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 VERNALIZATION AND BIENNIALS

 

Biennial - plants that have a 2 year life cycle:

LIFE CYCLE
1st year - grow vegetatively as rosettes or bulbs in late summer-fall

winter - are vernalized by cold of winter to trigger flower inception

2nd year - in spring flower forms and develops, called bolting
 

GROWTH HABITS
rosettes - radish, carrot, turnip, mustard, kale, bluebonnet, Indian paint brush
heads - cabbage
bulbs - onion

DEFINITIONS
Vernalization - a cold treatment (32-45 oF for 4-12 weeks) required to trigger or initiate
                         flower formation in biennials.
 

Bolting - flower formation and seed stalk elongation in biennials
.

De-Vernalization- exposure (1 day to 1 week) to high temperatures (90-95 oF) immediately 
                              after vernalization, which erases the vernalization treatment.
 

Site of Perception - growing point (apex) of stems.