While these technique aren't practical for most hobby growers, I know of at least a dozen things one can do in a small-orchard situation. They can be grouped as preconditioning procedures and freeze-response procedures. Procedures Preconditioning prepares the plant to withstand cold temperatures without damage. Another nutritional technique is to spray all plant surfaces with kelp seaweed solution. I use Maxicrop dry concentrate at one teaspoon per gallon of water.
Cytokinins present in the seaweed toughen the plant cell walls.
Available from Mellingers. P.O. Box 469, Essex, CT 06426. Available from local farm suppliers. Available from Peaceful Valley Farm Supply. As explained in the literature, these bacterial promote the formation of ice crystals that pierce plant cell walls, leading to desiccation and death.