Why Hydrangeas Fail to Bloom: Pruning, pH, and Phosphorus Solutions

Non-blooming hydrangeas after 4 years in zone 6 with morning sun need:

• Prune early spring before buds: remove dead canes, cut 1/3 oldest to ground.
• Early fall: prune 1/4 to promote next spring’s buds.
• Soil pH ~6 (slightly acidic): add gypsum or sulfur if higher.
• High phosphorus: amend with compost, humus, aged manure; fertilize early spring with high-phosphorus fertilizer (middle number double the first).