TRICHOCEREUS PACHANOI: Complete Guide. Everything You Need to Know
Trichocereus pachanoi: Complete Guide to Cultivation, Identification, and Professional Management
Trichocereus pachanoi (syn. Echinopsis pachanoi, currently treated by many authors as Trichocereus macrogonus var. pachanoi) is a fast-growing Andean columnar cactus, highly valued in gardening and collecting for its architectural form, hardiness, and great adaptability. At TRICHOLAND we work with selected lines for professional production due to their vigor, low spination, and high tolerance to variable conditions.
This technical guide compiles everything you need to successfully cultivate it at an advanced amateur or nursery level: taxonomy and identification, substrates, irrigation, nutrition, light and climate, propagation, plant health, annual calendar, and troubleshooting.
Taxonomy and Names of Trichocereus pachanoi
Genus: Trichocereus (frequently segregated from Echinopsis according to contemporary morphological and genetic criteria).
Commonly accepted name: Trichocereus macrogonus var. pachanoi.
Synonyms: Trichocereus pachanoi, Echinopsis pachanoi, formerly Cereus pachanoi.
Common names: San Pedro (ornamental/gardening use), among other Andean regional names.
Origin and Natural Habitat of Trichocereus pachanoi
Native to Ecuador, Peru, and Colombia; widely cultivated throughout South America and beyond.
Altitude: typically between 2,000 and 3,000 m a.s.l., on well-drained slopes, rocky soils, and climates with marked dry/wet seasons.
Description and Field Identification of Trichocereus pachanoi
Form: column branched from the base; 3–6 m tall in mature cultivation; exceptional specimens documented up to ~12 m.
Stems: light to dark green, sometimes glaucous; 6–15 cm in diameter.
Ribs: usually 6–8, well defined.
Areoles: whitish, spaced ~2 cm apart; 0–7 short spines (up to ~2 cm), frequently nearly spineless in selected cultivars.
Flowering: large, white, very fragrant, nocturnal flowers; 19–24 cm long and up to ~20 cm in diameter; perianth with dark hairs on the floral tube. They open at night and may last ~2 days.
Fruit: dark green, oblong, approx. 3 cm diameter × 5–6 cm long; opens when ripe showing white pulp with numerous seeds.
Professional Cultivation Requirements for Trichocereus pachanoi
Climate and Exposure for Optimal Cultivation
Light: full sun once acclimated. Young or newly transplanted plants benefit from partial shade (40–50% shade cloth) for 2–4 weeks. Indoors/greenhouse target PPFD 250–400 µmol/m²/s for sustained growth; 400–600 for rapid growth with adequate ventilation and nutrition.
Temperature: optimal 18–30 °C. Enters dormancy below 10–12 °C.
Cold/Frost: tolerates brief drops below zero if dry. Conservative recommendation: safe cultivation in USDA zones 9a–11. With expert management and very well-draining substrate, there are reports of occasional tolerance to −3 to −6 °C (exceptionally more) in mature, fully dry specimens; avoid prolonged exposure or frosts with wet soil.
Wind: tolerates wind; stake in exposed sites until base thickens.
Recommended Professional Substrate for Trichocereus pachanoi
Seek fast drainage, high root aeration, and moderate retention. Recommended mix for pot or container:
50–70% mineral fraction: pumice/pozzolana (2–8 mm), volcanic gravel, or coarse washed sand. Pumice provides aeration and moderate retention.
30–50% organic fraction: fibrous blond peat or medium-fiber coconut + 10–20% well-sieved mature compost.
Amendments:
Carbonate/dolomite: 2–4 g/L if acidic peat is used (provides Ca/Mg and stabilizes pH).
Mycorrhizae/Trichoderma: useful in nursery for vigor and root health.
Target pH: 5.8–6.5 (wide tolerance ~5.5–7.2). Avoid saline or very compact substrates.
Proper Irrigation for Trichocereus pachanoi
Spring–Summer: deep and spaced watering, allowing 50–80% of substrate volume to dry between irrigations. In pots, usually equivalent to 1 watering every 5–10 days depending on temperature, pot size, wind, and radiation.
Autumn: progressively space out. Replace with light watering if still warm.
Winter: in cold climates, keep practically dry to avoid rot. In frost-free areas, very occasional light watering on mild days.
Water quality: low EC (15 °C): supply 50–100 ppm N per application, every 2–4 irrigations, with cactus fertilizer low in N and high in K (e.g., 3-5-7 to 4-7-8) and chelated micronutrients (Fe, Mn, Zn). Avoid urea as main N source.
End of summer: reduce N and prioritize K/Si to mature tissues and improve cold tolerance.
Salt leaching: every 6–8 weeks, irrigate with abundant clear water to prevent accumulation.
Signs of excess: soft tissues, loss of well-defined ribs, etiolation. Adjust dose or frequency.
Pots, Transplants, and Structure for Professional Cultivation
Container: deep with multiple holes. Slotted pots or air-pots highly recommended for lateral aeration.
Transplant: every 2–3 years or when root ball occupies 80–90% of volume. Best time: late spring–summer with stable temperatures.
Staking: fiberglass cane or rod; elastic ties to avoid strangulation.
Professional Propagation of Trichocereus pachanoi
By Cutting (Preferred Nursery Method)
Selection and cutting: choose healthy segments (20–40 cm). Clean cuts with disinfected tool, slightly beveled to drain.
Curing: allow to callus vertically, in bright shade with ventilation for 10–21 days (until dry callus forms). In humid climates, dust sulfur or cinnamon on the cut.
Rooting: place cutting on very mineral and barely moist substrate; do not bury excessively. Optional: powder AIB hormone on callus.
Conditions: 22–28 °C substrate temperature, bright light without direct sun. First moderate watering when visible root emission occurs (2–3 cm) or after 2–4 weeks in stable warmth.
By Seed
Substrate: very fine and sterile (50% fine silica sand + 50% sieved peat/coco). Disinfect by microwave/oven.
Sowing: surface, uncovered or with very fine sand layer. High humidity (80–90%) under cover/dome, diffuse light.
Temperature: 22–28 °C. Typical germination in 7–21 days.
Handling: progressively ventilate from 2–3 weeks to avoid fungi. First very diluted fertilization at one month.
Grafting (Advanced)
Useful to accelerate seedling growth or rescue valuable material. Recommended rootstocks: Myrtillocactus geometrizans, Trichocereus spachianus, other vigorous Trichocereus.
Pruning, Shaping, and Form Management of Trichocereus pachanoi
Tip pruning to induce branching at desired height.
Cut health: perform in dry, warm weather; dust sulfur; keep dry until callus forms.
Height control: in gardening, segment and replant to renew aged bases.
Common Pests and Diseases in Trichocereus pachanoi
Common Pests
Mealybugs (aerial and root): check areoles and collar. Control: cleaning with 70% isopropyl alcohol, potassium soap, and horticultural oil in rotation; for roots, soak root ball in soapy solution and transplant to clean substrate. In production, consider biological control (Cryptolaemus, Anagyrus) and systemic baits according to local regulations.
Red spider mite: during heat waves and low RH. Prevention with morning showers outdoors (summer only) and light oils; releases of Phytoseiulus in greenhouse.
Scale insects and thrips: periodic inspection, oils, and authorized growth regulators.
Slugs/snails: physical barriers and perimeter baits.
Common Diseases
Soft rots (bacterial) and fungal (collar/root) due to excess moisture and cold. Management: aggressive sanitation to healthy tissue, tool disinfection, sulfur/copper on cut and dry curing. Adjust irrigation and ventilation.
Anthracnose/Spots: improve aeration; preventive contact fungicides where authorized. Avoid nocturnal wetting of stem.
Iron chlorosis: typical of hard water/high pH. Correct irrigation pH and apply Fe-EDDHA.
Common Problems and Solutions in Trichocereus pachanoi Cultivation
Etiolation (pale and narrow growth): lack of light or excess N. Gradually increase irradiance and balance fertilization.
Sunburn: corky brown spots after sudden exposure to full sun. Acclimate 2–3 weeks with shade cloth.
Edema: blisters/cork from heavy watering with cold substrate. Water during warm hours and improve drainage.
Longitudinal cracking: watering spikes after prolonged drought. Stabilize frequency and volume.
Annual Cultivation Calendar for Trichocereus pachanoi (Northern Hemisphere, adapt 6 months for Southern Hemisphere)
Mar–Apr: start watering; first mild fertilizations; transplanting.
May–Aug: peak growth. Deep and regular watering; complete nutrition; weekly phytosanitary checks. Shade young plants during heat waves.
Sep: reduce N; check structure before storms.
Oct–Nov: space watering; prepare dry overwintering; protect from cold rains.
Dec–Feb: dormancy; minimal or no watering in cold; monitor root mealybugs.
Landscape Use and Design with Trichocereus pachanoi
Placement: slopes, xerophytic beds, architectural hedges, and XXL pots. Leave 80–120 cm between plants for natural branching.
Planting in ground: raise on 15–30 cm mounds for drainage; spaced drip irrigation.
Compatibilities: Agaves, Dasylirion, Tephrocactus, xerophytic grasses.
Differentiation from Species Similar to Trichocereus pachanoi
T. macrogonus (var. macrogonus): more spines per areole (up to ~20), including robust central spines up to 5 cm; sometimes more slender form.
T. peruvianus: high variability; many clones more spiny and with more glaucous tones; sometimes more spaced areoles.
Typical pachanoi: 6–8 ribs, short/scant spination, areoles every ~2 cm, fast thickening tissues, and flowers with dark hairs on tube.
Best Practices for Nursery Production of Trichocereus pachanoi
Density: beds at 30–40 cm between 20–25 L pots for rapid thickening; increase spacing in second year.
Fertigation: 0.8–1.2 mS/cm in nutrient solution at growth peak; foliar chelated corrections in microdoses.
Hygiene: 3–4 week quarantine for new entries; disinfection of beds and tools; new substrate for each propagation.
Clonal selection: maintain low-spine lines for retail, and high-vigor lines for landscaping.
Frequently Asked Questions (FAQ) about Trichocereus pachanoi
How much light does it need? Full sun with acclimation; indoors only with strong lighting and ventilation.
Does it tolerate frost? Brief frosts if dry; better to avoid below −3 °C. Recommended USDA 9a+.
How often is it watered? In summer, when most substrate is dry; in winter, almost dry.
How is it propagated? Very easy by cutting; also by seed with sterile handling and warmth.
Why is it yellow? Possible chlorosis due to high pH/hard water. Adjust irrigation pH and apply chelated iron.
Summary Technical Sheet of Trichocereus pachanoi
Height: 3–6 m (exceptionally more).
Stem diameter: 6–15 cm; ribs 6–8.
Flowering: nocturnal, white, fragrant; 19–24 cm.
Substrate: very draining; pH 5.8–6.5.
Irrigation: deep and spaced in warmth; dry in cold.
Fertilization: low N, high K, with micros.
Zones: USDA 9a–11 (8b with expert management and dry conditions).
TRICHOLAND: Mother Plants and Scale Production of Trichocereus pachanoi
At TRICHOLAND we select Trichocereus pachanoi for vigor, low spination, and uniformity. We offer wholesale lots in various calibers, rooted cuttings, mother plants, and technical advice on substrates, fertigation, and landscaping project implementation. Consult availability, phytosanitary documentation, and logistics according to destination.
With proper management of light, water, and substrate, Trichocereus pachanoi is one of the most rewarding and fastest columns for xerophytic gardens, collections, or commercial production. If you need a mix recommendation, nutritional plan, or specific integrated control for your climate, the TRICHOLAND technical team is at your disposal.