If you’re looking for a cactus that combines striking beauty with a touch of rarity, look no further. The Cereus forbesii – rare and beautiful is a true gem for any plant collection.
This columnar cactus, native to South America, stands out with its distinctive blue-green stems and dramatic nocturnal flowers. It’s a plant that rewards patience with a spectacular display, making it a prized possession for enthusiasts.
In this guide, we’ll cover everything you need to know to successfully grow and care for this stunning species.
Cereus forbesii – rare and beautiful
Often called the ‘Twisted Cereus’ or ‘Blue Candle’, this cactus is known for its unique form. Mature specimens develop multiple tall, ribbed columns that can take on a slight spiral. The most sought-after cultivar is arguably the ‘Ming Thing’, with its clustered, sculptural growth.
What truly defines it as rare and beautiful are its flowers. Large, fragrant white blossoms open only at night, often lasting just a single evening. Witnessing this bloom is a memorable event for any gardener.
Key Characteristics and Origins
Cereus forbesii hails from the arid regions of Bolivia, Argentina, and Paraguay. It has adapted to thrive in harsh, sunny environments with infrequent rainfall. Understanding it’s native habitat is the first step to replicating its ideal conditions at home.
Here are its main features:
- Stems: Blue-gray to blue-green in color, with 4 to 8 ribs. They can grow several feet tall over time.
- Spines: Short, sharp spines arranged along the ribs. They are typically a brown or gray color.
- Flowers: Nocturnal, funnel-shaped, and pure white with pinkish outer segments. They can be up to 6 inches long.
- Fruit: If pollinated, it produces a fleshy, red fruit that is edible, though not particularly flavorful.
Perfect Growing Conditions
Getting the environment right is crucial for a healthy cactus. The good news is, its needs are straightforward once you know them.
Light Requirements
This cactus loves bright, direct light. It needs at least 6 to 8 hours of strong sunlight daily to maintain its compact shape and blue hue. A south-facing window is ideal indoors. If moving outside for summer, acclimate it slowly to prevent sunburn.
Soil and Potting
Fast-draining soil is non-negotiable. A standard cactus and succulent mix works well, but you can improve drainage further by adding extra perlite or pumice. The pot must have excellent drainage holes. Terracotta pots are a great choice because they allow the soil to dry out more quickly.
Temperature and Humidity
Cereus forbesii prefers warm temperatures, between 70°F and 100°F during the growing season. It is not cold-hardy and should be kept above 50°F. Protect it from frost at all costs. Average household humidity is just fine; it does not require high humidity.
A Step-by-Step Care Guide
With the basics covered, let’s walk through the ongoing care routine. Consistency is key, but this plant is surprisingly low-maintenance.
Watering Your Cactus Correctly
The most common mistake is overwatering. This cactus is drought-tolerant. Here’s a simple schedule:
- During spring and summer (active growth), water deeply only when the soil is completely dry throughout.
- Soak the soil until water runs out the drainage holes, then let it drain fully.
- In fall and winter, reduce watering significantly. You may only need to water once a month or even less, depending on your home’s conditions.
When in doubt, it’s always safer to underwater. The plant can handle dry soil much better than soggy, wet roots.
Fertilizing for Growth and Blooms
Feeding is simple. Use a balanced, water-soluble fertilizer diluted to half-strength. A formula low in nitrogen is best, such as a 5-10-10.
- Fertilize only during the active growing season (spring to late summer).
- Apply it once every 4 to 6 weeks.
- Do not fertilize in the fall and winter when the plant is dormant.
This gentle feeding supports steady growth and can encourage those spectacular nighttime blooms.
Pruning and Maintenance
Pruning is rarely needed for shape, but you may need to remove offsets (pups) or manage size. Always use clean, sharp tools to make cuts. You can propagate the cuttings to grow new plants. Also, be careful when handling the cactus due to its sharp spines; wearing thick gloves is recommended.
Propagation Methods
Creating new plants from your Cereus forbesii is rewarding. The two main methods are by seed and by stem cuttings. Cuttings are faster and more reliable for home gardeners.
Here is how to propagate by stem cuttings:
- Choose a healthy, mature stem. Using a sterile knife, make a clean cut.
- Let the cutting callous over in a dry, shaded spot for about a week. This forms a seal to prevent rot.
- Plant the calloused end in a small pot filled with dry cactus mix. Do not water it yet.
- After about two weeks, give it a very light watering. Only water again once the soil is dry.
- Once you see signs of new growth, you can begin a regular, cautious watering schedule.
Common Problems and Solutions
Even with great care, issues can arise. Here’s how to identify and fix common problems.
Pests
Mealybugs and scale insects are the primary pests. Look for white cottony masses (mealybugs) or small brown bumps (scale) on the stems.
- Isolate the affected plant immediately.
- Remove pests with a cotton swab dipped in rubbing alcohol.
- For larger infestations, apply an insecticidal soap or neem oil solution.
Diseases
Root rot from overwatering is the biggest threat. Signs include a soft, mushy base or black spots on the stem. If caught early, you can save the plant:
- Unpot the cactus and remove all wet soil.
- Cut away any soft, rotten roots or stem tissue with a sterile tool.
- Let the plant dry completely for several days.
- Repot in fresh, dry cactus mix and do not water for at least a week.
Environmental Issues
Sunburn appears as pale, yellow, or brown scorched patches on the side facing the sun. Move the plant to a spot with slightly less intense light. Etiolation, or stretching, happens when the cactus doesn’t get enough light. The stem grows thin and pale. Provide more direct sunlight to prevent this.
FAQ About Cereus Forbesii
How fast does the twisted cereus grow?
It is a moderately slow grower, especially when young. With optimal light and care, you might see a few inches of growth per year. Patience is essential.
Will my blue candle cactus flower indoors?
Yes, it can flower indoors if it receives enough bright light and has reached maturity, which can take several years. A winter cool period can also help stimulate blooming.
Is the Cereus forbesii toxic to pets?
While not considered highly toxic, its spines are a physical hazard. It’s best to keep it out of reach of curious pets and children to avoid injury.
What’s the difference between Cereus forbesii and ‘Ming Thing’?
The ‘Ming Thing’ is a cultivated variety (cultivar) of Cereus forbesii. It is characterized by its much shorter, clustering, and intricately lumpy stems, making it look more like a sculpture than a typical columnar cactus.
Why is my cactus turning yellow?
Yellowing can be a sign of overwatering, poor drainage, or sometimes too much direct sun (sunburn). Check your watering habits and soil condition first, as overwatering is the most likely culprit.
Final Tips for Success
Caring for a Cereus forbesii is a lesson in minimalist gardening. Its needs are simple but specific. The most important factors are plenty of sun, very little water, and a pot that doesn’t hold moisture. Neglect is often better then over-attention with this species.
When you provide the right conditions, you’ll be rewarded with a resilient, architectural plant that adds a unique beauty to your space. And if you’re lucky enough to see its nocturnal flowers, you’ll understand exactly why it’s considered such a special and beutiful specimen. Its rarity in collections makes it a wonderful talking point and a testament to your gardening skills.