@jaa0109 For the spell Hail of Thorns, does it last for the initial attack or as long as you maintain Concentration? Hail of thorns lasts until you hit a creature with a ranged weapon attack or your concentration ends, whichever comes first.
— Jeremy Crawford (@JeremyECrawford) November 6, 2014
If it only acts once, why it requires concentration and lasts a minute !?
Even more, why it requires an attack that hits and also a saving throw !?
it is unthinkable