Ahhh...I was unclear. Sorry.

Yes, I should have differentiated between temperate climate fruits, tropical
fruits, and subtropical fruits.

Temperate climate fruits (like the cherries we were discussing, plus apples,
pears, peaches, etc.) have high minimum chilling requirements. Cold
hardiness varies a lot, but temperate fruit trees will generally survive
temperatures below zero.

You are right that tropical fruits (like mangos and most citrus fruits) need
no chill hours at all. And yes, many tropical fruit trees can tolerate
little or no frost. Some are a little hardier, but will be still be damaged
or killed by temperatures in the mid-to-upper 20s.

There are also a some fruits that are adapted to "subtropical" and "mild
temperate" climates, such as mandarin oranges, limequats, loquats, figs,
etc. They usually have a low chilling requirement (50-150 hours) or no
chilling requirement at all. These trees usually perform better in areas
that at least have a "cool season" than in a truly tropical climate.
Subtropicals will generally survive temperatures into the teens or single
digits.

Regarding citrus trees in particular, there's a wide range of cold
hardiness. Key lime trees are damaged by even a hint of frost. OTOH,
mandarin orange and limequat trees tolerate temperatures into the lower
teens. Grapefruit and orange trees are in the middle - some cultivars can
withstand temperatures into the mid-20s. The fruits themselves are usually
damaged by temperatures of 28 degrees or below for four hours - smaller
fruit will freeze faster than larger fruit.

Where you live, I think you could grow most any citrus except limes and
lemons. You *might* be able to grow limes (other than key limes) and lemons
if you had a way to protect the trees from freezes.

Regarding wind chill, I read somewhere on the IFAS site (forgot to bookmark
the page, unfortunately) that you can't consider wind chill when counting
chill hours for fruit trees. Wish I had the link for you.

Thanks for the FAWN link. It's not the link I was referring to; I had
actually found a map of the state of Florida showing the average chill hours
in each part of the state. I still can't find that chill hours map; maybe
IFAS doesn't have it on their site anymore.

Unfortunately, all of the sites the FAWN link lists for N Florida are well
inland of me, and so the chilling hours at those sites are a lot higher than
the chilling hours in my yard. Maybe one day they'll add an observation site
closer to me.

In any case, if you decide you want to grow some fruit trees, your county
agricultural extension office will be happy to tell you exactly which ones
grow best in your area. They should be listed in your telephone book.

Laura



"Jim Carlock" wrote in message
. ..
Thanks Laura,

I think this is probably the link you were looking for. I was hoping
they'd have a visual map, but the chart below works well enough.
I live in St. Petersburg, FL, which is right on the Gulf, a peninsula
surrounded by water, the Gulf of Mexico on one side, Tampa Bay
on the other. Sea Manatee roam the coast line and we're getting
a good amount of hurricane rain. Bradenton is just south of us. St.
Petersburg is urbanized for the most part, a lot of tar and asphalt.
:-)

http://fawn.ifas.ufl.edu/data/chart_historical.asp

As far as fruit trees, I think your statement might need to be
qualified a little further. Oranges, mangos, avocados grow
pretty good all over central and southern Florida. The chill
days, like you said, tend to be very low. If wind chill is counted,
that might help.

I don't think the chill days apply to oranges, lemons or grapefruits,
but I don't have a clue. Usually if there's a freeze the orange
groves complain about losses of fruit. But that tends to only
occur when it actually freezes for a week or more. It's been
a while since Florida has had one of those freezes. Please
correct me if I'm wrong about the oranges and grapefruit
and lemons and limes. :-) Please confirm if I'm correct. I
just don't have a clue and I'm basing what I'm saying upon
old news in the past (about 1979).

--
Jim Carlock
http://www.microcosmotalk.com/
Post replies to the newsgroup.

"Laura Stanley" wrote:
Florida has a much larger range of climates than most people
realize. About the only accurate generalizations you can make
about Florida climates a

(1) summers are hot and LONG, and (2) snow is VERY rare.

In answer to your question, fruit trees that get insufficient chill
hours bloom poorly (few blooms over an extended period instead
of lots of blooms all at once) or don't bloom at all. Leaf out will
also be late and/or sparse, and the tree's growth can be reduced.

It's my understanding that if a tree gets sufficient chill hours
*most* years but experiences an occasional winter that's too
warm, the tree will be OK, although it will bear little to no
fruit during the season following the warm winter.

However, if the tree receives insufficient chilling hours every
year, it will weaken and die within a few years.

Down in Tampa, you probably only get about 200 chilling
hours/year (less if you're very close to the bay/Gulf). So, a
cherry tree would be out of the question.

This link from the University of Florida's Institute of Food
and Agricultural Sciences (UF IFAS) will give you an idea
of what fruits you *can* reasonably expect to grow, if you're
interested in fruits other than cherries:

http://edis.ifas.ufl.edu/BODY_MG248

IFAS also has a map showing average chill hours for each part
of the state, but I've lost my link to it, and I don't have time to
find it again now. If you search around on the IFAS website
you should be able to find it.

Good luck,
Laura

"Jim Carlock" typed:
Wow... I'm in Tampa. The average daily temp here is 72
to 78 degrees over the year.

I've never seen a cherry tree here. The cherry trees I've
seen were up in the states of Washington, Oregon and
Vancouver, Canada.

I've been reading that they won't bear fruit without a
freeze. Or will the whole tree just be stressed and die
off ?

Thanks for the reply.
--

"Christopher Green" wrote:
"Jim Carlock" wrote:
Does anyone know if it's possible to get cherry trees growing
in Florida ? I've been reading that they require a frost to
become fruitful so I don't think they will grow any fruit, but
I'm willing to try. I've got some seeds that have been sitting
in the fridge for about two months that were taken out of
some cherries that were eaten. They've been sitting in the
fridge for two months in a cup of moist peat moss.

Cherries won't thrive without substantial winter chill. Standard
cherries such as Bing need at least 600 to 800 hours below freezing
every winter. (I think Rainier needs the least, about 600 hours.) I
don't know where in Florida you'd find such a location.
--
Chris Green