Reliably winter hardy to USDA Zone 8. In St. Louis, bulbs must be lifted in fall. Best grown in moist, humusy, well-drained soils in full sun to part shade. Soils must never be allowed to dry out. Plant bulbs 4” deep and space 8-12” apart in mid-spring. Garden grown bulbs must be lifted in fall after foliage die back and before first frost. Dig carefully (try to retain as much root as possible), dry and store in a cool, dry location (50s) in a dry medium such as peat or perlite. For containers, plant in spring with the necks of the bulbs slightly above the soil surface. Container grown bulbs may be overwintered in the containers by withdrawing moisture as the foliage begins to die back and storing pots indoors in a cool, dry location.
Hymenocallis x festalis is commonly called spider lily, basket lily and Peruvian daffodil. It is a deciduous, bulbous, hybrid perennial of garden origin that looks like a spidery daffodil with extremely narrow perianth (petal-like) segments. Features a basal clump of linear, strap-shaped, amaryllis-like leaves (each to 36” long) growing directly from the bulb. In summer, from the center of the foliage rises a solid scape (to 30” tall) that is topped by an umbel of 2-5 fragrant, white, spidery flowers (to 5” across). Each flower has six (6) extremely narrow, outward-spreading-to-reflexed perianth segments and a daffodil-like staminal center cup (corona). ‘Zwanenburg’ is noted for having large white flowers with scalloped-edged cups. Synonymous with Ismene x festalis ‘Zwanenburg’.
No serious insect or disease problems. Snails, caterpillars and mealy bugs are occasional visitors.
Best in borders, open woodland gardens. Containers.