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