Accepted Name and Synonyms: In modern literature, many sources integrate T. peruvianus within Trichocereus macrogonus sensu lato (Echinopsis macrogona), with two main varieties: var. macrogonus and var. pachanoi. In horticulture, "peruvianus" continues to be used for more bluish and spiny forms.

Origin and Distribution: Andes regions of Peru, Ecuador, and Bolivia. It has been widely introduced and cultivated in other areas.

Habitat and Altitude: Andean slopes and valleys, rocky, well-drained soils, with a significant daily temperature range. Commonly found at elevations between 2,000–3,000 m above sea level.

Habit and Size: Upright, branched column; in cultivation, it can reach 2.5–5 m (exceptionally taller) and 6–15 cm in diameter per stem.

Ribs: Typically 6–8 (sometimes 5–9), well-defined.

Areoles and Spines: Areoles spaced >2.5 cm apart; spines vary depending on environment and genetics. In "peruvianus" forms, they tend to be longer and more robust than in "pachanoi."

Epidermis: Green to blue-green, with a more noticeable waxy layer (pruina) in "peruvianus" forms.

Flowering: Large, nocturnal flowers (up to ~20–21 cm), highly fragrant; inner segments typically white, with outer segments in greenish/yellowish tones. Flowers form near the apex.

Fruit and Seed: Elongated fruits that dehisce upon ripening, with light pulp and shiny black seeds.

Light: Full sun for adults to achieve compact epidermis and bluish color; in seedlings and transplants, begin with filtered light and gradually increase to avoid burns.

Temperature: Optimal growth between 18–32 °C. A cool, dry winter dormancy enhances flowering.

Cold Tolerance: In very dry soil for brief periods, it can withstand around -4 to -6 °C. Horticultural recommendation: cultivation in soil in USDA zones 9b–11; possible in 8b with protection, dry soil, and extreme drainage.

Wind/Rain: Avoid exposure to persistent rains during cold weather. In humid climates, provide seasonal coverage or grow in containers.

Principle: Quick drainage, aeration, and a mineral-dominant structure.

Recommended Mix (for pots): 60–80% inert mineral (pumice/tezontle, 3–6 mm gravel, washed coarse sand, perlite) + 20–40% stable organic matter (well-washed blonde peat or coconut fiber; very mature, screened compost). Adding 5–10% zeolite or akadama improves cation exchange capacity (CEC) and stability.

pH: Slightly acidic to neutral, 6.0–7.2. In soft water, a pinch of dolomite provides Ca/Mg and buffers the pH.

Container: Deep and heavy (clay or thick-walled plastic) with a large drainage hole and a basal layer of gravel.

Garden Soil: Raised beds, mixing soil with 40–60% aggregates. Avoid compact clays and waterlogged areas.

Spring–Summer (Active): Water thoroughly when the substrate is completely dry throughout the profile. In heat, water cycles of 7–14 days depending on pot size and ventilation. Better to water deeply and infrequently than frequently with small amounts.

Autumn: Gradually reduce watering to induce dormancy.

Winter: Keep dry if it's cold. In a warmed greenhouse (≥10–12 °C), very light and spaced watering to avoid excessive wrinkling.

Water Quality: Preferably soft or remineralized osmosis water (Ca/Mg). Avoid wetting the neck in cold conditions.

Adjustment Signals: Slight longitudinal wrinkles = time to water; soft/watery tissue = excess; pale, elongated growth = lack of light.

Schedule: During growth, every 3–4 weeks with a balanced fertilizer, low in N and high in K (e.g., 3–7–7 or 5–10–10) including micronutrients.

Dosage: Moderate concentrations for cacti; avoid quickly available ureas that soften tissue.

Calcium and Magnesium: Regular supply (dolomite or Ca/Mg in fertigation) to maintain firm epidermis and proper spination.

Organic Matter: Minimum and very stable. Excess promotes rot.

Age of Flowering: From seed, typically at 5–8 years with good management; from mature cuttings, in 2–4 years.

Induction: Cool and dry dormancy in winter, good sunlight, and thermal amplitude in spring.

Pollination: Many lines are self-incompatible, responding better to cross-pollination between clones for good seed quality.

Pruning and Height Control: End of spring–summer. Disinfect, cut straight, and allow to heal. The apical segment can be used as a cutting; the base will regrow from dormant areoles.

Supports: Recommended for tall specimens in containers.

Transplanting: Every 2–3 years or when the root ball fills the pot. Do not water 5–7 days after transplanting to allow micro-wounds to heal.

Cotton and Scale Insects: Check areoles and neck. Control with point application of isopropyl alcohol, potassium soaps, or horticultural oils; for infestations, use specific systemic treatments according to local regulations.

Red Spider Mites: Cause speckling and discoloration; increase ventilation and apply selective acaricides if necessary.

Slugs/Snails: Damage young epidermis; use physical barriers, traps, and hygienic management.

Rot (Fungal/Bacterial): Avoid with drainage, correct watering, and dry dormancy in cold. For lesions, dry the affected tissue until healthy and dust with sulfur or copper; isolate the plant.

Physiopathies: Sunburn from sudden light changes; edema from cold watering; etiolation from lack of sun.

Peruvianus (horticultural sense): More glaucous-blue epidermis, well-defined ribs, and longer spines, with areoles somewhat more spaced apart.

Pachanoi: More intense green color, short or almost absent spines in shaded cultivation, softly rounded ribs.

Important: Spination is highly variable with the environment; there are intergradations and hybrids. For serious collections, maintain traceability of origin/clon.

Outdoor (dry/mild zones): Full sun, raised bed, and controlled watering. Excellent as a living defensive hedge and architectural specimen.

Bright Indoor: Only viable near SE/S windows. Rotate the pot for straight growth; watch for mites.

Cold Greenhouse: Ideal for dry dormancy in winter and to prevent rain. Ventilate to minimize fungi.

Cracking after watering: Very long intervals followed by excessive watering; apply more frequent and moderate watering during the season.

Soft tissue in winter: Excess water in cold conditions. Suspend watering, move to a warm, dry location.

Sunburn: Acclimate over 2–3 weeks when transitioning from shade to sunlight.

Not flowering: Lack of winter dormancy, excess nitrogen, or low radiation. Adjust management and photoperiod.

February–March: End of dormancy, first light watering, pest check. Transplant if minimums rise.

April–June: Strong growth: sun, thorough watering, monthly fertilization.

July–August: Full heat: maintain drying cycles; watch for thermal stress in black pots.

September–October: Reduce watering; last potassium-rich fertilization.

November–January: Dry dormancy; protect from frost and persistent rains.

Prefer specimens with a firm epidermis, free from soft spots or recent wounds.

For collection materials, request traceability of clone/seed and photos of the mother plant.

Well-rooted plants established before shipping reduce post-transport losses.

Exposure: Full sun (acclimate).

Watering: Deep and spaced; dry in winter.

Substrate: 60–80% mineral, pH 6.0–7.2.

Fertilization: Low in N, high in K, monthly during the season.

Cold: Briefly down to ~-5 °C in dry conditions; preferable to protect.

Propagation: By seed and cutting; grafting optional.