Re: Winter Dormancy

Hi all,

That stupid text only conversion made 0 out of the degree signs.
It should be
-5 C = 23F
20 C = 68F
3 C = 39F
25 C = 77F
7 C = 45F
26 C = 79F
Sorry about that but it looked fine on my screen

W. George Schmid
Hosta Hill - Tucker Georgia USA
Zone 7a - 1188 feet AMSL
84-12'-30" West_33-51' North
Outgoing e-mail virus checked by NAV

----- Original Message -----
From: "W. George Schmid" <hostahill@Bellsouth.net>
To: <hosta-open@hort.net>
Sent: Saturday, January 08, 2005 10:09 AM
Subject: Re: Winter Dormancy


> Climate of Japan - Hosta dormancy
>
> The ocean climate of Japan is wet and humid and has four distinct seasons.
> Hokkaido and other parts of northern Japan have long, harsh winters and
> relatively short cool summers. Average temperatures in the northern city
of
> Sapporo dip to -50C/23F in January but reach only 200C/68F in July.
Central
> Japan has cold but short winters and hot, humid summers. In Tokyo,
> temperatures average 30C/39F in January and 250C/77F in July. Kyushu is
> subtropical, with short, mild winters and hot, humid summers. Average
> temperatures in the southern city of Kagoshima are 70C/45F in January and
> 260C/79F) in July. Hosta grow there too! Farther south, the Ryukyu Islands
> are warmer still, with frost-free winters - no hostas there!
> There are  many other factors: elevation (the above temps are at seacoast
> towns), total precipitation, timing of precipitation, soil temperatures,
> soil freezing depth, night temperatures, duration of snow cover, and
shade.
> Spring shade delays soil warming - spring sun advances it. I would say
soil
> temps are the most important. To say 700 hours below 40 is not science.
They
> grow hostas in subtropical Italy, but they put them in pots to be exposed
to
> the much colder night air temps. Another factor is genetic and how the
> species have adapted to warmer climates. The central and southern Japanese
> hostas do fine in the South given enough summer moisture. Did the cultivar
> come from southern species or from northern ones? Or did a particular
clone
> of H. montana come from the North or South in Japan. They grow all over.
> Hostas have a high degree of adaptability. One key seems to be dormancy.
> Delayed dormancy might affect growth rates. If the temps are low enough to
> trigger normal autumn dormancy, the hostas will probably grow there. If
they
> get abundant rain in August/September as they do in Japan (not here in the
> USA), they can stand higher summer and night temps. No rain and above
> 350C/over 90F)during late summer/early fall can make them go heat dormant
> and they will lose a seasons root growth, hence they will decline (as here
> in the South). But given plenty of moisture in late summer in southern
> regions seems to make up for the shorter winter cooling periods and
earlier
> soil warm-up. Up north they may have enough "chilling" but if they dry out
> during the critical root growth period they suffer too. It is a
combination
> of factors!
> There are no fast and hard numbers because no one has scientifically
> determined what they might be. This would be quite a task, because so many
> factors impact the growth rates and survival rates. If anyone out there
has
> real numbers, determined scientifically, I would like to know about them.
> George
>
> W. George Schmid
> Hosta Hill - Tucker Georgia USA
> Zone 7a - 1188 feet AMSL
> 84-12'-30" West_33-51' North
> Outgoing e-mail virus checked by NAV
>
> ----- Original Message -----
> From: "Chick" <chick@bridgewoodgardens.com>
> To: <hosta-open@hort.net>
> Sent: Friday, January 07, 2005 11:17 PM
> Subject: Winter Dormancy
>
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