Turnip
Brassica rapa subsp. rapa
Botanical family: Brassicaceae
A cultivar of Brassica rapa, present in Europe since antiquity. Staggered sowings March-April then August-September for spring and autumn harvest. Sensitive to flea beetles at the young stage, cover with an insect-proof mesh for the first few weeks. Harvested young, the turnip stays tender and sweet; too ripe, it turns pungent and fibrous.
Sun to partial shade
Light, cool, humus-rich
Regular (hates drought)
Hardy (winter varieties)
Overwinters in your zone
Role in permaculture
A fast-growing root brassica (5 to 8 weeks): ideal as an intercrop between two longer crops, or in succession after peas to use the fixed nitrogen.
Good companions
Trap plants (variable effect, need watching)
Aromatic: scent said to confuse pests
Traditional companion planting (benefit not demonstrated)
Poor companions
Same family: shared diseases and pests
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
Spring and autumn turnips; large storage turnips through the winter.
Available: January, February, March, April, May, June, September, October, November, December.
Guidance for the oceanic / temperate climate; it may vary with your region, altitude, exposure and growing method.
Sources
- RHS, « How to Grow Turnips » (rhs.org.uk/vegetables/turnips/grow-your-own)
- La Ferme de Sainte Marthe, « Réussir la culture du navet » (fermedesaintemarthe.com/en/blogs/comment-reussir-la-culture-de/reussir-la-culture-du-navet)
Nutritional & medicinal properties
For educational purposes. Not a substitute for medical advice. Effects depend on the form, the dose and personal context.
Precautions & contraindications
Like the other Brassicaceae, the turnip contains glucosinolates whose breakdown products can, in large quantity and especially raw, reduce the bioavailability of iodine and hinder thyroid function (a so-called goitrogenic effect); cooking attenuates part of it. A normal, varied consumption poses no difficulty, but it's better to stay cautious in case of a known thyroid disorder and seek medical advice. Harvested young and cooked, the turnip stays tender and more digestible; too ripe, it becomes fibrous and stronger in taste. On the effect of dietary goitrogens and the bioavailability of iodine: EFSA, Scientific Opinion on Dietary Reference Values for iodine (2014).
Family behaviour: Brassicaceae
In general, Brassicaceae produce glucosinolates, sulphur compounds with a mild biocidal effect on the soil (a biofumigant effect, sometimes sought between two sensitive crops). Members of the cabbage and mustard family, they are prone to the cabbage white and clubroot.
Understanding families means learning one rule per family rather than every pairing one by one. Learn more →
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.
Pliny the Elder, reporting a votive custom of the Greeks at Delphi · Sanctuary of Apollo at Delphi; custom reported in the 1st century AD
According to Pliny the Elder, the temple of Apollo at Delphi kept a turnip fashioned in lead, dedicated as an offering. In the same notice, the radish was figured in gold and the beet in silver: to the turnip, humble and nourishing, thus fell the basest metal. Pliny reads in it the modest rank that Greek esteem granted this vegetable. The attested fact, however, is limited to this single testimony, with no independent proof of such offerings.
Pline l'Ancien, Histoire naturelle, livre XIX, chap. 26 (Ier siècle apr. J.-C. ; traduction Loeb, Rackham).
The anecdote comes from a single notice by Pliny, the same one that mentions the radish and the beet, and is explicitly attributed to him, for want of external confirmation. The turnip was moreover a widespread staple food in the Roman world, which the image of the lead sums up with irony. No medicinal virtue is asserted here.