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Plant Profiles / Saguaro
Photos: Wikimedia Commons
Saguaro
Carnegiea gigantea · Saguaro
The iconic tall, branching cactus of the Sonoran Desert. Very slow in cultivation, young saguaros make striking columnar pot plants.
Full sunLight
Every 3–4 weeksWater
ModerateCare level
Care at a glance
Light
Full sun
ShadeFull sun
Full, direct sun.
Water
Every 3–4 weeks
DryWet
Water sparingly in summer; keep dry in winter.
Humidity
Low
LowHigh
Dry air.
Temperature
0–45°C (32–113°F)
CoolWarm
Tolerates brief light frost when dry.
Growth
Very slow, columnar
SlowFast
A few centimetres a year.
Soil
Cactus mix
LeanRich
Very gritty mix.
Fertiliser
Once a year
RarelyOften
Diluted cactus fertiliser in spring.
Pet safety
Non-toxic
SafeToxic
Non-toxic; spines can injure.
About this plant
Saguaros are native to Arizona and north-west Mexico and can live over 150 years. They may take 50–70 years to grow their first arm. Nursery plants are seed-grown and stay potted for many years.
Best spots
Hot, sunny balconies and rooftops, and dry gravel gardens.
Plant facts
| Botanical name | Carnegiea gigantea |
| Family | Cactaceae |
| Origin | Sonoran Desert, USA & Mexico |
| Plant type | Columnar cactus |
| Mature size | Up to 12 m in the wild |
| Growth rate | Very slow |
| Spines | Grey-brown, stiff |
| Flowers | White, on mature plants only |
| Toxicity | Non-toxic |
| Propagation | Seed |
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
| Soft, dark spots | Rot from overwatering. |
| Yellowing | Sunburn or root problems. |
| Thin, pale tip | Not enough light. |
| Mealybugs | Treat with alcohol. |
| Slow growth | Normal. |
Common questions
How fast does it grow?
Very slowly.
When will it grow arms?
Often after 50 years or more.
Can it grow in a pot?
Yes, for many years.
Will it flower?
Only when very mature.
