apologies in that I missread this book this morning. The correct information is: dormancy in 'dutch ' Iris is initiated by temperatures greater than 17 C. Optimum temperatures for initiating flowering shoots are 8 to10 C for 6 - 9 weeks, depending on the variety Page 84, Ornamental Geophytes Peter (UK) On Fri, Nov 22, 2013 at 4:21 PM, M. Gastil-Buhl <gastil.buhl@gmail.com>wrote: > > Peter has been doing my homework for me, reading that thick textbook. > He writes: > "Temperatures less than 17 C apparently act as chilling for certain > 'dutch' Iris for example." > >