Why Is My Holly Turning Yellow?
The most common cause is iron chlorosis from soil that is too alkaline, which shows as yellow leaves with green veins. Poor drainage, drought, and nutrient shortages also yellow holly. Some spring yellowing and drop of old interior leaves is normal and harmless.
Yellowing holly usually points to the soil rather than a disease. The classic pattern — leaves turning yellow while their veins stay green — is iron chlorosis, and it means the soil pH is too high for holly. In alkaline ground the iron holly needs is locked up and unavailable, even when plenty is present. The lasting fix is to acidify the soil with elemental sulfur or an iron-rich, acid-forming fertilizer, not simply to add nitrogen.
Other causes to check include:
- Poor drainage — soggy soil suffocates and rots roots, yellowing the whole plant.
- Drought stress — dry roots, especially on newly planted hollies, cause yellowing and leaf drop.
- Nutrient shortage — thin, hungry soil produces pale, sparse foliage that a spring feeding corrects.
Finally, do not panic at some yellowing in spring: evergreen hollies naturally shed their oldest inner leaves as new growth emerges, and those leaves yellow and drop first. Widespread or vein-highlighted yellowing is the kind worth investigating.