Hemp in Spanish history: from the navy to prohibition
Hemp as a strategic crop for centuries, its disappearance in the twentieth century, and how it came to be separated in law from psychoactive cannabis.
August 13, 2026
Hemp — cáñamo in Spanish — was for centuries a crop of strategic importance in Spain: its fibre produced the rigging, ropes and canvas that kept the fleet moving, and the state's interest in supplying the navy pushed the crop into the irrigated river plains. Its disappearance in the twentieth century is explained not only by international drug control, but above all by steam, imported fibres and, later, plastics. Today industrial hemp is grown again as a regulated agricultural crop, separated from psychoactive cannabis by a single regulatory criterion: the THC content of the variety sown.
Before the early modern period
Textile use of hemp in Europe long predates the modern era and is tied to rope-making, coarse cloth and the manufacture of rag paper. For the earliest periods the surviving documentation is fragmentary and does not allow a map of cultivation across the Iberian Peninsula to be drawn.
The eighteenth and nineteenth centuries
The peak of naval hemp. Demand from the shipyards turns the fibre into an input the state takes an interest in, and consolidates districts that specialise in growing and working it.
The twentieth century
A double decline: steam shipping and imported fibres first, synthetics afterwards. In parallel, the international drug conventions bring cannabis into a control regime.
The twenty-first century
It returns as an agricultural crop with certified varieties and a maximum THC threshold, under a legal framework distinct from the one covering psychoactive cannabis.
Hemp as a strategic naval crop
Before steel cable and synthetic fibre existed, a sailing ship was, to a large extent, an object made of hemp. The rigging that held the masts, the working ropes, the mooring lines, the nets and part of the sailcloth all came from the same plant. Hemp was the reference fibre of European marine cordage for centuries, and that position explains much of its agricultural history in the peninsula.
That dependence had an obvious strategic consequence: no hemp, no fleet. A ship consumed enormous quantities of cordage and it had to be replaced often, because seawater and sun degrade plant fibre. During the eighteenth century, with the naval rebuilding effort and the maritime departments of Ferrol, Cartagena and Cádiz, supplying the fibre became a matter of state interest, and the state promoted the crop for precisely that naval reason.
In everyday speech the word then referred above all to the fibre. Cáñamo meant rope, canvas and sacking, in the same way that "linen" meant cloth. That dominant sense held as long as the crop had a clear industrial destination, and it shifted in the twentieth century, when the plant's popular name came to be attached to something else.
A terminological detail that still causes confusion
Hemp and cannabis are names for the same botanical species, Cannabis sativa L. In Spain, cáñamo has traditionally been used for the fibre and seed crop, while in ordinary language "cannabis" points to psychoactive use. In popular terms the distinction between the two is not botanical but regulatory, and it is explained further below.
The hemp districts and the textile industry
Hemp is demanding: it needs fertile soil, plenty of water and heat. That is why it was not grown evenly but concentrated in irrigated river plains. The Vega Baja del Segura, in southern Alicante, was one of the areas most identified with the fibre; there was also significant production in the plain of Granada, in the market gardens of Valencia and along riverside land in the interior. How much detail that map can be reconstructed in depends on the documentation preserved in each area, and it varies a great deal from district to district.
A whole chain of trades grew up around the crop. After the harvest came retting, that is, steeping the stalks in ponds or stretches of irrigation channel to separate the fibre from the woody part; then breaking and scutching; and finally spinning and the making of ropes, espadrilles, nets, sacks, harness and canvas. Retting was also a regular source of friction between neighbours: it clouded the water and produced foul smells, which made it a matter of dispute among those sharing an irrigation channel.
Traces of that world can still be recognised. There are Spanish place names and surnames related to the plant's name, although the precise etymology of each is disputed; there are streets named after rope-making in historic town centres; and, above all, an industrial legacy remained: in some districts the rope and net industry carried on after the crop that had created it disappeared, working with other fibres.
The twentieth century and the international conventions
The disappearance of Spanish hemp is usually put down to drug prohibition, but the economic chronology matters more. Steam navigation reduced demand for rigging; then came imported fibres such as jute, sisal and abaca; and by the middle of the century nylon and polypropylene had become widespread. A synthetic rope does not rot, needs no retting and comes out of a factory rather than a river plain. Traditional cultivation, intensive in both water and labour, was left uncompetitive against that cost structure.
In parallel, and by a different route, the international control regime was built. The drug conventions of the first half of the twentieth century progressively brought cannabis into the lists of controlled substances, and that process culminated in the 1961 Single Convention, ratified by Spain. Domestic legislation was adapted to that framework over the following decades.
The two processes are worth keeping apart, because they overlap in time without being the same thing. What happened to textile hemp in Spain was, first and foremost, economic ruin: once the crop stopped being profitable, the varieties, the trades and the technical knowledge disappeared with it, and recovering it decades later meant starting again almost from scratch. The evolution of the criminal and administrative regime for cannabis in Spain, which is the other story, is explained in detail in the guide to the legal status of cannabis.
How industrial hemp and cannabis came apart
Today's separation does not depend on what the plant looks like or on what it is called, but on two criteria: the variety sown and what the crop is for. Under the European Union's agricultural framework, only hemp varieties listed in the common catalogue are permitted, with certified seed and a THC content verifiable through administrative checks. The maximum threshold is set by EU farming rules and has been changed over time, so the figure currently in force and the way it is checked are matters for the applicable regulations and the agricultural authorities, not for an explanatory article.
| Criterion | Industrial hemp | Psychoactive cannabis |
|---|---|---|
| Species | Cannabis sativa L. | Cannabis sativa L. |
| What defines it | A certified variety from the EU catalogue and THC content below the threshold | THC content above the threshold, whatever the origin of the seed |
| Legal framework | Agricultural and industrial, with administrative checks and seed traceability | Drug control legislation and, where applicable, administrative or criminal penalties |
| Usual destination | Fibre, seed, biomass and technical uses | Consumption, outside any legal commercial circuit in Spain |
| Relation to the associations | None: it is an ordinary agricultural crop | The private associative sphere rests on case law, not on an authorisation |
What the industrial hemp framework does not mean
The existence of an agricultural regime for hemp opens no route whatsoever to growing for consumption, whether personal or collective. These are separate legal frameworks, with separate authorities and separate consequences. The criteria the courts apply on that other ground are summarised in the article on the legal limit of growing for yourself, which is not a cultivation guide either and is no substitute for a lawyer.
The revival of hemp today
Since the 2010s, hemp has been present again in Spanish agriculture as a regulated crop, with far less weight than it had when it supplied the navy and with uneven take-up from district to district. What most shapes the sector today is not agronomic but regulatory: the cultivation side is settled, while the status of some derivatives is still being argued over.
Current uses have little to do with the navy. The fibre goes into insulation and construction materials, technical composites and textiles; the woody part of the stalk is used as animal bedding and as an absorbent material; the seeds and the oil are sold as food, without that allowing any therapeutic properties to be claimed for them. The most contested chapter is extracts: the status of CBD in the European Union and in Spain remains a grey area that depends on the format of the product and how it is used, and it is examined separately in the article on the legal framework for CBD.
For anyone coming to this subject from the world of associations, the history of hemp explains one thing above all: why a single Spanish word covers both a textile crop with a long tradition and a controlled plant, and why the existence of perfectly legal hemp says nothing about the position of the associations. Those bodies came into being much later and by a different route, that of case law on shared use, as recounted in the history of cannabis associationism in Spain and on the page explaining what a cannabis club is.
Directory of associations by city
Cannasys Maps collects informational entries for Spanish cannabis associations, organised by city and with the details each body publishes about itself. The listing by territory is on the cities page.
Frequently asked questions
Are hemp and marijuana the same plant?
Botanically they belong to the same species, Cannabis sativa L. The relevant difference is legal and chemical: industrial hemp comes from certified varieties with a THC content below the threshold set in the EU agricultural framework, and it is grown for fibre, seed or biomass.
When was cannabis prohibited in Spain?
There is no single date. Cannabis was brought into the international drug control regime over the course of the twentieth century, and Spanish legislation was adapted to that framework in the decades that followed. Use in itself has never been a criminal offence in Spain, although in public it can be penalised administratively, as set out in the article on fines for cannabis use in public.
Can industrial hemp be grown in Spain?
Yes, within a specific agricultural regime, with certified varieties and administrative checks. It is an agricultural procedure managed by the authorities responsible for farming, and official information on requirements and paperwork comes from those bodies. It is not an alternative route for crops intended for consumption.
Is anything left of the traditional crop?
Of the crop itself, very little: the chain of trades tied to the fibre broke in the twentieth century and has not been rebuilt. What survives is mainly heritage — place names, water-management structures, local memory — and, in some districts, a rope and net industry that changed its raw material but kept the know-how.
