Florida FREEZE and Tropical Plant Damage: Coldest Since 1989

[JonathanBelles]

I've heard that I-4 may be affected or currently effected.

[JonathanBelles]

10 sinkholes have opened up in central Florida, and ALL of them are growing. Dozens more could open up. I-4 and US27 are both closed in sections, and traffic is backed up all the way to Sefner and Tampa. Polk and Hillsborough Cos. will be having problems for many weeks ahead. Radar is being used across most interstates to ensure more interstates do not fall. As I said this morning, there is a sinkhole that has opened up in Dover under a strawberry farm because of the massive amounts of frosty nights in recent weeks.

[vbhoutex]

I lived in Florida for many years and I know there were many sinkholes all across the state, but I have never heard about "frostquake" sinkholes. What causes these? The ground isn't getting frozen so that isn't the problem or at least I don't think it is.

[JonathanBelles]

Basically what happens is frost forms on the ground and when water freezes, it expands the ground similar to an icecube in a tray. Then the frost melts, and the ground has to settle again. Frost melts much faster than it forms. The ground settles much faster than it expanded and with the limestone, caverns, sand, and poreous nature of the Florida landscape it falls so fast the ground underneath cannot hold the falling soil up, so it continues to fall. Sinkholes open up from this process. This is what I have observed and how it has been explained to me. The term frostquake comes from up north, where it is much more common but far less damaging due to soil differences.

[psyclone]

the sinkholes are strictly a result of farmers drawing down the water table in an effort to save their crops. they have nothing to do with the ground freezing. this is why they are taking place in heavily agricultural regions as those areas have experienced the heaviest water use. folks with wells in the plant city area know to turn off their pumps at night when the farmers are spraying their crops...otherwise their pumps could burn up when the water table drops. if we get heavy rain this weekend the threat of sinkholes will actually increase with the added weight load on the surface soil. this particular episode of sinkholes is more severe than usual due to the exceptionally long duration of cold drawing down the water table to a much greater extent than a normal cold snap would.

[JonathanBelles]

My own frost and freeze pictures from 1/11/10 (Click to zoom):

[NDG]

I agree with psyclone, frost has nothing to do with causing the sinkholes (most ridiculous thing I've heard), when we have a frosty morning it does not mean that the ground is frozen, farmers drawing ground water is the most probable cause.

[NDG]

Another thing, I would not consider this freeze event as damaging as 1989 when temps dipped a lot lower, but then again the continuous number of nights of freezing temps that we have seen is probably just as damaging.

[psyclone]

getting back to the original point of this thread, there is widespread, significant freeze damage to sensitive, exposed tropicals around here. hibiscus and bouganvillia have been heavily damaged and some of these plants may have been killed outright. the offending night was last sunday night/monday morning. the damage extends right to the coast as i found exposed bougavillias right on the waterfront in dunedin that have been reduced to kindling. even the mangroves that extend inland on creeks and canals show burned tops. plants that were protected (ie under trees or the eves of buildings) overall fared well with minimal damage. this is definitely the most extensive freeze damage i have observed during my time here. not a knockout blow (we have our extensive tree canopy to thank for that) but quite ugly nontheless. on the beach the cold effects didn't manifest themselves as plant damage but something more insidious...dead fish. it is apparent we had a big cold related fish kill and many of those fish are washing up on the beach. as the water temp rebounds i suspect more dead fish that sank will float as they decompose resulting in even more dead fish coming ashore (yuck!). this is a huge disappointment to fisherman as our fish population was just getting back to normal after a devastating red tide episode in 2005 eviscerated our aquatic wildlife. i hope we're done with the cold.

[gatorcane]

Another thing, I would not consider this freeze event as damaging as 1989 when temps dipped a lot lower, but then again the continuous number of nights of freezing temps that we have seen is probably just as damaging.

Indeed, here across South FL, we are still seeing the effects of this freeze, even 6+ months later deep into the summer. The most notable damage is to the coconut palms. I would say roughly 25% or 1 in 4 coconut palms growing in South FL have died because of the freeze. But some areas were spared while others saw over 90% death rates. They didn't just die immediately, they took *many* months to show the fatal effects of the freeze. Typically a couple of days to a coupld of weeks after a freeze you may see the palm fronds acquire a "burned" appearance, especially the lower and middle fronds, leaving the center, new fronds OK. But this freeze was different and I think the main difference was not just the freeze, but the duration of the cold and the extreme winds we saw from El Nino this winter in S. Florida which also caused damage.

What I am seeing is that new palm fronds that want to shoot out in the middle of the palm grow partially then snap off in the middle of the palm. Eventually the entire palm frond falls down to the trunk of the frond. Then if the palm tree cannot fight this off with new fronds that don't snap, the entire crown of the palm eventually falls over due to freeze damage to some or all of the inner trunk of the palm just below the crown.

This is an interesting article from researchers at the University of Florida which discusses the freeze damage to palm trees in S. Florida:

http://charlotte.ifas.ufl.edu/publicati ... photos.pdf