The warmer temperatures will push the bloom time forward, as long as
two other conditions are met.
1) proper amount of vernalizaton temperature.
2) Daylight above a certain number of hours of sunlight.
In a cold greenhouse, you will actually increase the vernaliation
hours, as the proper temperature is from 2-10C. Below the ideal of
about 4C, the hours are not as effective. And usually below freezing
hours don't clock on most plants, although some will continue to
vernalize as low as -5C.
If you are looking for only a couple of weeks, then no need for
suplimental light. If looking for a month or more, then I would suggest
extra light as well as extra heat.
For time from extra warmth to bloom, figure it on time from warmer
spring weather to bloom in your climate, about two months for me, in
Southern Ontario.
These are general scientific principals, not based specifically on any
experience with forcing siberian iris.
Chuck Chapman
-----Original Message-----
From: Christy Hensler <hensler@povn.com>
To: sibrob@yahoogroups.com
Sent: Wed, 18 Mar 2009 9:34 am
Subject: Re: [sibrob] Re: forcing Siberians
Hi Judy,
It's been my experience that Siberians react as
temperature sensitive (rather than day length sensitive) and the few
times I've
wanted to push the bloom time up, I've simply put them into a warm
greenhouse
and gotten a jump of about 2-3 weeks over those in the garden.
Christy
