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Plant Profiles / Mexican fence post cactus
Photos: Wikimedia Commons
Mexican fence post cactus
Pachycereus marginatus · Organ pipe cactus
A tall, upright cactus with ribbed green columns edged in neat rows of short spines. Grown as a living fence in Mexico.
Full sunLight
Every 2–3 weeksWater
Very easyCare level
Care at a glance
Light
Full sun
ShadeFull sun
Full sun.
Water
Every 2–3 weeks
DryWet
Water when dry.
Humidity
Low
LowHigh
Dry air.
Temperature
2–40°C (36–104°F)
CoolWarm
Frost tender.
Growth
Moderate, columnar
SlowFast
Grows 3–5 m in the ground.
Soil
Cactus mix
LeanRich
Free-draining.
Fertiliser
Twice a year
RarelyOften
Diluted cactus fertiliser.
Pet safety
Non-toxic
SafeToxic
Non-toxic.
About this plant
Native to central Mexico, the fence post cactus grows into dense columns used as hedges. In pots it makes a clean, architectural statement.
Best spots
Sunny balconies, rooftops, modern courtyards and large pots.
Plant facts
| Botanical name | Pachycereus marginatus |
| Family | Cactaceae |
| Origin | Central Mexico |
| Plant type | Columnar cactus |
| Mature size | 3–5 m |
| Growth rate | Moderate |
| Spines | Short, in neat rows |
| Flowers | Small red-pink |
| Toxicity | Non-toxic |
| Propagation | Stem cuttings |
Seasonal care calendar
J
F
M
A
M
J
J
A
S
O
N
D
Active growth
Fertilise
Keep dry
Active growthFertiliseKeep dry
Based on Southern Hemisphere seasons.
Troubleshooting
| Yellow patches | Sunburn. |
| Soft spots | Overwatering. |
| Thin growth | Low light. |
| Frost damage | Protect in winter. |
| Toppling | Use a heavy pot. |
Common questions
Can it be a hedge?
Yes, planted in a row.
Is it pet safe?
Yes.
Does it branch?
Mainly from the base.
Can it grow in a pot?
Yes.
