Hi reffgt,
It dont have to be grown in a pot,althuogh many people do grow them this way, soil should be nutral or acid.
Semi-shade is recomended but the hot dry heat we've experienced of late is probably to blame. badely scorched leaves will not recover but by spraying the plant (not in strong sunlight) occaisionally or applyinga foliar feed during the growing season, it may stop other leaves becoming affected.
A mulch of leaf mould and a regular supply of water around the roots should also help. Good Luck Tbird+