Tall daylilies (Hemerocallis altissima) are a group of late season fragrant daylilies that are native to southwest China, singled out for their tall 5-6 feet floral spikes. Blooms open in late afternoon and are classified as “nocturnal bloomers”. In spring, this deciduous perennial starts out with 2-feet tall grass-like foliage. In summer they produce tall flower spikes 4 – 6 feet tall and 1 – 2 feet wide, adorned with fragrant, pure yellow flowers. Yellow shades of flowers open approximately 4-8 p.m. and remain open thru the next morning. (USDA hardiness zones 3-9).

Daylilies thrive with full sun all day long yet bloom satisfactorily with 6 hours of full sun. Clumps tolerate a wide range of soil types and conditions including briefly soggy soil. Altissima daylilies handle short dry spells lasting 10-14 days, but they perform poorly on chronically dry sites.

The floral display of H. altissima are big, bold and bright. Rate these late bloomers as season extenders. Most daylily cultivars, including rebloomers, flower over many weeks from June into mid-July and rebloomers return in mid-September into October. Night blooming H. altissima daylilies offer additional excitement to the evening garden. Plant where they can be enjoyed in the evening such as a patio or a window.

As a rule, tall daylilies are low maintenance. After flowering ends, snip off the spent bloom stalks and crop off some grassy growth. Lightly fertilize as fresh new foliage emerges in late summer. Irrigate as needed. After a hard frost, mow off daylily foliage at 4–5-inch setting. Fall/winter clean up takes only a few minutes per plant.

Easy care is the rule. H. altissima grow in a wide range of soils. Plant in garden beds along walkways and around patios or in containers where you may enjoy their tall flowers and their evening fragrance. Daylily petals are edible and great in salads. Pollinator attractors include hummingbirds, butterflies, and bees. Inspect spring and summer foliage for aphids. Unfortunately, deer also enjoy their blooms and foliage. Stake some varieties that sometimes flop under the weight of flowers @ 25-30 buds per stem.

Hemerocallis altissima, syn. var. citrina, is a little-known, fragrant daylily species native to southwest China, characterized by its tall floral spikes and nocturnal blooming habits.

Leading Varieties:

‘Autumn Minaret’ – (A.B. Stout introduction) – fragrant, 4.5-inch-wide yellow flowers with a dark peachy “eye” inner throat; 75-inch-tall bloom scape (late season bloomer)

‘Challenger’ – (A.B. Stout introduction) – fragrant, 5-inch-wide brick red with a golden heart and creamy-yellow midribs; 54-inch-tall bloom scape.

‘Notify Ground Crew’, (Curt Hanson introduction) – fragrant, 5-inch-wide yellow blooms (tetraploid), well-branched floral scapes over 6 feet tall; well branched, open after 4 p.m. daily.

H. citrina var. ‘Citrina’ – 4-inch-wide lemon yellow flowers on 4-5 feet tall stalks; June-July bloomer opens after 6 p.m. daily