Roots Most growers give little thought to the roots of cannabis plants beyond ensuring that they are healthy and supplied with water, nutrients, oxygen and drainage—before discarding them at harvest time. But the roots have been used in folk medicine for millennia, and contain several compounds that may be of medicinal value.
Use of cannabis roots as medicine through history
There is a long documented history of utilisation of cannabis root as medicine. The oft-cited Chinese herbal Shennong pên Ts’ao ching, dated to around 2700 BCE, mentions that cannabis root was dried and ground to form the basis of a paste used to reduce the pain caused by broken bones or surgery. It was also crushed to extract the fresh juice, or boiled to make a decoction, and in this manner used as a diuretic, as an anti-haemorrhagic to stop post-partum bleeding in childbirth (as well as other forms of bleeding), to ease difficult childbirth, and to reduce pain and swelling from bruises and scrapes.
The Roman historian Pliny the Elder wrote in his Naturalis Historia in around 79 CE that cannabis root could be boiled in water to make a preparation that relieved joint cramps, gout and acute pain; he also stated that the raw root could be applied directly to burns to reduce pain and blistering, but must be changed frequently to prevent drying-out. The Roman physician Dioscorides also attested to use of boiled cannabis root poultices to treat inflammation, gout and ‘twisted sinews’. The Greek medical writer Oribasius wrote that the ‘dry’ root could also be applied to eruptions of the skin such as subcutaneous cysts, when mixed in equal quantities with pigeon droppings—although no other source apparently makes this claim.
The English physician, William Salmon wrote in the early 18th century that cannabis root could be mixed with barley flower and applied as a poultice to treat sciatica and pelvic joint pain. From the late 18th century up to the turn of the 20th century, American physicians would recommend decoctions of hemp root to treat inflammation, incontinence and venereal disease.
Modern-day/anecdotal use of cannabis roots
Traditional use of cannabis root is known to have persisted up to at least the 1960s in Argentina, where it is used to reduce fever, dysentery, and gastric complaints and to improve overall health and well-being. There is also a hemp-root tea known as ma cha that is still consumed in Korea, although it is not clear exactly what its medicinal benefits are held to be.
Many modern-day growers, as well as dispensaries and patients in the USA, utilise preparations made from cannabis root to provide subjective relief from a range of ailments. Some home-brew cannabis root ‘tea’, usually by slowly simmering the dried, powdered root (often with cinnamon bark, anise, or other aromatics) in a crock pot for twelve hours or more before straining and drinking. If it is put back on to boil after straining, it can also be reduced down to a gummy, tarry extract that can form the basis of tinctures or liniments. Others will simmer the root in oil and water, before separating out the residual oil from the water and plant matter and using as the basis for topical medications.
Some even use the root in its dry, powdered form to make dry poultices that can help to soothe and heal burns, cuts and skin complaints such as dermatitis. There is even one report of dried, powdered root being used to ‘draw out’ the venom from a scorpion sting—this may have some validity, as fresh cannabis juice was apparently used for this purpose in ancient China.
Various dispensaries now reportedly stock preparations made from hemp and cannabis root; one of the most well-known suppliers of these products is a company known as Hemp-EaZe, which specialises in topical hemp root preparations. Their range includes body lotions, salves, lip balms, massage oil, and even a spray for household pets. They state that their products, which are blended with other medicinal oils such as comfrey, lavender, sage and burdock, are effective in treating a range of conditions including psoriasis, eczema, arthritis, joint pain and fibromyalgia.
Cannabinoids in the roots
There is evidence to suggest that cannabis roots contain some trace quantity of cannabinoids (particularly CBD), and that the concentration depends on the strain, as well as being affected to some extent by environmental factors. Apparently on this basis, there are now various outlets in the USA selling powdered, ‘activated’ cannabis root ostensibly for its high CBD concentrations. However, it appears that concentration of CBD in cannabis root is very low, and it is doubtful that it would have any medical efficacy at such levels.
A Canadian study published in 2012 analysed Finola hemp and found that the flowers contained CBDA (the acidic precursor to CBD) at an approximately 2.4% concentration, while the leaves, stems and roots contained 0.5%, 0.04% and 0.004% respectively. The various parts also contained the precursor to CBDA, a substance known as hexanoyl-CoA, in concentrations of 15.5%, 4.0%, 2.2% and 1.5% respectively. Studies into high-THC varieties are apparently not available, but it is likely that the roots would also exhibit much lower concentrations than the flowers and leaves.
Other substances of medical interest in cannabis roots
Although the roots are primarily composed of sugars and lipids, low levels of terpenes, alkaloids and various other compounds have been isolated. In 1971, it was determined that ethanol extract of hemp roots contained the terpenes friedelin, pentacyclic triterpene ketones, and epifriedelanol. Friedelin is thought to have hepatoprotective (liver-protecting) and antioxidant effects, epifriedelanol has been demonstrated to have antitumour effects, and several pentacyclic triterpene ketones are thought to cause apoptosis in cancer cells, as well as reducing inflammation, pain and bacterial infection and possessing diuretic and immunomodulatory properties.
As well as terpenoids, several alkaloids that may be of medicinal value have been identified in cannabis roots. The alkaloids piperidine and pyrrolidine have both been found in the roots, as well as in the stems, seeds, pollen and leaves; these alkaloids can be highly toxic in high doses, but in smaller doses have been found to have various medical benefits. Piperidine is used as a chemical ‘building block’ for various pharmaceuticals, particularly those involved in psychiatric medicine such as paroxetine and haloperidol; pyrrolidine is also used as a building block for a class of stimulant drugs known as racetams.
The roots of cannabis have also been noted to contain choline and atropine in small quantities. Choline is an essential dietary nutrient that is the precursor to the predominant neurotransmitter acetylcholine, and is thought to be crucial to the maintenance of healthy cell membranes. It is thought that postmenopausal women are extremely likely to be deficient in choline, meaning that hemp-root tea consumed orally could provide important benefits. Atropine is well-known as a means to dilate the pupil and relax the eye muscles; it also has bronchodilatory properties, and is used to increase heart rate during medical resuscitation.
Cannabis roots and sex determination
It appears that cannabis roots grow differently according to their gender, and that a complex set of genetic interactions determines them both. A study into hemp varieties in Russia demonstrated that if young cannabis plants were cut off above the root, processed as cuttings and then kept in an aerated nutrient solution, with all new roots cut off as soon as they appeared, 80-90% of the cuttings would develop into male plants. If the roots were allowed to regenerate, 80-90% of the cuttings would develop as females.
The researchers also treated the de-rooted cuttings with 6-benzylaminopurine, a synthetic cytokinin (plant hormones that facilitate cytokinesis, or cell division) that is known to be involved in cell division and differentiation, as well as overall growth and development. Treated cuttings developed in 80% female plants. This strongly suggests that cytokinin production in the roots plays a strong role in sex determination in cannabis.
Making sure your roots are healthy
If cultivating with a view to utilising the roots, hydroponic and aeroponic techniques are preferable as they allow for a finer degree of precision when administering nutrients, enable the grower to regularly inspect for progress and signs of ill-health, and ensure that the roots will be clean and free from soil. Plant breeders have developed specialised systems to maximise root health and growth; the best-known technique involves integrated air-pruning of roots to encourage dense growth within a specified volume.
Air-pruning of roots refers to the natural die-off of roots when exposed to low humidity and air; there are various pots and trays with perforated sides available, which enable it to occur effectively. As the roots die off, the plant continually regenerates new roots, and the root ball itself becomes thick and dense. It is preferable to air-prune rather than allow roots to hit the sides of pots and then continue to grow around the container, as this leads to twisted, strangulated roots that exhibit reduced nutrient uptake. As well as ensuring the good health of the roots themselves, air-pruning also improves the plant’s overall health and eventual yield.
Keeping roots fed with a mister or dripper system is generally advisable; some growers will switch the pumps on 2-8 times per day (with increasing frequency as the root mass increases in size), allowing the medium to dry out slightly between feeds. During the vegetative period, which of course is the period which undergoes the most extensive root growth, the roots should be directly supplied with light vegetative-stage nutrient solution and root boosting solution. Ensure that adequate airflow is provided to the outside of the pots or trays, so that the roots will be exposed to the maximum fresh air and will dry out rapidly—it is a good idea to direct a fan or fans towards the roots to boost airflow.
How to make your own cannabis root balm
Anyone lucky enough to be able to cultivate cannabis can also take advantage of the potential benefits of cannabis roots. With a little effort and perseverance, and some trial and error, it is even possible to select a variety of strains to be used alone or in combination, to make balms and salves with a range of potency and potential uses.
Typically, the roots of cannabis are dried prior to being processed into balm. Then, the dried root mass is broken up into small chunks, or ground into powder with a pestle and mortar or a blender. Once the dried root is broken down into a rough powder, it is added to a slow cooker along with oil and water and gently heated for up to 12 hours, allowing the volatile compounds (including terpenoids and potentially even cannabinoids) to dissolve in the oil. The addition of water prevents the mixture from drying out and the oil from ‘frying’ the roots; the mixture should be checked every hour or so and fresh water added if necessary.
Once the heating stage is complete, the liquid is strained off and the residual root pulp is separated out and either discarded or frozen (to be processed a second time if deemed necessary). The liquid is placed in a freezer, and after some time the water will freeze while the volatile oils will rise to the surface and can be scraped cleanly off. At this temperature, the oils will usually have a semi-solid, waxy consistency; at room temperature, they will be much more liquid, and should have a smooth, translucent appearance.
Once the oil has been separated from the ice, it can be reheated and beeswax can be added to achieve a less runny, more spreadable consistency at room temperature. Trial and error is the best way to establish the desired consistency. At this time, aromatic essential oils can be added to the mixture to improve fragrance or to enhance medicinal properties, such as bergamot for cold sores and psoriasis, chamomile for eczema, dermatitis and inflammation, neroli for scars and stretch marks, or black pepper for muscle aches, cramps and arthritis.
Potential risks of using cannabis roots
While cannabis roots no doubt possess various useful and important medicinal properties, it is important to note that in high doses it can cause hepatotoxicity, due to the presence of the alkaloids pyrrolidine and piperidine. It is also reported that the alkaloid content can irritate the stomach lining; thus, oral consumption of hemp-root tea is potentially riskier than topical application. Pyrrolidine and piperidine can also act as irritants of the skin, mucous membranes and lungs. It is unlikely that the compounds are present in high enough concentrations to present serious risk, but care should be taken to avoid prolonged or heavy use.
Certainly, hemp root extract should not be consumed in its undiluted, extract form. As a tea, light to moderate long-term usage should not present any serious risk, and as a topical, any reaction should present itself rapidly and use can be discontinued with no known long-term ill effects.
Our knowledge of the properties of cannabis root is still in its infancy, and as the industry continues to develop, it is likely that even more uses for them will be discovered.