Blue Flame Cactus
Myrtillocactus geometrizans 'Blue Flame'
A fast-growing, heavily branching columnar cactus with powdery blue-green ribbed stems. Its many upright arms cluster like dancing flames, hence the name.
- Light
- Full sun to bright light
- Water
- Sparingly; dry out fully between
- Difficulty
- Easy
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Overview
Blue Flame Cactus is a vigorous, freely branching form of Myrtillocactus geometrizans, the blue candle cactus. It produces clusters of upright, ribbed, chalky blue-green columns that crowd together like a bundle of blue flames.
It is one of the faster-growing columnar cacti and branches far more readily than the standard species, quickly building a dramatic candelabra of stems. The waxy blue bloom on the stems is most intense in bright light.
Easy and tolerant, it makes both a bold landscape plant in mild climates and a striking container specimen.
How to identify it
- Upright, ribbed columnar stems with a chalky blue-green to powder-blue color
- Heavily branching and clustering, forming a candelabra of many flame-like arms
- Stems typically have 5-6 ribs lined with small, short spine clusters
- Fast-growing; can reach several feet tall in cultivation
- Mature plants bear small greenish-white flowers followed by small edible berry-like fruits
Care & growing
Light: Full sun to bright light; strong light deepens the blue color and keeps growth sturdy.
Water: Water sparingly, allowing the soil to dry fully between waterings; keep drier in winter.
Soil: Fast-draining cactus or succulent mix.
Temperature: Warm conditions; protect from frost, though it tolerates brief cool spells.
Feeding: Occasional dilute cactus fertilizer during active growth supports its fast pace.
Propagation: Easy from stem cuttings — let the cut callus well before planting in dry mix.
Habitat & origin
The parent species Myrtillocactus geometrizans is native to central and northern Mexico, growing in arid scrub and semi-desert on rocky, well-drained ground.
In its homeland it forms large branching shrubs. 'Blue Flame' is a cultivated, extra-branching selection grown worldwide as a landscape plant in frost-free regions and as a container cactus elsewhere.
Uses & benefits
Grown mainly as a bold ornamental for its blue color and sculptural branching form, used as a focal point in dry gardens and large containers.
The small fruits of the species (known as garambullo in Mexico) are edible and eaten fresh or dried where the plant grows wild. It is also sometimes used as a sturdy grafting stock for other cacti.
Frequently asked questions
Why is my Blue Flame turning greener instead of blue?
The blue is a waxy bloom that develops best in strong light. More sun typically restores the chalky blue-green color.
How fast does it grow?
It's one of the faster columnar cacti and branches readily, so with good light, warmth, and occasional feeding it can put on noticeable growth each season.
Can I grow it from a cutting?
Yes, easily. Cut a stem, let the wound callus over for several days to a week, then plant it in dry, gritty mix and water lightly once rooted.
Are the fruits edible?
Yes — the species' small purple berries, called garambullo, are edible and traditionally eaten in Mexico, though potted plants rarely fruit heavily.
Blue Flame Cactus guides
In-depth guides for identifying, growing, and caring for Blue Flame Cactus.
