TechNotes Tips - 02.07.02

Frost occurs under clear sky and windless nights. The formation of ice crystals on the leaf is dependent on the dew point, or frost point, which is the temperature that air must be cooled to, in order to cause atmospheric moisture to condense and freeze. There are two types of frost. A white frost results when moisture freezes in small ice crystals on the leaf. During a black frost, few, if any, ice crystals form because the air is too dry. Frost injury to turf is usually of minor damage. The leaves become brittle and if traffic is placed on the turf, the leaf blades are often crushed. As long as the crown of the plant nor any of the other growing points (ex. rhizomes) are not damaged, new leaf blades will be generated once growth is initiated.

Hollies are susceptible to winter injury if placed in exposed areas. Foliage symptoms appear brown and have a scorched look. The buds and branches are normally dead and if leaves do emerge, they often collapse. Additional symptoms include twig dieback and bark splitting. For more information on growing hollies in the southeastern United States see:

http://hgic.clemson.edu/factsheets/HGIC1066.htm