well

you may well be an expert on the plants

but these plants in seattle must have developed into a unique sub
group

the neighbor has a balcony not 15 feet from the plant overlooking it
and in the 3 years it has been there has never seen a flower stalk

i have cut grass, weeds, roses, these plants
for the last 10+ years and never observed anything other than
leaves

so ....................assuming that all the other plants flower each
year, why haven't these 3 and/or what prompted them to do so this
year?