How to Grow and Care for Japanese Lilies

Japanese lilies are known for their fragrant and elegant blooms that arrive in the late summer garden. Originating from Japan, these plants bring grace to perennial borders and cutting gardens. Their large flowers and tall stems make them a focal point, providing a final burst of color as other plants begin to fade.

Identifying Japanese Lilies

The term “Japanese lily” primarily refers to two species, Lilium speciosum and Lilium auratum, and the many Oriental hybrids derived from them. A key identifying feature is the shape of their petals, which are recurved, meaning they curve backward to give the bloom an open, star-like appearance. The flowers are large, reaching six to eight inches across, with a strong, spicy fragrance.

Lilium auratum, the goldband lily, has a yellow stripe down the center of each white petal and is decorated with crimson freckles. Lilium speciosum features similarly shaped flowers in shades of white and pink, covered in raised, dark-pink spots.

Oriental hybrids combine these traits, resulting in robust plants with large, fragrant, outward-facing flowers. The foliage consists of glossy, lance-shaped leaves arranged around a tall stem.

Popular Types and Varieties

Gardeners have a wide selection of Japanese lilies to choose from. Cultivars of the original species include Lilium auratum var. platyphyllum, a vigorous goldband lily, and Lilium speciosum cultivars like ‘Album’ (pure white) and ‘Uchida’ (deep pink). The most popular choices are often the Oriental hybrids, which were bred from these Japanese species.

Orienpet (OT) hybrids, crosses between Oriental and Trumpet lilies, are also excellent choices for their hardiness. Popular varieties include:

• ‘Stargazer’: Famous for its upward-facing, deep crimson-pink flowers with white edges and an intense perfume.
• ‘Starfighter’: Features even larger flowers than ‘Stargazer’ on shorter stems.
• ‘Casa Blanca’: A widely available choice producing large, pristine white flowers with a powerful scent.
• ‘Journey’s End’: Known for its large, ruffled pink blooms.
• ‘Black Beauty’: An Orienpet hybrid that combines large, fragrant flowers with the heat tolerance of Trumpet lilies.

Planting and Growing Guide

When to Plant

The best time to plant Japanese lily bulbs is in the fall, allowing them to establish a root system before winter. Planting can also be done in early spring as soon as the soil is workable, though fall planting often results in more robust first-season growth.

Where to Plant

Japanese lilies perform best with full sun to partial shade. An ideal spot provides at least six hours of morning sun with some afternoon protection, as the flowers need sun but the roots prefer to stay cool. Because many varieties grow tall, plant them in a location sheltered from strong winds to prevent the stems from breaking.

Soil and Planting Depth

Proper soil preparation is important for preventing bulb rot. These lilies require well-draining soil and will not tolerate “wet feet” or waterlogged conditions. Amending heavy clay or sandy soils with organic matter like compost will improve texture and fertility. Plant the bulbs to a depth of about three times their height, which is around six to eight inches deep. Space them 12 to 18 inches apart to ensure good air circulation. Japanese lilies prefer a slightly acidic to neutral soil pH.

Watering and Fertilizing

After planting, water the bulbs thoroughly. Throughout the growing season, provide consistent moisture, ensuring the soil remains evenly moist but not saturated. During active growth and flowering, they may need watering once or twice a week, especially during dry spells. In early spring as new growth emerges, use a balanced fertilizer low in nitrogen, such as a 5-10-10 formulation, to promote strong bulb and flower development.

Support and Aftercare

Taller varieties of Japanese lilies, especially those with large flower heads, may require staking to keep them upright. Insert stakes at the time of planting or early in the season to avoid damaging the bulb and roots. After a flower has faded, deadhead it by snipping it off to prevent the plant from expending energy on seed production. Allow the foliage to die back naturally in the fall, as the leaves are gathering energy for the following year’s blooms.

Common Pests and Diseases

The red lily leaf beetle is a significant threat. Both the adult beetle and its larvae feed on the leaves, stems, and flower buds, causing damage. The most effective control method is to hand-pick the adults and larvae and drop them into a bucket of soapy water. For heavier infestations, neem oil can be applied, but it is most effective on the young larvae.

Aphids are another common pest that feeds on plant sap, causing distorted growth. A strong spray of water from a hose can dislodge them, or they can be treated with insecticidal soap.

In damp or humid conditions, botrytis blight, also known as gray mold, can become an issue. This fungal disease appears as grayish-brown spots on the leaves, stems, and flowers, which can quickly rot and collapse. To prevent botrytis, ensure lilies have good air circulation by spacing them properly, avoid overhead watering, and remove affected plant material promptly.

Toxicity Warning

All parts of the Japanese lily are extremely toxic to cats. Ingesting even a small amount of a leaf, flower, or pollen can cause severe and often fatal kidney failure. Cats can also be poisoned by drinking water from a vase that has held lilies. Due to this high toxicity, households with cats should not keep these lilies in their homes or gardens.

For dogs and humans, the toxicity is much lower, causing mild gastrointestinal upset if large quantities are ingested. The primary danger is to felines, and choosing a non-toxic flower is the safest course of action for cat owners.