The Seeds Take a Full Year to Ripen After the Flower
Witch hazel has an unusual reproductive timeline. The flowers open in October or November. Pollination occurs — by moths, flies, or other late-active insects. But the seeds do not ripen until the following fall, a full twelve months later. This means that at any given moment in late autumn, a witch hazel branch may simultaneously carry open flowers from the current year and mature seed capsules from the previous year's flowers.
The ripe capsule then splits explosively under tension — the woody walls contract as they dry, and the seeds are ejected with enough force to travel up to ten metres. The pop of a witch hazel capsule releasing its seeds is audible, and standing near a plant on a dry fall day when multiple capsules are splitting simultaneously is a genuinely memorable encounter with plant mechanics.