Lemon Daylily

Basic Information

Common Name: Lemon Daylily
Scientific Name: Hemerocallis citrina
Native Habitat: Native to China

History / Discovery / Cultivator

The Lemon Daylily, Hemerocallis citrina, is a long-cultivated species with deep roots in Asian history and horticulture before its introduction to the Western world. Its origins are traced primarily to China, where it has been valued for centuries not just for its ornamental beauty but also for its culinary uses. The unopened flower buds, known as “golden needles” (金针), are a traditional ingredient in Chinese cuisine, used in soups, stews, and other dishes, prized for their unique flavor and texture.

While the exact date of its “discovery” by Western botanists is less documented than some other famous plant introductions, Hemerocallis citrina was among the early daylily species to make its way to Europe and North America. This introduction likely occurred during the wave of botanical explorations and trade that characterized the 18th and 19th centuries, as explorers, missionaries, and traders brought back plants from Asia. Its scientific name, citrina, refers to the lemon-yellow color of its flowers, a defining characteristic.

Unlike some plants linked to a single famous discoverer or cultivator, the history of H. citrina is more a story of enduring appeal and gradual dissemination. For generations in China, it was a staple in gardens and kitchens, its presence so common that its “originator” is lost to time. Its introduction to the West was likely facilitated by multiple individuals and institutions involved in the burgeoning global plant trade. Early botanical gardens and nurseries played a key role in propagating and distributing the species once it arrived.

Hemerocallis citrina gained particular prominence in Western horticulture not only as an attractive garden plant itself but also as a foundational species for hybridization. Its vigorous growth, reliability, long flowering period (often extending into the evening or blooming at night with fragrance), and distinctive flower shape and color made it a valuable parent in breeding programs. Early daylily hybridizers recognized its potential to contribute desirable traits to new cultivars. This extensive use in hybridization means that many of the diverse and colorful daylilies seen in gardens today have H. citrina somewhere in their lineage, contributing to the incredible variety within the Hemerocallis genus.

Thus, the history of the Lemon Daylily is less about a singular moment of discovery and more about its continuous cultural significance in its native land and its foundational role in shaping the landscape of modern ornamental horticulture globally. Its journey from Chinese kitchens and gardens to Western flower beds and breeding labs underscores its versatility and enduring charm.

Plant Care Summary

Botanical Insights

Adaptations

Hemerocallis citrina exhibits several key adaptations that contribute to its success in various environments and as a cultivated plant. One notable adaptation is its robust, fleshy root system, which allows it to store water and nutrients, making it quite tolerant of periods of drought once established. This also contributes to its ability to form dense clumps, outcompeting weeds. The plant’s prolific flowering, often producing many scapes (flower stalks) each season with numerous buds, ensures ample opportunity for reproduction via seed set. Its unique blooming pattern, with fragrant flowers that often open late in the day and remain open through the night, suggests adaptation for pollination by nocturnal or crepuscular visitors, unlike many other daylily species that are primarily day-blooming. This specific timing and strong fragrance help attract the necessary pollinators during certain times. Its ability to thrive in a range of soil types, from heavier clays to lighter sands, as long as drainage is adequate, is another adaptation allowing it to colonize diverse habitats.

Propagation Methods

The most common and easiest method for propagating Hemerocallis citrina is by division. Mature clumps can be dug up, typically in early spring or fall, and carefully separated into smaller sections using a spade or sharp knife. Each section should have a portion of the crown (where the leaves and roots meet) and a healthy amount of roots. These divisions can then be replanted directly. H. citrina can also be propagated from seed, though the resulting plants may not be identical to the parent due to genetic variation if cross-pollination occurred. Seeds are typically sown in trays or directly outdoors after a period of cold stratification.

Toxicology

While the genus Hemerocallis is listed by some sources (like the ASPCA) as having toxicity concerns for cats, specifically potentially causing mild gastrointestinal issues if ingested, Hemerocallis citrina itself is generally considered non-toxic to humans and most common pets, including dogs. The primary concern with Hemerocallis seems to be specific to felines. Symptoms in cats, if they occur after ingesting plant material, might include vomiting, diarrhea, and lethargy. However, compared to lilies (Lilium and Hemerocallis were once grouped, leading to confusion, but they are distinct genera), daylilies are far less dangerous and do not cause the severe kidney failure seen with true lilies in cats. As always, it’s wise to prevent pets from consuming large quantities of any plant material, but H. citrina poses minimal risk, particularly to humans and dogs.

Common Problems

Pests:

• Aphids: Small insects that feed on new growth, causing distortion.
• Spider Mites: Tiny arachnids causing stippling and webbing on leaves, especially in hot, dry conditions.
• Thrips: Slender insects that feed on buds and flowers, causing streaking and distortion.
• Slugs and Snails: Chew holes in leaves, particularly on new foliage.
• Daylily Gall Midge: A small fly whose larvae feed on flower buds, preventing them from opening properly and causing distortion.

Diseases:

• Daylily Rust (Puccinia hemerocallidis): Fungal disease causing orange-yellow pustules on leaves and scapes; can severely weaken plants.
• Daylily Streak (Aureobasidium microstictum): Fungal disease causing reddish-brown streaks on leaves.
• Crown Rot: Fungal issue caused by overly wet conditions, leading to mushy base and eventual plant collapse.
• Root Rot: Similar to crown rot, affecting roots in poorly draining or overly wet soil.

Other:

• Lack of Flowering: Often caused by insufficient sunlight (less than 6 hours), overcrowding of the clump, or overly rich soil promoting foliage over flowers.
• Yellowing Leaves: Can be due to overwatering, underweighting, nutrient deficiency (especially nitrogen), or the natural aging of foliage after blooming.
• Stunted Growth: May indicate poor soil fertility, inadequate watering, excessive competition from other plants, or pest/disease issues affecting the roots or crown.

Rarity & Value

Rarity:

The species Hemerocallis citrina itself is not considered rare in cultivation. It is a widely grown, reliable, and readily available perennial found in nurseries and garden centers across regions suitable for its growth. Its historical significance and use in hybridization have ensured its continued propagation and distribution. While specific cultivars or selections derived from H. citrina might have limited availability, the parent species is common.

Value:

The market value of Hemerocallis citrina is generally moderate. As a common and easy-to-propagate plant, its price point is accessible compared to many newer or rarer hybrid daylily cultivars. Factors affecting the value of a specific specimen typically include its size and maturity (larger, established clumps are worth more than small divisions), overall health and vigor, and the time of year (plants may be more expensive during peak planting or blooming season). Unlike many collector plants, its value is not typically driven by factors like variegation, specific provenance, or extreme demand for novelty, but rather by its basic ornamental appeal and reliability as a garden plant.