Hemp
Cannabis sativa
Botanical family: Cannabaceae
Cannabis sativa, an annual Cannabaceae grown for its fibre, its seeds and, today, eco-construction (lime hempcrete, hemp wool and insulation boards). AGRICULTURAL hemp is a regulated crop: only certified seed of varieties listed in the EU common catalogue (116 in 2024), with a THC content of at most 0.3%, is authorised. France is Europe's leading producer, with more than 60% of the Union's production. Sources: European Commission, “Hemp”; Arrêté du 30 décembre 2021 portant application de l'article R. 5132-86 du code de la santé publique.
Full sun
Deep, rich and well-drained; dislikes waterlogging and compaction
Regular while establishing, then frugal thanks to its taproot
Frost-tender annual: sown after the last frosts (April-May)
An annual killed by frost in your zone
Dioecious and wind-pollinated
Needs a male plant near the female plants
Role in permaculture
A fast-growing field crop (up to 3-4 m in a few months) that smothers weeds and needs no pesticides at all. Its taproot is reputed to loosen the soil deep down: an excellent preceding crop (before wheat, for instance) and a 'cleaning' plant in the rotation. Frugal, it stores a lot of carbon and yields a huge, almost fully usable biomass, fibre, hurds (mulch, animal bedding, hempcrete and insulation) and nourishing seeds. One of the most versatile plants of the food garden and of eco-construction.
Companions
No companion planting is documented for this plant: no recommended neighbour, no neighbour to avoid.
Seasons & availability
A tall annual field crop sown once the soil has warmed, to around 10 °C, from mid-April to mid-May in an oceanic climate, and growing at great speed: for textile fibre it is cut as flowering begins, around mid-August; seed, the hempseed, and straw are harvested in August and September. Dried, the seed then keeps.
Available: January, February, March, April, May, June, July, August, September, October, November, December.
Guidance for the oceanic / temperate climate; it may vary with your region, altitude, exposure and growing method.
Sources
- Chambre d'agriculture de Normandie, « La culture du chanvre » (normandie.chambres-agriculture.fr/sinformer/rechercher-innover/bioeconomie/les-filieres-de-la-bioeconomie/le-chanvre/la-culture-du-chanvre)
- Planète Chanvre, « Le chanvre, sa culture » (planetechanvre.com/le-chanvre-sa-culture/)
- Plants For A Future, « Cannabis sativa » (pfaf.org/user/Plant.aspx?LatinName=Cannabis+sativa)
Nutritional & medicinal properties
For educational purposes. Not a substitute for medical advice. Effects depend on the form, the dose and personal context.
Precautions & contraindications
A complementary food within a varied diet, not a remedy. Hemp oil oxidises quickly: keep it cool, away from light, and do not heat it (it is not made for frying). As with any oilseed, an individual allergy remains possible.
Species & varieties
The best-known species and varieties in France.
Common varieties
Keep in mind
Do not confuse agricultural hemp (Cannabis sativa below 0.3% THC, non-narcotic) with recreational or medical cannabis, which is rich in THC and strictly regulated. Growing it is not a simple garden sowing: it is reserved for declared farmers, using certified seed of an authorised variety. CBD (cannabidiol) from hemp is legal in France (Conseil d'État ruling of 29 December 2022), but it is NOT a medicine: no health claim is permitted and its use is a matter for professional advice, this site attributes no therapeutic virtue to it.
A note on rigour: many companion pairings are gardening folklore; this note sums up what the sources say, where there are any.
Key takeaways
- • Prefers full sun exposure.
- • Ideal soil: deep, rich and well-drained; dislikes waterlogging and compaction.