Light
Filtered Sun
Filtered sunlight or light shade is ideal; protect from intense, direct midday summer sun.
Reference image Cereus kreggii
Night-blooming Cereus
Overview
Cereus kreggii (commonly accepted as Peniocereus greggii), is one of the most remarkable and enigmatic species of the Cactaceae family. For most of the year, it resembles a dry, lifeless stick, but during midsummer nights, it produces magnificent, intensely fragrant flowers 1.
Taxonomy and Naming
Often classified under the genus Peniocereus, this species has historically been referred to as Cereus greggii or its orthographic variant Cereus kreggii 2. It is widely known by the common name 'Queen of the Night' or 'Desert Night-blooming Cereus'.
Distribution and Habitat
Native to the arid regions of North America, it is primarily found in Arizona, Texas, and Northern Mexico, within the Sonoran and Chihuahuan deserts. It typically grows under the canopy of desert nurse plants, such as creosote bushes, which shield it from extreme conditions 1.
Appearance
The plant develops an enormous, starch-storing tuberous root system underground, which can weigh up to 70 kg. The above-ground stems are slender, grayish-green, ribbed, and almost woody. Its spectacular white flowers are funnel-shaped, up to 20 cm in diameter, opening for just one night and fading by morning 2.
Culture and Care
In cultivation, it requires highly porous, sandy, and pumice-rich soil. Overwatering can rapidly rot the large subterranean root system. During winter, watering should be suspended completely, and the plant must be kept in a cool, dry place to induce dormancy 1.
Common Care Mistakes
The most frequent errors include exposing the young stems to harsh direct midday sun and using heavy, clay-rich soils that retain moisture. Lack of a cool, dry winter rest will also prevent the plant from flowering.
Bibliography
References
Watering
10-30 Days
Allow the potting medium to dry out completely between waterings; suspend watering in winter.
Soil
Well-draining, coarse sand, pumice, and cactus potting mix
Requires an extremely gritty, free-draining substrate rich in pumice, gravel, and sand.
Safety
Pet Friendly
The stems have small spines that can prick, but the plant is non-toxic and safe for pets.
Difficulty
Moderate
Moderate care level due to strict watering requirements and susceptibility to root rot.
Native Habitat
North America (Southwestern USA, Northern Mexico)
Found in the Chihuahuan and Sonoran deserts, growing cryptically under the protection of desert shrubs.
Frequently Asked Questions
Can Cereus kreggii be grown indoors?
Yes, but it must be kept in a deep, highly-drained pot placed by a sunny, well-ventilated window.
When do the flowers bloom and how long do they last?
The flowers bloom in midsummer at dusk, releasing a strong fragrance, and wither by sunrise the next morning.
How often should it be watered?
Water only when the soil is completely dry in summer (about every 10 days) and withhold watering almost entirely in winter.
What kind of soil does it need?
It requires a specialized cactus mix with plenty of pumice, sand, and volcanic rock to prevent root rot.
Is it frost tolerant in winter?
It can tolerate light frosts down to -2°C if kept completely dry, but potted specimens should be protected from freezing.
Is it toxic to pets?
No, it is non-toxic and safe for pets. However, care should be taken regarding its small spines.
How fast does it grow?
Above-ground growth is quite slow, as the plant directs most of its energy into expanding its underground tuberous root.
Why is my plant not blooming?
Keeping the plant warm during winter or continuing to water it during dormancy prevents flower bud initiation.
When should it be repotted?
Due to its massive root system, it should be repotted every 3-4 years in early spring using a deep container.
Why are the stems wrinkling?
Wrinkling can be caused by severe dehydration or, conversely, root rot from overwatering. Check the roots immediately.