In bloom, open (3)
I believe the answer is:
out
I believe this clue is a double definition.
'in bloom' is the first definition.
(flowers might be in bloom or 'out')
'open' is the second definition.
(I've seen this in other clues)
(Other definitions for out that I've seen before include "A way to escape" , "Away from home" , "impossible" , "sleeping" , "For example, caught" .)