The trichocereus grandiflora [try-koh-KER-ee-us, gran-dih-FLOR-uh] belongs to the trichocereus or echinopsis cactus genus and is a member of the Cactaceae (cactus) family and refers to all the trichocereus hybrids.
The word “grandiflora” means a large flower referring to the flowering style of this cactus.
It is quite similar to Lobivia and Soehrensia and is included in those genera sometimes.
It was first discovered in Bolivia and Argentina, particularly in the Catamarca region as well as other regions of South America.
They’re now popular in low desert gardens as seen throughout Phoenix, Arizona.
Other botanical names for this cactus include:
- Lobivia grandiflora
- Lobivia grandiflorus
- Helianthocereus grandiflora
- Helianthocereus grandiflorus
- Helianthocereus huascha
- Trichocereus rowleyi
- Echinopsis huascha
- Echinopsis spachiana
The most common name for this plant is the torch cactus.
The golden torch and the silver torch cactus are some of their more famous versions.
Trichocereus Grandiflora Care
Size & Growth
Stems of trichocereus grandiflorus may grow in clusters potentially reaching a height of around 2’ feet tall at full maturity making it a columnar cactus.
The radial spines are around 1.5” inches long with a mature plant having around 12-18 ribs.
Flowering Trichocereus Grandiflorus Hybrid
Torch cactus has red flowers and may show slight variations in the shade since there are so many hybrid versions of this plant and many resemble the saguaro flower.
Some versions have white flowers which are usually between 6″ – 10” inches in size.
The tube of the cactus is quite hairy with areoles a whitish brown.
The flowers bloom at first light.
Light & Temperature
The torch cactus needs plenty of bright light during early spring all the way to late fall.
It’s a good idea to turn the plant around to ensure even sun exposure for all parts of the cactus.
Indirect sunlight with partial shade is best since the plant will not flourish under the full sun so a setting under a mesquite or palo verde tree would be perfect.
They require around 4-5 hours of sun every day for flowering.
Use some other material to protect a new plant from the sun.
In the winter, move it to an even more shaded space with less sunlight where the plant will go dormant and rest until the bloom season.
It is a very hardy plant and may even tolerate hard frost and freezing temperatures as low as 14° degrees Fahrenheit (-10° C).
It prefers a tropical to a temperate climate and may be grown indoors if these conditions are emulated.
The USDA hardiness zone for torch cactus is from 9-11.
Watering and Feeding
Peruviana Torch cactus should be watered deeply, keeping enough of an interval in between to allow the soil to dry slightly.
Make sure you water the plant frequently during the growing season, spring and summer.
Water near the base of the plant and avoid getting any on the plant column.
Getting water on the column or making the roots and soil too soggy may lead to plant diseases such as root rot.
If you’re growing your agave torch cactus in a pot, keep it well-drained.
During the fall and winter seasons, the cactus may go for long periods of time (up to 4 weeks) without water.
Ensure the dampness of the soil before applying fertilizer.
Ideally, you should fertilize your cactus once in spring and once in summer.
All-purpose, liquid fertilizer will suffice, but make sure you dilute it to half strength first.
There is no need to fertilize in fall and winter when growth is slow.
Soil & Transplanting
Trichocereus Grandiflorus require moist, well-drained soil which is not too wet.
Rocky soil with a little organic matter is best or plant using potting soil for cactus.
Torch Cactus Grooming and Maintenance
With the peruvian torch cactus, you won’t really need to prune much since it doesn’t grow too fast or spread too far.
Pruning is only required for elongated stems which have started to slough off and may be trailing on the ground.
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How to Propagate Torch Cactus?
The Tucson torch cactus may be propagated using seeds or cuttings.
- If you’re propagating by cuttings, obtain a 20-30 long piece from the top of the plant.
- Dry the end of the cutting (also known as callousing) by exposing it to direct sunlight.
- Cover the remaining length to protect it from sunburn.
- Leave the cutting like this for 1-2 days in a space in your home which receives plenty of sunlight.
- Store your cuttings for a while, but surface mold is likely to appear after some time.
- Choose a well-drained potting mix (do NOT go for houseplant soil) – a mix of dry soil, perlite and sand is a good choice.
- Stick the cutting around 3″ – 5” inches deep in the soil.
- Don’t water the soil if it is already moist since this may lead to overwatering.
It will take a few months for roots to form after which the pot is ready to be moved under direct sunlight.
Torch Cactus Pest or Disease Problems
Your cactus may be susceptible to root rot if it is overwatered.
In these cases, use the appropriate insecticide (try neem oil) to revive your cactus.
Is The Trichocereus Grandiflorus Plant Toxic Or Poisonous?
The torch cacti are considered to be mildly toxic for animals and humans and eating them may cause irritation in the stomach and mouth and may even make you throw up.
Suggested Trichocereus Grandiflora Uses
Although the succulent Cleistocactus strausii mostly has ornamental uses, research indicates the trichocereus grandiflorus hybrid’s flowers contain mescaline which has psychedelic properties.