Why Are My Beetroot Leaves Turning Red or Purple?

Beetroot is a plant that naturally contains betalain pigments — the same red and purple compounds that make the root so richly coloured. These pigments are always present in beetroot leaves, and healthy plants show leaf veins and undersides that are distinctly red or purple. However, when the entire leaf blade turns very deeply red, purple, or almost maroon — losing the green of the leaf surface — this is a sign of phosphorus deficiency, cold temperature stress, or simply the variety genetics. Distinguishing between these helps you decide whether action is needed.

Cold temperature response

Young beetroot plants in early spring often develop intensely red or purple leaves when temperatures are consistently below 10°C. Cold inhibits chlorophyll synthesis and allows the red betalain pigments to dominate the colour of the leaf. As temperatures rise and the plant grows more actively, the leaves return to their normal green-red mix and the problem resolves without intervention. This is particularly common in plants grown under cover in early spring or in late-April outdoor sowings during a cold snap. Simply wait — if temperatures are the cause, leaves green up within two to three weeks of warm weather.

Phosphorus deficiency

Phosphorus deficiency produces a similar intensification of red and purple pigments in leaves, but persists beyond the spring warming period and is seen across all leaf ages rather than just young growth. Phosphorus is most commonly unavailable in acid soils (below pH 6.0) or very cold soils where soil chemistry is sluggish. If the leaves remain purple in warm growing conditions, check soil pH — beetroot grows best at pH 6.5–7.5. On acid soils, lime to raise pH into the ideal range; on neutral to slightly alkaline soils, incorporate well-rotted compost before sowing to improve phosphorus availability.

Variety genetics

Some beetroot varieties, particularly heritage types like Chioggia or some yellow varieties, have leaves that are naturally more intensely coloured than others. The variety Bull's Blood is grown specifically as a salad leaf crop for its deeply red, almost maroon foliage — this is entirely normal and intentional. If red leaves appeared with a new variety and the plants are otherwise growing well and forming good roots, the colouring is likely genetic rather than a deficiency.