Why Are My Peony Leaves Turning Yellow?

Peony leaves usually turn yellow because of nutrient deficiencies, poor watering practices, incorrect planting depth, pests, disease, or simply the natural end-of-season cycle. Identifying when and how the yellowing occurs helps diagnose the true cause and find the right fix.

Nutrient Deficiencies

The most common nutritional issues behind yellow peony foliage are:

Nitrogen deficiency: Older leaves turn yellow first, starting from the base of the plant. Growth slows and stems may weaken.
Iron deficiency: Young leaves appear yellow with dark green veins, a clear sign of chlorosis caused by low iron availability.
Magnesium deficiency: Mid-level leaves show yellowing between veins, often with edges that remain green.

Correcting nutrient issues requires balanced feeding. A liquid fertiliser like CompleteGrow All Purpose NPK 20-20-20 replenishes nitrogen, phosphorus, and potassium evenly, while CompleteGrow Advanced Formula 4-18-38 + CaMg provides magnesium and calcium to stabilise growth and restore leaf health.

491444505_18457216702074159_274113386088538550_n (1)

491440652_18457216588074159_5950961339922046381_n (1)

Watering & Soil Problems

Peonies dislike extremes. Both drought stress and waterlogging lead to yellow leaves:

Overwatering: Roots suffocate in soggy soil, turning leaves pale or yellow before wilting.
Underwatering: Dry soil starves roots of moisture, leading to limp, yellow foliage in hot weather.

The fix: water deeply once a week, allow soil to drain fully, and always grow peonies in well-draining beds or containers. Raised beds or amended soils work best in heavy clay regions.

Incorrect Planting Depth

Planting too deep weakens the plant and often shows as pale or yellowing leaves. Peony buds (eyes) should sit no more than 3–5 cm below the soil surface. Deeper planting prevents buds from sensing winter chill and drains root reserves, resulting in unhealthy foliage. The solution is to lift and replant crowns in autumn at the correct depth.

Natural Leaf Yellowing

Peonies naturally yellow at the end of their growing season (late summer into autumn). This is not a problem but part of dormancy, as the plant pulls nutrients back into its roots for next spring. Only be concerned if yellowing appears early in the season or affects new growth.

447780051_491533976777814_1161381868274508416_n (1)

454638674_1241225707008149_9095189342486008958_n (1)

Disease & Pest Issues

While less common, yellowing can also signal disease:

Botrytis blight: Leaves yellow and collapse with grey mould on stems. Often linked to damp conditions and poor airflow.
Leaf spot: Yellow blotches appear between veins, eventually browning. Caused by fungal pathogens.

Improving airflow, avoiding overhead watering, and removing infected leaves reduces fungal spread. Keeping plants well-fed with balanced fertiliser makes them more resistant to disease stress.

FAQs on Yellow Peony Leaves

Why are my peony leaves turning yellow in midsummer? Likely water stress or a nutrient deficiency. Feed with NPK 20-20-20 and check soil moisture.

Why do bottom leaves yellow first? This is classic nitrogen deficiency, as peonies move nutrients from older leaves to new growth. Balanced feeding corrects it quickly.

Can yellow leaves turn green again? If caused by nutrient deficiency and treated early, yes. Leaves damaged by disease or age will not recover but new foliage will emerge healthy.

How do I stop yellowing next year? Feed peonies consistently with CompleteGrow NPK 20-20-20 in spring and 4-18-38 + CaMg at bud stage and post-bloom. Combine with even watering and correct planting depth.

In most cases, yellowing is a sign your peonies need better nutrition or soil care. With shallow planting, steady watering, and seasonal feeding using CompleteGrow fertilisers, peony foliage stays healthy and supports spectacular blooms year after year.