Light
Full Sun
Requires full, direct sun; insufficient light causes thin, weak growth.
Reference image Jasminocereus thouarsii
Galapagos Jasmine Cactus
Overview
Jasminocereus thouarsii is a highly unique, tree-like succulent cactus endemic to the Galapagos Islands 1. It is commonly referred to as the Jasmine Cactus due to the sweet, jasmine-like scent emitted by its nocturnal white flowers.
Taxonomy and Naming
Originally described in the historical records, the genus Jasminocereus is now widely considered monotypic 2. The specific epithet honors the French botanist Abel Aubert du Petit-Thouars. Its growth form resembles a hybrid between branching trees and columnar cereoid cacti.
Distribution and Habitat
This species is strictly native to the Galapagos archipelago, thriving in seasonally dry tropical zones, rocky volcanic slopes, and arid coastal lava fields 1. It forms a key structural component of the island's low-altitude dry forests.
Appearance
Growing up to 7 meters tall, it develops a thick woody trunk with heavily ribbed, jointed branches. The olive-green branches are armed with dense clusters of yellowish to dark brown spines. Its tubular, nocturnal flowers are pale green to cream-white and open only for one night 2.
Cultivation
In cultivation, it requires conditions mimicking its dry volcanic habitat. It demands maximum sunlight and a highly porous, gritty mineral substrate. Overwatering must be strictly avoided as it is highly susceptible to rot.
Common Cultivation Mistakes
The most frequent mistakes are overwatering during winter and placing the plant in low-light conditions, which causes weak, stretched growth (etiolation) and root death.
Bibliography
References
Watering
12-30 Days
Water thoroughly only when the soil is completely dry. Keep dry in winter.
Soil
Well-draining, volcanic pumice and sand-rich cactus substrate
Extremely free-draining mix rich in pumice, lava rock, and coarse sand.
Safety
Pet Friendly
Armed with sharp spines; handle with thick gloves during repotting.
Difficulty
Moderate
Moderate; slow growth rate makes it manageable if dry conditions are met.
Native Habitat
Galapagos Islands, Ecuador
Endemic exclusively to the Galapagos Islands, this remarkable cactus occupies arid coastal plains and volcanic slopes, adapting perfectly to dry, harsh equatorial conditions.
Frequently Asked Questions
Can Jasminocereus thouarsii be grown indoors?
Yes, but you must place it in your **sunniest spot** (like a south-facing window) and ensure the soil is exceptionally well-draining.
How often should I water this cactus?
Water it about every 12 days in summer after the soil dries out completely. In winter, reduce watering to once every 30-40 days.
Is the Jasmine Cactus toxic to pets?
It is non-toxic chemically, but its **sharp, stiff spines** pose a physical injury hazard to pets and children.
What is the best soil mix?
Mix standard cactus soil with plenty of pumice, lava rock, and coarse sand to create an airy, fast-draining substrate.
Why is the base of my cactus turning yellow and soft?
This is usually a sign of root rot caused by **overwatering** or poor drainage. Stop watering immediately and check the roots.
How fast does Jasminocereus thouarsii grow?
It is a **very slow-growing** species in pots. Reaching a tree-like stature takes decades, even in its natural habitat.
When and how does it bloom?
Mature cacti produce fragrant, cream-white flowers that bloom at night during spring and summer, closing and fading by the next day.
Is it cold hardy?
No, it is sensitive to frost. Temperatures should **not drop below 8°C (46°F)**; it must be kept indoors during winter.
How often should I repot it?
Due to its slow growth, repotting every **3-4 years** is sufficient. Always use thick protective gloves when handling.
How do I keep the cactus growing straight?
Rotate the pot regularly to prevent the cactus from leaning towards the light, ensuring all sides receive equal sun exposure.