Rhubarb
Rheum ×hybridum
Botanical family: Polygonaceae
A perennial polygonaceae (Rheum rhabarbarum), native to temperate Asia and grown in Europe since the Middle Ages. Harvest from April to July by pulling the stalks and twisting them at the base. Stop in late June or early July to let the plant rebuild its reserves; oxalic acid builds up mostly in the leaves, which are not eaten (RHS).
Sun to partial shade
Deep, rich, cool
Regular (dislikes prolonged drought)
Very hardy (-25 °C)
Overwinters in your zone
Role in permaculture
A very robust perennial, to be placed in a shaded edge or a corner of the vegetable garden. Lives 10 to 15 years, sometimes more. Divide the clump every 5-6 years in autumn to keep it vigorous. The leaves, not edible, can serve as mulch or a repellent maceration, with no proven miracle.
Good companions
Poor companions
Allelopathy, reputed or observed: may slow some neighbours
Competition (water, light, roots)
Insects attracted or useful
Known pests & diseases
Pests and diseases that commonly affect this plant, tap to learn how to recognise and manage them.
Seasons & availability
Stems pulled from April to July, and from March under a forcing pot; you stop in late June or early July so as not to weaken the plant. Oxalic acid builds up mainly in the leaves, which are not eaten.
Available: March, April, May, June, July.
Guidance for the oceanic / temperate climate; it may vary with your region, altitude, exposure and growing method.
Sources
- RHS, « How to Grow Rhubarb » (rhs.org.uk/vegetables/rhubarb/grow-your-own)
- Interfel, « Rhubarbe : Présentation, disponibilité, conservation » (lesfruitsetlegumesfrais.com/fruits-legumes/autres-fruits/rhubarbe)
Nutritional & medicinal properties
For educational purposes. Not a substitute for medical advice. Effects depend on the form, the dose and personal context.
Precautions & contraindications
The leaves (blade) are toxic and are never eaten: they concentrate oxalic acid. The petioles contain too little to be toxic but remain acid: rhubarb is among the oxalate-rich foods to eat in moderation when prone to urinary stones. Cooking and good hydration are recommended, and in case of doubt it's better to seek medical advice. Sources: RHS, “How to Grow Rhubarb”; Association française d'urologie, “Règles diététiques et calculs urinaires” (patient information sheet, 2024).
Species & varieties
The best-known species and varieties in France.
Common varieties
Voices of peoples
Paraphrases attributed to their documented sources. Never an invented quote.
Chinese materia medica attributed to Shennong, as fixed in the Shennong bencaojing; the nickname 'the General' belongs to the tradition of the commentators, attributed to the physician Li Dangzhi. · China, Shennong bencaojing, a Han-era compilation (1st–2nd century); the nickname 'the General' relates to the Jin era and later centuries.
The Shennong bencaojing places rhubarb, dahuang 大黄, 'great yellow', after its large yellow root, in the 'inferior' class (xiapin 下品), that of substances with a strong, even toxic action: here a powerful purgative. This ancient classification is the attested fact, and it testifies to a purgative use recognised very early. Later tradition nicknames it 'the General' (jiangjun 将军), an image of its force that 'breaks through blockages'; this nickname, reported by the commentators and attributed to the physician Li Dangzhi, is later than the classic itself and cannot be dated to the Han.
Shennong bencaojing 神農本草經 (compilation d'époque Han, Ier–IIe s.), classe inférieure (下品) ; surnom jiangjun 将军 transmis par la tradition des commentaires (Tao Hongjing), attribué à Li Dangzhi ; Wikipédia, article « Shennong Bencaojing » (rhubarbe en classe inférieure).
The ancient classification attests the early recognition of a purgative use, not a dosage recommendation: no therapeutic effect is presented here as an established fact. The nickname 'the General' is a later commentarial ornament, distinct from the classic and not to be tied to the Han. The work and the author of the nickname are named precisely, without essentialising an undifferentiated 'Chinese medicine'.
Key takeaways
- • Prefers sun to partial shade exposure.
- • Ideal soil: deep, rich, cool.
- • Classic companion: Bean.
- • Keep away from: Cucurbits (competition).