Edit blue columnar cactus Pilosocereus pachycladus

It is one of the most spectacular columnar tree-like cereus 1 to 10 (or more) m tall. It ramify at the base or develops a distinct trunk with dozens of erected glaucous (bluish-silver) branches. Its elegant habit (shape) makes it look like a miniature blue Saguaro. This is one of the bluest columnar cacti.
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 are usually located on one or more ribs near the apical part of the branches and produce thick, soft tufts of orange/white hair This area of the cactus is where the flowers pop out.
Cultivation and Propagation: It grows well, though slowly, but it possible to increase the speed of growth to some extent by providing 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 also blasting sun in summer. If grown indoor provide 4 to 6 hours, or more, direct morning or afternoon sun. It should be watered regularly in Summer and kept drier in Winter. It like pots with generous drain holes, 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 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.
Manteinance: Repot every two years.
Remarks: Do not use fatty products (like horticultural oil, neem oil, mineral oil, and insecticidal soaps) that can fade and ruin the characteristic blue colouration of the epidermis!
Propagation: Seeds or cuttings.