Iris ensata:

I remember the Iris ensata sown early March 2005 only took one month to germinate.  This year (2006) seed was sown early January, it is starting to germinate now, March 26th, after sitting dormant for what felt like the longest time. 

 

Both seed lots were given the identical treatment with the warm water presoak to soften the spongy seed outer layer for easy removal and the 24 hour 'LifeForce' soak of the cleaned seed.  Quite a job removing the spongy layer on a large quantity of seeds, but the pre soak makes it easy.  Both seed lots remained in the unheated greenhouse and never saw cold temps.

 

It appears both seed lots germinate at the same time of year.  Its very possible the seed is photo sensitive and needs 12 hours of light to germinate...again a survival mechanism preventing the seed from breaking dormancy too soon in the unfavourable environmental conditions of winter.

 

It would be interesting what others have to say about Iris ensata germination when sown at different times of year.