Why Are My Artichoke Leaves Turning Yellow?

Yellowing leaves on artichoke plants are a common sight and, depending on which leaves are affected and when it is happening, may signal anything from a completely normal seasonal process to a serious root problem. The location of the yellowing within the plant — old lower leaves versus new central leaves — and the time of year it is occurring both tell you whether intervention is needed and what form that intervention should take.

Natural senescence of lower leaves

From late summer through autumn, the lowest, oldest leaves on artichoke plants naturally yellow and die back. This is the normal seasonal cycle — the plant is not diseased and no treatment is needed. Remove yellowing and dead leaves to improve air circulation and reduce the humid microclimate that encourages fungal problems. These leaves can go on the compost heap unless they show signs of disease.

Nitrogen deficiency

When yellowing is widespread across the plant — affecting medium-aged as well as old leaves — and the plant looks generally pale and unhealthy, nitrogen deficiency is the most likely cause. Artichokes are greedy feeders and deplete soil nitrogen rapidly. Apply a balanced fertiliser or a liquid feed high in nitrogen in spring and again in summer. A mulch of well-rotted manure incorporates both nutrition and moisture retention in one application.

Waterlogging

Waterlogged roots cause yellowing of leaves that progresses upward from the base of the plant as the root system deteriorates in anaerobic conditions. The plant may also look generally wilted even when the soil is wet — a paradoxical sign of root failure rather than drought. Artichokes are particularly sensitive to winter waterlogging, which is a common cause of plant death. Improve drainage or raise the planting level to prevent water standing around the crown.

Crown rot

Crown rot (usually caused by Pythium or Sclerotinia species) causes a sudden collapse of the crown tissue, with yellowing and wilting spreading rapidly from the centre of the plant outward. This is more sudden than nutrient-related yellowing and often results in complete plant loss within days. There is no effective treatment — remove and destroy affected plants and do not replant artichokes in the same spot for at least two years.