The reason I have to do the fridge method at all is because I have VERY cold winters, and they last a long time..(5 months).. Here in Western NY, we have brutal winters, sub-freezing temps for weeks on end, tons and tons and tons of snow.. its way too severe for Sarracenia and VFT's to survive outside all winter. VFT and Sarracenia need a COOL winter..not a freezing artic winter. VFTs and Sarracenia (all except S. purpurea) are native to the South East USA..where they get a definate winter season, but a cool, somewhat mild winter, with temps in the mid-30's up to the mid 50's.
(+2 to 12 Celsius) sometimes they get snow and a light freeze, but when they do, it only lasts for a day or two and it quickly warms to above freezing again. Its a much less severe winter than here in Rochester.
Those south east USA winters are the conditions that need to be replicated. So..since I cant keep them outdoors, and I dont have a cool basement or an unheated room..what to do? the FRIDGE!
its perfect. temps very cool, but just *above* freezing..about 35 degrees fahrenheit. (2 degrees C)
My plants go into the fridge in the late fall. late October or early November.
whenever the night-time temps begin to seriously fall below freezing. (32F, zero C)
They stay in the fridge all of November, December, January,
and they usually come back out in Mid February..Valentines Day. 3 and 1/2 months dormancy.
but..Mid-February is still the dead of winter here! still far too cold outside.
So they sit indoors in front of a bright window to slowly come out of dormancy.
then, by April or May, they can go back outside for the season..
they remain outside ALL Summer, and then into Autumn..
I keep them outdoors all through August, September and into October, as days and nights
gradually fall into the 60's, 50's, 40's.. (15..10...5C)
I wont even consider bringing them inside unless its going to fall below freezing
or if there is a heavy frost forecast for overnight.
This way, nature creates a natural dormancy for me!
I dont have to do a thing about "making them go dormant"..
they go dormant naturally through all of late summer and into autumn..
then, by the time they are ready for the fridge,
they are already fully "asleep" and are ready to continue that sleep in the fridge..
Please note that the fridge does not cause or create the dormancy!
it simply maintains the dormancy that was already started naturally by keeping the plants outdoors all season..the plants need to be already dormant before they go in the fridge.
In my opinion, VFT's and Sarracenia should never be grown indoors or especially in terrariums..
the climate inside a terrarium is just all-wrong for them..
the climate is fine for a few months...but VFTs and Sarrs need very different climates at different times of year..
Keeping VFTs and Sarrs in a terrarum is the same as trying to grow maple tree bonsai in a terrarium...or attempting to keep a native tree indoors year-round.. you can replicate June through August ok in a terrarium..sunny and warm..but what about the other 9 months of the year?
Maple trees need a gradually warming spring to come out of dormancy, a gradually warmer and sunnier summer, a gradually cooler and darker autumn, then a cold and dark winter to be fully dormant.
so do VFTs and Sarracenia.
its not an option..its a necessity!
If you grow a maple tree indoors it will die within a year...the non-changing environment of a terrarium will also eventually kill a VFT.
VFTs need it warm and REALLY sunny in the summer..DIRECT sunlight..
where can you find that? outdoors in the summer!
Nature provides the perfect light for free..
then you need gradually decreasing photoperiod and gradually decreasing temps from summer into autumn..
where can you find that? outdoors..again nature does all the work for us.
The only tricky season for those of us in the Northern states is the winter..
Spring, Summer and Autumn are a breeze..just keep the plants outdoors April - October.
but the plants need a COOL winter..the winter of South Carolina..
but winters in the northern states are too severe and will kill them if the plants are left outdoors..