Blue Torch Cactus
Flowers are not the only plants that bring color to the garden. Some plants, like the Blue Torch Cactus (Pilosocereus azureus), have unique colored-stems or trunks.
This cactus has an unassuming and tidy columnar shape, growing tall and upright, but has unusual colors: blue stems and contrasting gold spines. The blooms are showy with big, magnificent white flowers.
Blue is one of the most unusual colors among plants. The Blue Torch Cactus will certainly create a sense of awe, especially among your visitors who have never seen a blue cactus before.
Botanical name: Pilosocereus azureus
Other names: Blue Columnar Cactus, Blue Cactus
Blue Torch Cactus (Pilosocereus azureus) among other desert plants at our nursery
TABLE OF CONTENTS
Blue Torch Cactus Appearance
Blue torch cactus usually reaches 10 to 20 feet tall, up to 30 feet in its native environment. Grows neatly upright.
The blue stem turns bluer as it matures and when it gets sufficient light. Otherwise, the plant will be on the greener side.
The spines along the ribs are yellow/ gold. White, showy flowers bloom at night.
Blue Torch Cactus Landscaping Tips
Blue Torch Cactus is one of our most heat tolerant plants, withstanding intense sunlight better than the average cactus here in the Palm Springs area. Make sure you water well during summer.
When choosing a location for planting, keep in mind that the spines are very sharp, and that this plant grows very tall.
This plant has an upward-growing habit, but some stems can curve. If a more upright shape is desired, prune in late winter or early spring.
Blue Torch Cactus Origin
Semi-tropical region in Brazil
Blue Torch Cactus Care
Detailed look at Blue Torch Cactus
Soil: Loose, well draining soil that is moderately fertile. Cactus or succulent soil mixes work well.
Temperature: Can withstand temperatures down to 35 degrees for a brief period of time.
Water: Compared to other cacti, Blue Torch Cactus is not sensitive to humidity. Regular watering during hot summer months (slightly more than the average cactus). Occasional watering during cool winter months, when it's dormant. Make sure soil is completely dry in between waterings.
Sun: Full sun
Blue Torch Cactus Problems
Pests: Blue Torch Cactus has minimal pests, which are usually scales and mealybugs.
To remove scales, pick them off or use horticultural oil or insecticidal soap. Horticultural oil will kill both crawlers and adults with direct contact. Insecticidal soap is better used to target only the crawlers.
For mealybugs, apply rubbing alcohol directly on the bugs using cotton swabs or use insecticidal soap. Whenever using any kind of pesticide, be aware that it can damage the plant if the temperatures are in the 80s or above.
Fungal diseases from root rot, dry rot, and harsh weather conditions.
Signs of overwatering: Yellowing, drooping, squishy texture (especially an the bottom of the cactus)
Signs of too little water: Shriveling, drying skin, fading color
Signs of too much sun: Burning, scarring
Signs of too little sun: Etiolation, discoloring (initial sign is when it turns green)
Blue Torch Cactus Propagation
Take stem cuttings to propagate your Blue Torch Cactus. Using a blade, cut the very top part of the plant, allow it to callous, and plant it into soil.
Once mature, the cactus will grow fruit. You can take the seeds and directly plant them.
FAQ
How much does Blue Torch Cactus cost?
At our nursery, Blue Torch Cactus costs $15 for a 1 gallon pot, $55 for a 5 gallon pot, and $150 for a 15 gallon pot.
Prices are subject to change. Please contact us for the most up-to-date information on pricing. We may have larger sizes available. We provide installation services locally at a separate cost.
Why is my Blue Torch Cactus turning green?
It is not getting enough sunlight.
Where does the Blue Torch Cactus get its color from?
Blue tones protect the cactus from the sun. When the Blue Torch doesn't get much sunlight, it'll be green. However, when it gets a lot of light, it will create a creamy wax on the surface that acts as sunscreen, and gives off the blue color.
How fast does Blue Torch Cactus grow?
In the Palm Springs area, you can expect it to grow about 1 to 1.5 feet a year until it reaches maturity.
How tall does Blue Torch Cactus get?
It usually reaches 10 to 20 feet, and up to 30 feet in its native environment.
Summary
| SIZE (H X W) | 10-20 feet X 2 feet |
|---|---|
| FLOWER COLOR | White/Yellow |
| FLOWER SEASON | Spring to Early Summer |
| EXPOSURE | Full Sun |
| WATER | Low |
| GROWTH RATE | Fast |
| HARDINESS | 35º F, USDA Zone 10 |
| PRUNING | None |