Why Forsythias Stop Blooming: Pruning Timing or Late Freeze?

Progressive Bloom Loss Over Years

5 forsythias in central IN: 50-yr-old + 4 planted 8 yrs ago. One by one stopped blooming. Leaves grow vigorously. No fertilization. Full AM sun, part PM sun.

Two Main Causes

1. Fall Pruning: Removes flower buds set on old wood. Prune ONLY right after flowering.
2. Late Freeze: Kills tender buds. Weather-dependent, not controllable.

Other Factors

Pests (root/gall weevils) don't stop flowering. Soil test (pH, nutrients) via extension service. Fertilize spring/fall after test.