that is impatiens and they like well drained soil, shade (morning sun ok) and do not let them dry out between watering.
Light fertilizer is beneficial, and you do not need to prune, clean the dead blooms or anything like that.
It is NOT winter hardy and will not even tolerate frost or lower temps-it will drop its leaves and then die. If you want to overwinter it, bring it indoors in the fall when temps start to go below 45 or thereabouts.
