International Rock Gardener e-magazine

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Harold Peachey
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Title: Member
Joined: 2010-03-22

I always thought that germination/stratification temperatures referred to soil (medium) temperatures so temporal fluctuating air temperatures were misleading.

Harold Peachey
USDA Z5, Onondaga, NY US

Hoy
Hoy's picture
Title: Member
Joined: 2009-12-15

According to Norwegian literature regarding stratification, the most effective temperature is about 5C.

The endogenous dormancy of seeds have several reasons but one is induced by the hormone abscisic acid and ended by the hormone gibberellic acid. This makes it necessary to have a certain metabolic activity.

Trond
Rogaland, Norway - with cool, often rainy summers  (29C max) and mild, often rainy winters (180 cm/year)!

RickR
Title: Moderator
Joined: 2009-09-21

Harold wrote:

I always thought that germination/stratification temperatures referred to soil (medium) temperatures so temporal fluctuating air temperatures were misleading.

Exactly right. Air temperature can only be used insofar as to help generalize what ground temps might be.  Without the knowledge of actual soil temperature, we must realize that air temperature is only one of the factors that affects soil temps.

Rick Rodich    zone 4a.    Annual precipitation ~24 inches
near Minneapolis, Minnesota, USA

RickR
Title: Moderator
Joined: 2009-09-21

Hoy wrote:

According to Norwegian literature regarding stratification, the most effective temperature is about 5C.

That's very interesting, Trond.  If you happen across the data again, I'd be interested in which types of seeds/germination modes were tested.

Rick Rodich    zone 4a.    Annual precipitation ~24 inches
near Minneapolis, Minnesota, USA

Hoy
Hoy's picture
Title: Member
Joined: 2009-12-15

RickR wrote:

Hoy wrote:

According to Norwegian literature regarding stratification, the most effective temperature is about 5C.

That's very interesting, Trond.  If you happen across the data again, I'd be interested in which types of seeds/germination modes were tested.

Ok, I'll keep it in mind.
I found this however, but it is about seeds from forest trees (Abies, Pinus etc).
http://www.skogfroverket.no/Web/Froverksdrift/forbehandling.htm

Trond
Rogaland, Norway - with cool, often rainy summers  (29C max) and mild, often rainy winters (180 cm/year)!

IMYoung
Title: Member
Joined: 2010-01-31

Two years of IRG completed :
the December issue of IRG is now online.

A slight departure from our usual format, as you will discover; there is a calendar for you to print out. :D  
http://www.srgc.org.uk/logs/index.php?log=international

Thanks to all our contributors and helpers over the year and to those who have given encouragement.
To Glassford Sprunt and Richard Green for their proof-reading, Maggi gives particular thanks.

Glassford continues to prepare the IRG Index and the up to date index for all 24 issues is included in the December 2011 issue.

With kindest regards for a Good New Year  from Maggi, ZZ and JI

edit to add cover photo.....

Ian  and/or Margaret Young ( -here it is usually Margaret)

Aberdeen , North East Scotland, UK
Zone 8a

www.srgc.net

cohan
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Joined: 2011-02-03

A lovely calendar- no surprise there :)

west central alberta, canada; just under 1000m; record temps:min -45C/-49F;max 34C/93F; http://picasaweb.google.ca/cactuscactus  http://urbanehillbillycanada.blogspot.com/

IMYoung
Title: Member
Joined: 2010-01-31

Aw, shucks! Thank you Cohan  :-*  Just thought it would be fun!

    m

Ian  and/or Margaret Young ( -here it is usually Margaret)

Aberdeen , North East Scotland, UK
Zone 8a

www.srgc.net

Hoy
Hoy's picture
Title: Member
Joined: 2009-12-15

Thank you Cohan for bringing this  site up! I hadn't looked at it for a while!
And thank you Maggi and all who have contributed to this beautiful magazine! I have now printed the calendar too  ;)

Trond
Rogaland, Norway - with cool, often rainy summers  (29C max) and mild, often rainy winters (180 cm/year)!

IMYoung
Title: Member
Joined: 2010-01-31

Welcome to a new year of IRG.

The January issue is now online, beginning with a look back to some plants that are popular now as they were forty years ago. Some  things never change, it seems.

Grahame Ware explores his affection for a little snapdragon and Fritz Kummert shares his delight in an unassuming Idaho native. 

Ranunculus haastii... photo Doug Logan

Ian  and/or Margaret Young ( -here it is usually Margaret)

Aberdeen , North East Scotland, UK
Zone 8a

www.srgc.net

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