Mexican Fence Post Cactus Pachycereus Marginatus

Growth Habit: Upright, columnar stems that grow in tall, vertical clusters
Bloom Season: Spring to summer
Dormancy: Winter
Sun Exposure: Full sun preferred
Soil Needs: Well-draining cactus mix with slightly acidic to neutral pH
Hardiness Zones: Zones 9–11; protect from hard frost
Native To: Central Mexico

After Arrival
Carefully unpack your cactus as soon as it arrives. If it’s a cutting, don’t be alarmed if the base looks dry, that’s completely normal. Cuttings are fresh segments taken from mature plants that don’t yet have roots. They need time to callous over, so let them rest in a dry, shaded spot for a few weeks before planting in cactus soil. Avoid watering during this period, as moisture too soon can lead to rot. If you received a rooted plant, it already has a developed root system and can be potted right away. Once planted, wait about a week before giving it a light watering to help it settle into its new environment.

Sunlight Introduction
Let your cactus adjust in bright, indirect light for a few days before moving it into full sun, especially if it was boxed during shipping.

Light
Outdoors, this cactus thrives in full sun. Indoors, place it in your brightest window, ideally with 6+ hours of direct light each day.

Watering
Stick with the soak-and-dry method. Water deeply, then let the soil dry out completely before watering again. In winter, reduce watering to once a month or less.

Soil & Pots
Use a gritty, well-draining cactus mix with sand or perlite. Terracotta pots work well. Always use a pot with drainage holes to prevent rot.

Growth & Repotting
This cactus grows steadily and can gain several feet over time. Repot every 2–3 years or when it outgrows its container. After repotting, wait about a week before watering to allow the roots to settle.

FAQ

How fast does it grow?
The Mexican Fence Post grows faster than many other columnars, expect several inches per year in ideal conditions.

How often should I water?
Only when the soil is completely dry. In warm months, every 1–2 weeks; in winter, much less.

Can it grow indoors?
Yes! Just make sure it gets enough direct light. A bright, sunny window is key.

Will it flower?
It can! Mature outdoor plants may produce small pink or red flowers in spring or summer, though flowering indoors is rare.

Do I need to fertilize?
Not necessary, but you can use cactus fertilizer at half strength during the growing season.