Pilosocereus pachycladus

Blue Torch Cactus, Brazilian Blue Cactus, Blue Columnar Cactus, Facheiro Azul

Easy careTerrestrialNon-toxic20–100 cm

A tall columnar cactus from the caatinga of northeastern Brazil — one of the world's most arid biomes — where it reaches six metres on rocky hillsides and sand dunes. The stems are a distinctive powder-blue, intensifying in full sun, and are lined with golden-yellow spines from woolly areoles along each rib. Note: this plant is widely sold under the synonym Pilosocereus azureus (and the old invalid name Pilocereus azureus); all refer to the same species. As a seedling it grows slowly and suits a bright, open terrarium while small, but it is a columnar cactus by nature and will eventually outgrow any container setting.

Build a terrarium with this plant
Blue Torch Cactus image

Photo by B. Phalan·CC BY 4.0

Care

Prefers low humidity, direct light, with 10–40 °C, and reaches 100 cm at maturity.

Light

Direct light(preferred)Bright indirect

Humidity

Low (30–40%)(preferred)

Temperature

10°C25°C40°C
10°C – 40°C

Soil

Cactus mix(preferred)Well draining

Moisture

Dry(preferred)

Soil pH

6.1 – 7.3

Propagation

Cut a healthy stem section with a sterile blade and allow the cut end to callous in a dry, shaded spot for several days — this is essential to prevent rot. Once calloused, place upright in barely moist cactus mix and keep in bright indirect light until roots form, typically four to six weeks. Move gradually into direct sun once new growth begins.

Native range

Native to Brazil.

Native range

Appearance

Growth habit

Upright

Leaf shape

Needle

Leaf texture

SmoothSucculent

Frequently asked

Can Blue Torch Cactus grow in a closed terrarium?

Blue Torch Cactus prefers low (around 30–40%) humidity, which is below the level a closed terrarium typically maintains. It is better suited to an open terrarium or houseplant setup.

Does Blue Torch Cactus need drainage?

Yes. Blue Torch Cactus prefers a dry-leaning substrate and benefits from a drainage layer to prevent root rot.

What humidity does Blue Torch Cactus need?

Blue Torch Cactus does best in low (around 30–40%) humidity.

Is Blue Torch Cactus pet-safe?

Blue Torch Cactus is considered non-toxic to common household pets.

How tall does Blue Torch Cactus grow?

Blue Torch Cactus typically reaches 20–100 cm at maturity.

How do you propagate Blue Torch Cactus?

Blue Torch Cactus can be propagated by stem cuttings or seeds.

References

  1. 1

    Plants of the World Online — Pilosocereus pachycladus subsp. pachycladus

    https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:77224016-1
  2. 2

    Plants of the World Online — Pilosocereus azureus F.Ritter (synonym record)

    https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:196668-2
  3. 3
  4. 4

    Trex Plants — Care Diary: Pilosocereus azureus or pachycladus?

    https://trexplants.com/blog/care-diary-pilosocereus-azureus-pachycladus
  5. 5

    Plantophiles — Blue Torch Cactus Care Guide from A to Z

    https://plantophiles.com/plant-care/blue-torch-cactus/
  6. 6

    World of Succulents — Pilosocereus pachycladus (Blue Columnar Cactus)

    https://worldofsucculents.com/pilosocereus-pachycladus-blue-columnar-cactus/
  7. 7

    Succulent Alley — Pilosocereus azureus: Characteristics and Care

    https://succulentalley.com/pilosocereus-azureus/