Prepare for a Freeze by bringing potted orchids indoors if the forecast is for 50 degrees or below. Water plants well but do not drench if a short freeze is predicted and then keep your irrigation sprinkler off as long as there is a freeze warning. To be honest I haven’t brought any orchid inside for years and they have all somehow survived very cold nights.
Protect tender tree-growing orchids, tomatoes, and tender bloomers from falling temperatures. Move mulch so it doesn’t touch stems of tender, young plants.
See Cold Protection and Chilling Damage of Landscape Plants
Winterize tender plants with liquid seaweed solution (e.g. Maxicrop or Neptune’s Harvest). Use as a foliar spray on both sides of the leaves to strengthen cell walls. Made from kelp harvested from shallow coastal waters liquid seaweed emulsion contains over 70 beneficial plants. About once a week to spray a fine mist of liquid seaweed solution on vegetable plants, citrus and avocado trees. Spray other fruit trees, shrubs and vines about every two weeks.