Chill Hours in Central Florida

I Want to Thank Michael at Gardening in Central Florida for this data bit.

Chill hours, Orlando area

Someone sent me this interesting calculation of chill hours in Central Florida, based onFAWN 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.

Best,

Thomas

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 stillflowering 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!