All frost protection methods consist of using one or more of the following principles, according to USDA Agricultural Research Service irrigation ­specialist Dr. Robert Evans:

  1. Good site selection and proper siting of buildings, windbreaks, and fences so cold air drains away
  2. Mixing of the air, using wind machines or helicopters, to use heat stored in the atmosphere and to prevent ­stratification of cold air near the ground
  3. Direct heating of the air using heaters or undertree sprinkling with water
  4. Radiant heating occurs when heaters are glowing red
  5. Release of the latent heat of fusion from water applied to the canopy by overhead or undertree sprinklers and then freezing
  6. Release of the latent heat of condensation using humidification, fogs, or sprinklers
  7.  Radiative heat loss interception using covers or fogs to conserve heat
  8. Use of heat stored in bare soil over time
  9. Thermal insulation by covering with foams or greenhouses
  10. Bloom delay using tree wraps, white paint, or other heat reflective methods
  11. Planting cold-tolerant or late blooming varieties
  12. Genetic development of cold-resistant plants