Scientific Name: Pilosocereus pachycladus F.Ritter
Common Name(s): Blue Columnar Cactus
- Pilosocereus pachycladus
- subsp. Pachycladus,
- Pilosocereus atroflavispinus,
- Pilosocereus azureus,
- Pilosocereus cenepequei,
- Pilosocereus cyaneus,
- Pilosocereus oreus,
- Pilosocereus schoebelii,
- Pilosocereus superbus,
- Pseudopilocereus atroflavispinus,
- Pseudopilocereus azureus,
- Pseudopilocereus oreus,
- Pseudopilocereus pachycladus,
- Pseudopilocereus superbus
- Family: Cactaceae
- Subfamily: Cactoideae
- Tribe: Cereeae
- Genus: Pilosocereus
Description of Cacti of the Genus Pilosocereus
Pilosocereus is a genus of thorny plants with about 50 species of cacti that have spread from Mexico and the Caribbean to northern South America. Basically, these are large columnar individuals. The genus Pilosocereus was known as Pilocereus until 1954.
It was renamed due to an inconsistency found in the rules of botanical nomenclature. Translated from Latin, the name of the genus means “felt cereus”. The name is given because of the hairy areoles on its stems.
Many species in this genus have showy blue stems, but may also be green. Plants are shrubby or large, tree-like. These desert crops grow fairly quickly, often adding 30 to 60 cm per year.
They can grow up to 3-9 meters in height, because of this they are called cacti-trees in their homeland.
At home, the plant will not grow to this size, but if given a large pot, fertilized frequently, and kept in direct sunlight for most of the summer, the cactus can grow up to 1.5 to 3 meters tall.
“Pilosocereus pachycladus and is a shrubby to tree-like species originating from northeastern Brazil where the wet season lasts from November to January. The investigated specimen was tree-like. The well-defined, erect trunk reached a total height of 5 m and 12 cm in diameter at the stem base. The branches originated 1.5 m aboveground and attained diameters of up to 11 cm”
Stem: Turquoise/ sky blue or light blue-green. Branches 5,5-11 cm in diameter.
Ribs: 5-19 about, straight, with traverse, folds visible only at the stem apexes, 15-35 mm wide and with12-24 mm deep furrows,
Pseudocephalium: As Pilosocereus cacti age, they produce what is called a ‘pseudocephalium’, but in Pilosocereus pachycladus the fertile portion is often slightly differentiated from normal vegetative parts.
The floriferous areole is usually located on one or more ribs near the apical part of the branches and produces thick, soft tufts of orange/white hair (sort of like that seen in ‘old man cacti’ Cephalocereus senilis). This area of the cactus is where the flowers pop out.
Areoles: 3-10 mm in diameter, 2-12 mm apart with white to grey felt and long white bristles. The areoles that bear flowers are very hairy.
Spines: Translucent with a yellow hue turning grey as they get old.
Central spines: 1 to 12, straight, directed upwards 1-30 mm long.
Radial spines: 8 to 18 addressed against the ribs, 5-15 mm long.
Flowers: More or less funnel-shaped whitish with greenish or reddish outer segments but quite variable in size, 4-7 cm long, 22-45 mm in diameter. The flower buds are obtuse or acute dark magenta.
Blooming season (Europe) The flowers open at night in summer and continue the day after; (in its habitat it flowers in October and fruits in January) Flowers are seen only in large, mature specimens at least 1 m tall.
Fruit: Reddish purple, flattened globular, with dry flower remnants; the pulp is magenta or red and the fruit opens at maturity by lateral splits.
Seeds: Shiny black.
Chromosome number: 2n = 22/44
Cultivation and Propagation of Pilosocereus Pachycladus
It grows well, though slowly, but it is possible to increase the speed of growth to some extent by providing an adequate amount of water, warmth, and an all-purpose liquid fertilizer diluted half strength during the active growing season, but it’s susceptible to rotting if too wet.
It likes a sunny position and also blasting the sun in summer. If grown indoors provide 4 to 6 hours, or more, of direct morning or afternoon sun.
It should be watered regularly in Summer and kept drier in Winter.
It likes pots with generous drain holes that need a very porous, slightly acidic potting medium (add pumice, vulcanite, and perlite).
It can be grown outdoors in frost-free climates, needs anyway to be kept above 12 °C and dry in winter. But it can tolerate temperatures down to 5° C (or even 0° C) for very short periods if very dry and ventilated.
Maintenance: Repot every two years.
Propagation: Seeds or cuttings.
How to Grow and Care for Pilosocereus Pachycladus
Like most cacti, Cereus are fairly low-maintenance and hardy. Make sure they receive enough water without becoming waterlogged, especially during the summer, and fertilize them for best results. If the roots have become black or overly soft, the cactus could be experiencing root rot. Cut away the affected parts and replant. Most gardeners interested in cacti should be able to cultivate these without much problem.
It may become necessary to repot your Cereus if it outgrows its container. If so, make sure the soil is dry, and then remove the pot. Knock away old soil, prune away any rotted or dead roots, then replace it in a new pot and backfill it with new soil. Make sure not to overwater cacti planted in new pots, as this can lead to root rot. It should be left dry for about a week and then watered lightly.
These cacti propagate quite easily from cuttings. Simply sever a branch and replant in moist, well-drained soil.
How does Pilosocereus bloom?
Like many other cacti related to Cereus, Pilosocereus produces large, strongly scented, funnel-shaped flowers in summer that open at night and remain open for less than 24 hours.
The flowers are tubular, and the flower tubes and unopened buds are often blue. Parts of the perianth are often white or pinkish-white, with many stamens.
“Bats produce natural pollination.”
After flowering, fleshy fruits containing seeds and pulp are tied. Despite their large size, Pilosocereus are commonly grown as houseplants in tropical regions due to their aesthetic beauty.
How to grow Pilozocereus cactus at home
Most Pilosocereus grow in areas with a dry season from November to May and a wet season from May to October.
As a house plants, they are not fussy and do not create problems in care. But some features must be taken into account.
Soil: For best maintenance results, use a sandy soil mix that provides reasonably good drainage. You can purchase succulent substrate from your local garden center or form your own soil mix.
To do this, just take 1 part universal potting soil, 2 parts pumice or perlite, 1 part sand or gravel and mix well.
Check to see if water is running straight through the medium before planting Pilosocereus.
If water does not flow well through the soil mix, you can always add more pumice, perlite, sand, or gravel. The goal is to make it sandy enough to circulate air and drain water, but still, have enough earth to support your cactus.
Pilosocereus prefers a slightly acidic pH (6.1-7.3). Add coffee grounds to the soil from time to time to keep your plant growing well.
Lighting: Pilosocereus loves the sun. In bright light, it becomes more bluish, and the spikes take on a golden-orange color.
However, if you are raising your pet indoors, look for south or west-facing window to make the most of the sun. If you don’t have a south or west-facing window, place one in the sunniest part of your home.
For maximum growth, members of the genus Pilosocereus should be exposed to direct sunlight for at least 6 hours daily. Without this, growth will be severely limited and the plant may become susceptible to disease.
Temperature: Pilosocereus cacti thrive in high temperatures and tropical and arid climates. It can withstand heat up to 30°C and cool down to -1°C. In winter, it should be protected from frost. For rapid growth, the temperature at night should be low, around 15 °C. Remember that when the temperature drops, Pilosocereus hibernates.
Humidity: Pilosocereus can be considered a semi-tropical crop as it grows in abundance in the Caribbean and South America. Humidity in the natural environment ranges from 40% to 70%. Good air circulation makes the plant resistant to humid environments. However, Pilosocereus tolerate periods of drought well.
How often should Pilosocereus be watered?
Plants in this genus are not unique in their preference for moisture and should be watered just like all other succulents. We recommend watering Pilosocereus about once a week for most of the year. Before watering it, be sure to test the soil first. This helps prevent excessive soil moisture and prevent root rot. In winter, it is necessary to stop moisturizing or give him water once a month. Overwatering in winter is the most common cause of root rot.
Pilosocereus cacti grow fast, but fertilizer can help them grow even faster. Top dressing in the summer is the best time. Use a water-soluble balanced fertilizer and apply at least once a month. If you’re applying liquid fertilizer, make sure you dilute it by half so it doesn’t burn the roots of your Pilosocereus. If the package says to use one tablespoon per liter of water, use half a tablespoon instead. Fertilization should be stopped in autumn and winter.
Pilosocereus grow quickly and need to be transplanted every 2 years into a larger pot if you want to grow a large tree. It can be kept small if kept in a small pot and not repotted. Plants have an extensive fibrous root system. They do not have a tap root, so they do not penetrate deep into the ground and there is no need for a deep pot.