Plant more hemp

It's far more helpful than cannabis

Photo by Esteban Lopez on Unsplash

Occasionally, I read something which really excites. My first reaction on discovering the history and super-plant properties of hemp (sometimes called industrial hemp) was to wonder why we’re not growing it everywhere?

Hemp and cannabis plants are the same species, but legally hemp only contains 0.3% or less Tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis. That particular feature is the least interesting part of this story.

Hemp is the only plant that can feed us, clothe us, house us and protect the environment. With a myriad of uses, this wonder plant can support the world on almost every level. The psychoactive element has historically made it much maligned. Does the future look any better?

The potted history of hemp

The cultivation of hemp dates back to 8,000 BC in Asia. Chinese legend refers to a mythical Emperor Shen Nung in 2800 BC, teaching his people to weave hemp into clothing because of its strength and abundance.

Once the Chinese had mastered the use of hemp in clothing, rope and medicine, it spread quickly west along existing trade routes, where the seeds and oil were used for medicine and food, other parts of the plant for sail canvas, rope, clothing, and as a building material.

In ancient Hindu religious documents, it is referred to as sacred grass, one of the five sacred plants of India.

Commercial production in Europe of rope and oakum (hemp fibre mixed with tar) became vital to support colonial and naval expansion. Whole fleets were rigged with hemp sails and ropes, which were particularly strong and salt resistant. Every ship was also smart enough to carry hemp seeds, in case they landed somewhere unknown.

It became so important that King Henry VII in 1533, decided to start fining farmers that refused to grow it. Its importance is reflected in English names which referenced hemp all over the country, including the county of Hempshire, now called Hampshire.

The founding fathers in America were also quick to use it for clothes, shoes, rope, paper and food and by 1700, US farmers were required by law to grow it as a staple crop. It’s particularly versatile, because it grows with little else than rainwater and needs no tending until it’s time to harvest.

Hemp is ruined by association

In the US in the early 1900s, the word cannabis was replaced with marijuana, in an attempt to associate the plant with the Mexican population. The 1937 US Marijuana Tax Act was deliberately designed to destroy the hemp industry by levying a tax on anyone who dealt with it commercially.

One claim made was that Andrew W. Mellon, Secretary of the Treasury at the time and the wealthiest man in America, had invested heavily in DuPont’s new synthetic fibre, nylon and wanted to provide a helping hand to guarantee its success. If it’s true, it didn’t help him much because he died later that year.

During WWII, the tax was lifted by the US government, who needed it for uniforms, canvas and rope. They even produced a documentary called Hemp for Victory, encouraging farmers to help the war effort. 400,000 hectares of hemp were planted in the Midwest and Southeast as a result.

By the 1950s, the Soviet Union had become the world’s largest producer, with a research department in Ukraine specialising in developing new varieties.

Unfortunately, clean living America decided to classify marijuana as a Schedule 1 drug alongside heroin and LSD in the 1960s with many other countries following suite as a result. Because there was no distinction made between hemp and marijuana, little further research and production was undertaken.

In 1971, the UK started to reissue cultivation licences under the Misuse of Drugs Act, allowing industrial hemp to be grown. President Obama signed the Farm Bill in 2015, allowing research institutions to start farming programmes again in the US.

Benefits to the planet

Hemp works over time when it comes to capturing carbon dioxide from the atmosphere. It’s a more effective sequester of CO2 than trees, capturing twice as much. Industrial hemp absorbs between 8-15 tonnes of CO2 per hectare, forests, typically 2-6 tonnes, depending on the type of trees and the climactic region.

Hemp is a weed which grows fast. A crop can be grown in 4 months, which makes it easy for farmers to add it to their annual rotation, while helping to regenerate the soil because of the nutrients that hemp leaves behind. It takes up relatively little space, is biodegradable and produces more pulp per acre than trees.

Very few UK farms grow hemp because of the bureaucratic nightmare of obtaining a licence. The farmer has to apply for a controlled drugs domestic licence costing £600 which is also subject to personal checks.

This out of date legislation, shows a lack of education, plus the lingering stigma by association with the THC hothouse alternative and probably fear of change. Hemp is about to have a significant impact which large scale agricultural business and government need to reflect on and support.

Margent - a hemp farm and house in Cambridgeshire

Margent is a 53 acre hemp farm which is now certified fully organic. When it changed ownership in 2016, the land had been unattended for years and was overgrown with thistle and mayweed.

Now aside from growing hemp, the field margins are a haven of wild grass and flowers, attracting birds and insects with a boundary of healthy hedges with fruit trees planted every 30 metres.

Apart from selling what they grow from the hemp fibre and oils, the Margent’s farmhouse is mainly made from Hempcrete, a mixture of hemp and lime, which was processed from their first year’s fibre crop.

A thoroughly modern material

Hempcrete, uses the woody inner part of the stem, called the shive and can be used as infill on any non-load-bearing wall and as an insulation material.

The strong, stiff fibres from the outside of the stem can be used to produce carbon-negative, bioplastic products and construction material, replacing fibreglass composites and aluminium, using far less energy to produce them.

Where?

About 70% of industrial hemp is grown in China, but Romania, once a world leader is trying to regain its former position. Germany is also increasing production but France still accounts for more than 70% of EU production, followed by the Netherlands (10%) and Austria (4%). There are only about 20 licensed UK growers currently.