Lilium bolanderi germination

Diane Whitehead
Fri, 19 Jan 2007 20:46:07 PST
I think I had better explain about my temperatures because I think  
many Americans keep their houses warmer than I do.

The unheated bedroom I mentioned is currently 13C (55F), and the  
unheated greenhouse is 9C (48F).  This is nighttime, but the  
temperatures don't vary much.

My kitchen temperature does vary - right now it is a nice warm 20C  
(68F) because I've been baking. It will be lower when I turn down the  
thermostat to go to bed.  This is about the same temperature it will  
be all summer, but of course, with the heater turned off.

  Those lilies of mine generally germinated either in the spring or  
the fall, when temperatures were moderate.  There was just one  
vollmeri that germinated in August.

Our summer temperatures are temperate, and even in my greenhouse,  
which will be warmer than my house, the temperature will be about the  
low to mid twenties celsius (low 70s fahrenheit).  Every five or so  
years we get a heatwave for a day or so when the temperature gets to  
almost 30 (more than 80F).

So you can see that the American lilies germinate at low  
temperatures.  Perhaps if the ones that required almost a year to  
germinate (washingtonianum) had been started in early fall, or  
whenever they are ripe, they might have germinated in the spring.   
Maybe they slowed down because of the warm summer temperature and  
didn't germinate until the temperature cooled in the fall.  This is  
the way most of our plants behave:  their seeds germinate with our  
fall rains when they encounter cooler temperatures as well as moisture.

Diane Whitehead

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