John Jackson, County Extension Agent, UF/IFAS -
Cold protection objectives may vary from grower to grower. Factors such as plant-type and size of a crop need to be considered; some may need to protect an individual plant, while others may want to protect an entire crop. The market value of a crop can play a role as well.
One of the key steps in a successful cold protection plan is to determine the critical temperature – the temperature at which cold air can begin to cause damage - for the plant that needs protection from freezing temperatures. For some plants and crops the critical temperature will not vary during the season or even from year-to-year. Other plants and crops, however, can acquire hardiness during the season. Therefore, the critical temperature for those may change as often as weekly.
The first step in utilizing the FAWN Cold Protection Toolkit requires the selection of the critical temperature for the targeted crop. The links below contain data and observations compiled by University of Florida researchers and Extension agents that may be useful in determining critical temperatures for various crops.