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Nicolas Naranja · 12-15-2010, 09:45 PM

Bananas are a little bit different than other plants, they will actually get damaged at above freezing because the sap congeals at low temperatures. Wind can burn leaves, I've seen it with my own eyes in the middle of summer. The question for me is, was it frost last night or was it an actual advective freeze, which is pretty unusual within 1000 feet of lake Okeechobee.

Quote:

Originally Posted by Olafhenny

Hi Nicolas,

wind or no wind, I cannot see how any plant can sustain that kind of damage at above freezing temperatures. It takes ice crystals, which form within cells and crush their structure to create that damage, and not even hurricane strengths winds can accomplish that at temperatures even a fraction above freezing.

Now, when the temps sink below 0^C (32^F) , wind suddenly becomes an important factor, as the faster subfreezing air brushes by the leaves, the faster it will cool and cause the formation of ice crystals within the cells of the leaf.

You are correct, when you assume. that the damage may have occurred prior to the night in question, because the damage only becomes evident after it thaws again. During the frost period the ice crystals still support the leaf structure, but when it thaws, everything crumples. – Just toss a lettuce leaf into your freezer. You will see, that it still looks okay, when you first take it out, but it will quickly turn soft and collapse thereafter.

Best,
Olaf