Kersus

Primary buds start to die near -4°F. Cold-tender; wants a mild winter or protected site.

Needs roughly 2550 growing degree-days to ripen, an early-season variety (Winkler I-II). A mid-length season carries it most years.

Foliar-disease pressure is light for this variety, a routine spray program in a humid climate. One of the easier vines to keep clean.

Susceptible to Pierce's disease. Only a threat in the warm, humid South and parts of California; cold-winter regions cure it naturally.

High vigor. Wants leaner ground and active canopy management, or fruit hides in shade.

Low heat tolerance. Bakes and loses acid on hot sites; favors cooler ground.

Moderate water demand. Average moisture needs for a wine grape.

Prefers soil pH between 6.0 and 7.0. Outside the band, lime or sulfur brings it in range.

Phylloxera-susceptible: plant grafted onto resistant rootstock.