Hail

Hail is the most arbitrary of vineyard hazards. It falls in narrow corridors, so one grower can lose everything while a neighbour a kilometre away loses nothing.

Burgundy, parts of Argentina and the Rhône are among the regions where it is a recurring rather than exceptional risk.

Direct damage removes leaf area, which reduces the vine’s capacity to ripen whatever crop remains, and strips or bruises berries.

Bruised and split berries are an entry point for grey rot and for acetic acid bacteria, so a hailed vineyard close to harvest may face a rot problem on top of the crop loss.

Damage before flowering can be partially compensated by secondary buds, though the resulting crop is smaller and later. Damage after véraison generally cannot be recovered at all.

Protective netting works but is expensive and can shade the canopy. Hail cannons and cloud seeding are used in some regions and their effectiveness is disputed.

Insurance and, in some appellations, rules permitting a grower to blend across vintages or draw on reserve wine are the practical responses.