Selenicereus grandiflorus (Queen of the Night)

Selenicereus grandiflorus, commonly known as the Queen of the Night, is an awe-inspiring cactus famed for its large, fragrant flowers that bloom at night. This climbing species has long, slender stems that trail or cling to nearby supports. Its ethereal beauty comes from the spectacular blooms, which last only a few hours but leave a lasting impression with their enchanting scent and intricate structure.

Selenicereus grandiflorus should not be confused with epiphyllum oxypetalum, another plant known as Queen of The Night Cactus.

The Queen of the Night Cactus is a member of the Cactaceae family, which also includes the popular Chrismas cactus, prickly pear (opuntia), pincushion cactus (mammillaria), and the iconic saguaro cactus and San Pedro cactus.

Description

The Queen of the Night Cactus is a climbing cactus known for its long, thin, and sprawling stems that grow over time into a tangled, vine-like structure. The stems are green and ribbed, often producing aerial roots to anchor themselves onto other surfaces. The plant’s most notable feature is its large, white flowers with a sweet, intoxicating fragrance.

The flowers of this cactus are among the largest in the cactus world. They bloom at night, with each flower opening for a single night.

Native Habitat

The Queen of the Night Cactus is native to Central America and the Caribbean. It is commonly found in Mexico, Honduras, Guatemala, and the West Indies, thriving in warm, tropical regions. The plant grows on rocky slopes, tree trunks, and cliffs, often in partial shade.

Plant Type and Habit

Unlike desert cacti, this species is a fast-growing epiphytic and lithophytic plant. It grows on other plants or surfaces without drawing nutrients from them. Instead, it absorbs moisture and nutrients from the air, similar to orchids. Its growth habit is sprawling and climbing, with long, flexible stems that can reach significant lengths. It is often used in hanging baskets or trained along trellises for support.

Plant Size

The stems can grow up to 20 feet (6 meters) or more in length, although they tend to stay more compact in cultivation. The stems are thin, typically measuring 0.4 to 0.6 inches (1-1.5 cm) in diameter, and segmented by distinct ribs. The cactus will spread and climb across its support in an ideal growing environment, creating a dramatic display.

Cactus Flowers

The flowers are the plant’s most striking feature. These blooms are large, measuring up to 10-12 inches (25-30 cm) across, with multiple layers of petals that create a star-like appearance. The flowers are white or pale yellow, with a delicate, waxy texture and a sweet, vanilla or orange blossom fragrance. The blooms are nocturnal, opening in the evening and typically closing by morning, making the cactus a symbol of fleeting beauty.

This flowering cactus typically blooms in late spring to early summer, with the exact timing varying depending on the growing conditions. The blooms last just one night, opening at dusk and wilting by dawn. The plant may produce several flowers in a single blooming season, each on a different night.

Fruit

After flowering, the Queen of the Night Cactus can produce small, round, juicy fruits. These fruits are usually red or orange when ripe and contain small, black seeds. In their native habitat, the fruits are also enjoyed by local wildlife, such as birds and small mammals.

Stem and Spines

The stems are thin, long, and ribbed, with a slightly spiny surface. Each rib is lined with small areoles that produce short, fine spines. The stems are green and fleshy, designed to store water, allowing the plant to survive periods of drought.

Hardiness

Selenicereus grandiflorus is hardy in USDA zones 10-12 and thrives in warm, tropical climates. The ideal temperature range is between 60°F and 85°F (15°C and 29°C). The plant is not frost-tolerant and should be kept indoors or protected from cold temperatures in regions with cooler winters. In colder climates, it is best grown as an indoor plant or in a greenhouse.

Uses

The Queen of the Night Cactus is primarily grown for its ornamental value. The large, night-blooming flowers and sprawling stems make it an excellent choice for hanging baskets, trellises, or climbing structures. It is often used in indoor plant collections or greenhouses where its dramatic blooms can be enjoyed. Due to its epiphytic nature, it also makes a great addition to living walls or mounted on tree bark.

Wildlife

In its native habitat, the large, fragrant flowers of this cactus attract moths and bats, which are its primary pollinators. The cactus’s night-blooming nature aligns with the activity patterns of these nocturnal creatures, which are drawn to its sweet scent. Additionally, the small fruits produced by the cactus are consumed by birds and small mammals, which help with seed dispersal.

Toxicity

The Queen of the Night Cactus is not known to cause harm to humans and pets, making it a safe choice for households with children or animals. However, it is always a good idea to keep the plant out of reach of curious pets, as ingesting large quantities of plant material could cause digestive upset.

Drought Tolerance

While Selenicereus grandiflorus prefers regular watering, it is somewhat drought-tolerant due to its ability to store water in its fleshy stems. It can survive short periods of dryness, but for optimal growth and blooming, it should be watered regularly during the growing season. 

Invasiveness

Selenicereus grandiflorus is not considered an invasive species. It does not spread aggressively, making it easy to manage in cultivation.

Benefits

The primary benefits of the Queen of the Night Cactus are its ornamental beauty and low-maintenance requirements. Its night-blooming flowers are a stunning spectacle, and its sprawling stems create a dramatic display in hanging baskets or on trellises.

Queen of the Night Cactus Care

Light

Soil

• Use a well-draining cactus or succulent mix. Adding perlite or orchid bark helps improve aeration.
• This cactus thrives in slightly acidic to neutral soil (pH 6.0-7.0) with good drainage to prevent root rot.

Watering

• Water thoroughly, but allow the soil to dry out slightly between waterings.
• During the growing season (spring and summer), keep the soil evenly moist but never soggy.
• Reduce watering in the winter when the plant is dormant.

Humidity

• The Queen of the Night prefers a warm, humid environment. Humidity around 50-60% is ideal. Mist the plant or place it near a humidifier if grown indoors.

Temperature

• The ideal temperature range is between 50°F to 85°F (10°C to 29°C). It is not frost-tolerant, so keep it indoors if temperatures drop below 50°F (10°C).

Fertilizer

• Feed with a balanced, diluted cactus fertilizer every 4-6 weeks during the growing season. Skip feeding in winter when the plant is dormant.

Pruning

• Minimal pruning is needed. Trim back overgrown or damaged stems to keep the plant neat and encourage fresh growth.

Propagation

• Easily propagated by stem cuttings. Allow cuttings to callous for a few days before planting them in well-draining soil.

Pests and Diseases

• Mealybugs, spider mites, and scale insects can occasionally affect the Queen of the Night Cactus. Treat infestations with insecticidal soap or neem oil.
• Ensure proper drainage to prevent root rot  from overwatering.

Blooming Care

• This cactus requires a cool, dry winter rest period to encourage blooming in the summer. To stimulate flowering, keep it in cooler conditions with reduced watering.