Vol. 113 (2000): Proceedings of the Florida State Horticultural Society
Krome Memorial Institute (Tropicals)

Freeze protecting Florida blueberries

front cover of vol 113, 2000

Published 2000-12-01

Abstract

Blueberries are grown commercially in Florida from
La Belle north. The plants are cold-hardy if dormant, but lose
cold-hardiness as they come out of dormancy from late Janu
ary through April. Growers use overhead irrigation to protect the flowers, fruit, and tender spring vegetation from freezes. Critical temperatures below which protection will be needed depend on wind speed, dew point, and the stage of development of the flowers and fruit. Cultivars vary in cold tolerance, even when they appear to be at the same stage of flower development. Pine-bark mulch, dry soils, grass strips between the rows, and planting in 'frost pockets' can increase freeze damage on nights with clear skies, light winds, and low dew point. During severe freezes, with low temperatures, high winds, and low dew point, use of overhead irrigation can increase damage to the crop. Overhead irrigation should not be used if evaporative cooling would exceed the heat produced by ice formation. Thoroughly wetting the ground just prior to the freeze can be useful on certain nights when it is too cold to irrigate during the freeze.