These fragrant, exotic-looking flowers are relatives of the amaryllis. The bulbs are winter hardy perennials in zones 8-10. In cooler areas the bulbs may be planted in spring for flowers in mid to late summer. Also known as Ismene, the common names for hymenocallis include spider lily, Peruvian daffodil and summer daffodil.
The flowers of hymenocallis resemble daffodils, with a central cup surrounded by petals that are typically narrower and longer than those of a daffodil. The color of the flowers is usually white, though some are cream or yellow. The blossoms are intensely fragrant, especially after dusk.
Hymenocallis have long, strappy leaves like an amaryllis. The leaves typically emerge first, followed by the flower stalk with a cluster of 3 to 5 buds. Overall height including the flowers is about 2’ tall.
In areas where the bulbs are hardy (zones 8-10), they may be planted directly into the garden. Choose a sunny or mostly sunny spot that provides some shelter from wind. Most importantly, make sure the soil is very well drained. Hymenocallis need moisture in the spring, but the soil should be quite dry during summer, fall and winter.
In colder areas, hymenocallis are usually grown in pots. This makes it easy to provide the well-drained growing conditions they need. It also makes it easy to bring the bulbs indoors for the winter. Choose a pot that will provide ample root space. Like amaryllis, the bulbs produce lots of fleshy roots and they need enough room to expand.
When planting, the bulb should be buried and the neck should be even with the soil surface.
Once the bulbs have sprouted and are in active growth, water them as often as needed to keep the soil evenly moist. Fertilize monthly. After the flowers have faded, you may either discard the bulbs or save them for next year.
If you want to save the bulbs, remove the flower stalk after the flowers have faded. Allow the leaves to continue growing and continue to fertilize monthly. Stop watering when the leaves begin to yellow. If the bulbs are in pots, move them to a place where the soil will stay dry.
In zones 3-7 the bulbs need to be brought indoors before the first frost. Put them in a cool place (55-60°F) for the winter and keep the soil dry. When spring comes, check to see if the bulbs are root-bound. If so, transplant to a larger pot. Move the pot outdoors after all danger of frost.