Hyline Grandiflora has flowers very similar to Hymenocallis littoralis but the leaves are shorter and broader. The bulbs is also larger and more rounded.
 
Plant the bulbs three fourths in a compost comprising of 1 part organic manure, 1 part sand and 2 parts garden soil. Feed and water regularly after the flowering. Dormant bulbs may be lifted and stored till time of planting or left in pots or ground.