – and can not – be so clearly defined. The cottage garden favourite foxglove (digitalis purpurea) has been used as a cardiac tonic for the last two hundred years, and was used from the 11th to 18th century to treat dropsy, or water retention, but – of course – the plant is highly poisonous and, even in the hands of professionals, overdoses occurred and were frequently fatal.

Hildegard, who lived and worked mainly in what is now Germany, but whose Benedictine legacy lives on in modern monasteries such as that of St. Gertrude, Cottonwood, Idaho (the proprietors of an amazing herb garden based on medieval plans), also wrote effusively of savory (satureja montana / satureja hortensis), sage (salvia officinalis), thyme (thymus sp.) and parsley (petroselinum crispum). These well-known culinary herbs all possess antiseptic qualities – thyme especially so – and were used in the treatment of everything from stomach complaints to leprosy. All four are also excellent choices for a terrace or container garden, and thrive in well-drained soil under full sun. In addition, underplanting roses with parsley helps to deter blackfly; this was another reason for its presence in the monastic garden, as the older forms of rose (var. gallica officinalis) were grown for use as blood tonics and flavourings, as well as for their aesthetic appeal.

Other modern recreations of the medieval gardening paradigm – Nortion Priory, Cheshire, or the Bede’s World Physick Garden, Northumberland, linked to the writings of the 8th century monk the Venerable Bede – have worked to re-establish the system of large, open beds and areas set aside for contemplation.

Many monastery gardens featured "cloister garths", turf quadrangles sometimes planted with symbolic juniper trees, and "cemetery orchards", where the dead of the Covenant were buried, the process of their decomposition feeding the trees, while the resultant blossom and fruit enlivened the senses of the living. Usually, apples were grown in these orchards, but the close relative of the apple, the quince (cydonia oblonga) was used medicinally to treat eye diseases, fever and gout, in addition to use in the myriad of jellies, pies and jams that are still popular today.

Butterbur (petasites hybridus), a large, architectural plant that grows naturally by rivers and streams, but makes an excellent feature in a cultivated bog garden, was the first line of defence that medieval physicians and their patients had against the plague. Otherwise known as "devil’s hat" or "bog rhubarb", it was grown alongside fox’s clote (arctium lappa, better known as burdock, bardana, beggar’s buttons, burrseed, hardock, or touch-me-not, among numerous other names) for the treatment of skin diseases, lesions and ulcers, and is still used in this capacity today.

An interesting product of medieval herbalism was the doctrine of Significance, which states that, either the part of the human body a plant, nut or fruit most resembles is the part it may be used to treat, or that the disease a plant resembles is the one it will cure. Thus, walnuts are supposedly good for the brain while lungwort (pulmonaria officinalis, otherwise known as Jerusalem cowslip) is said both to resemble the human lung, and the mottled appearance of the organ in a state of affliction (the mid-green leaves are oval in shape and have blurry white spots across their surface).
Modern herbalists may still prescribe an infusion of lungwort for pulmonary complaints (and even if you don’t have a weak chest, it’s worth finding space for this delightful ground cover perennial. It laps up the shade under spreading trees beautifully.), so it seems, once again, that we have something to learn from knowledge passed down over the centuries.

All in all, much folk lore and herb magick – even the lauded ways of the cunning men and wise women – leached initially from the libraries of ancient monastic orders. In Europe and America, we have the Cistercians, Gilbertines and Benedictines to thank for a vast body of symbolism and wisdom concerning plants and, throughout the world, there are further herbal traditions rich in centuries of practice and theory. In the Buddhist Kopan Monastery, Kathmandu Valley, for example, Geshe Lama Konchog’s Stupa houses a Throne, or treasure house, containing ten two-metre high "wealth vases". Each of these contains, as a relic to the Bodhisattva, several kilograms of soil from holy sites, various gems believed to be endowed with sacred or magickal properties, and five hundred kinds of medicinal herbs. Kind of makes you think of an inter-faith relations project, doesn’t it? ;)