Saturday, July 10, 2010

Chill hours, Orlando area

Someone sent me this interesting calculation of chill hours in Central Florida, based on FAWN temperature data.
I have calculated chill hours for Orlando based on the FAWN weather data. I thought you may find this useful since you have posted similar information on your very informative and interesting blog.



Chill Hours* for Orlando
Winter Calculated
1997 1998 160
1998 1999 184
1999 2000 249
2000 2001 387
2001 2002 196
2002 2003 383
2003 2004 247
2004 2005 203
2005 2006 255
2006 2007 143
2007 2008 136
2008 2009 325
2009 2010 468

Average: 257

Minimum: 136

Maximum: 468

* number of hours the temperature is below 45 degrees F and above 32 degrees F
Of all the complexities of Florida gardening, this one is particularly vexing: We cannot really grow much in the way of tropical fruit like mangoes and bananas. Sure, in a limited way, we have some success--some years, I get more bananas than I can eat. But, as has been the case for the past two winters, other years my bananas get burned down to the ground (delaying fruiting by a year or more), and my mango tree dies despite my best efforts.

So instead of tropical fruits, we try deciduous low-chills, like tropical peaches, persimmons, pomegranates, low-chill apples and pears, etc. Years with cold winters yield heavily, while years with warm winters result in low flowering and fruiting, sometimes no crop at all. This past winter was so cold that my pomegranate is still flowering in mid-July! My peach tree bore heavily, my apple tree set fruit for the first time, and so on.

Having done a lot of shopping for such trees, the sweet spot seems to be 250 hours or more--it really expands the variety of trees (if you believe the chill-hour requirements that growers list... I don't, mostly).

DeLand is a few degrees cooler than Orlando, so it's safe to add ten or twenty hours to the numbers above. That still means that every other year, or maybe every third year, is well under the minimum "ideal" of 250 hours.

So, just barely cold enough for temperate, not quite warm enough for tropical.

I guess there's always citrus!


Mary said...

...and figs. :)

Winter Springs said...

Thanks for the fantastic table! It looks like a few hours of work getting that calculated. I am now planning two or three apple trees for my yard, Anna and Golden Dorsett, so this data is just what I needed. I live in Winter Springs.

Unknown said...

Well I find myself in your same predicament. I moved to West Brevard County (zone 9b) a couple of years ago from South Florida. The previous owner of this property had avocado trees that are consistently cold burned in the winter and die. They recover in the summer but only just. And they never produce fruit. In South Florida I had mango, avocado, and citrus growing in my yard. I was just musing to myself yesterday your very observation. It is too cold to grow most tropical fruit in Central Florida but not cold enough for things like apples, pears, peaches, and apricots. Or so I thought. I am experimenting with some low chill hybrids like Aprium (zone 10), Pluot, and others. I also giving Kiefer pears, Moorpark Apricots, and Lapin Cherries a try. Beyond that I have two Santa Rosa Plums that I expect will be able to thrive here if I can keep the insects under control. Sometimes I wish I had moved just a bit further north near Jacksonville, FL so I could have more options available for fruit trees in my garden. Cheers!