01/10/2014
Frost Damage and Preventative Methods for Sub-Tropical and Tropical Trees:
Central Florida, in broad spectrum, is a challenging climate to grow non-temperate plants. Many of us residents simply realize this as we have grown up around citrus groves noticeably frozen over on an icy january morning. Despite this detrimental weather, growers have managed to produce top quality yielding products for generations. These methods and more can often be applied to sub-tropical and tropical fruiting plants in commercial sense or even backyard production.
Sub-tropical plants can tolerate fairly frosty chill hours for brief moments of time, these include crops like papaya, passion fruit, dragon fruit, pineapple, avocados, oranges, grapefruit, lemons, limes and other citrus hybrids. Tropical plants cannot tolerate frost set or freezing chill hours, in fact temperatures below 40 degrees Fahrenheit can often be detrimental. Some of these crops include many of your less common fruits and additionally act as some of my personal favorites like different annona (including sugar and custard apples), black and white sapote, coconuts, mangosteen, miracle fruit, and guava. With either style of these Tropical or Subtropical crops the goal is to prevent cold fronts from moving in and wreaking havoc with wind speeds and freezing temperatures.
Preventative Method 1: MICRO-LOCATION
Attempt to locate a piece of property that provides several key elemental features in effort to keep cold fronts at bay while providing essential conditions for plant life. This location will hopefully provide a well lit area where sunlight and warmth can be obtained even after a frosty night. Elevation is a negative, instead a low land or underlying region is generally better for lesser wind speeds and overall exposer. Often times oak hammocks or other canopies can provide a great protective barrier from frosts and wind although they can also impede upon light exposure which is critical.
Preventative Method 2: STRUCTURES
Plant structures can take almost any form and some of my favorites are the "do it yourself" homemade kind. We are all familiar to some degree with the concept of greenhouses, right? Despite the multitude of styles the purpose in general is to trap natural light and heat, retain it and if possible amplify it to ideal conditions for specified plant matter. But so many of us are not fortunate enough to own one of these large and lovely plant incubators so to speak. For this reason we should use what is commonly and cost effectively available. First, consider which plants are still portable if possible carry them inside the garage, shed, storage unit or even house bring them back outside as soon as the wether is sustainably warm enough. If none of those structures are available consider a porch or little cove/nook against the Southeast side of your house. (all of these further practices can be implemented in accordance with a greenhouse but are often not required). If plants are not mobile focus on creating shelter around it. Old blankets, comforters and tarps are all excellent coverage for you crops so long as they are not too heavy for the canopy. Start by raking whatever compost and leaves onto the trunk of the tree, for temporary purposes we can pile this up to a foot high. Proceed to wrap covering around most of the exposed plant if not all, including the trunk and heart of the canopy. Stakes and supports can be used as well as wire or string to embrace the trees less streamline covering. At this point if citrus or other thick cuticle subtropical crops are the target we can apply sprinkler heads at the base and allow them to run throughout the entire frost. The combined effects of windbreak from the canopy coverage as well as the heat provided to the base by compost and constant water flow creates a miniature "sauna style effect" which increases the plants temperature to some degree.
There are many more applications one can use to protect plants throughout a frost, those are some that have consistently worked for me. I urge you to try your own ideas or others you have read up on and share with other growers in your area. Remember to stay tuned to your local weather channel and always heir on the side of caution because weather people make mistakes too, a lot!
