The Story
Plant Bio
Aloe marlothii, the mountain aloe, is a large, single-stemmed succulent with a dense rosette of large, grayish-green leaves armed with reddish-brown spines. It produces a spectacular, branched inflorescence with racemes of orange to yellow-red flowers.
This species is distinguished by its robust, tree-like stature and its uniquely branched, often horizontal flower stalks. The persistent, dried old leaves form a 'petticoat' on the stem.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Cactus Succulent
Height
120 inches
Width
60 inches
Light
Full Sun, Partial Sun
Zones
9, 10
Water
Low
Humidity
Low
Lifespan
Decades
Native To
Southern Africa
Toxicity
Toxic to pets and humans if ingested
Bloom period
Winter – Early fall
In flower about 9 months of the year
Planting
How to Grow
- Tuck well-draining cactus soil around roots for optimal growth.
- Mist cuttings lightly to encourage root development, especially in warm months.
- Place plant in full sun for at least 6 hours daily for best flowering.
- Water sparingly during winter, allowing soil to dry completely between watering.
- Transplant in spring when plant outgrows its container, avoiding excessive disturbance.
- Apply a cactus-specific fertilizer monthly during the active growing season.
Pro Tip
Use a gritty, well-draining soil mix and avoid overwatering to prevent root rot.
Keep It Thriving
Care Guide
Do
- Provide full sun for robust growth ☀️
- Use cactus or succulent fertilizer monthly during summer
- Ensure excellent drainage to prevent waterlogging
- Protect from frost in colder zones
Don't
- Avoid overwatering, especially in winter ❌
- Do not place in low light areas
- Refrain from using heavy soil that retains moisture
- Never ignore pest signs
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Pest Check | ||||||||||||
| Plant | ||||||||||||
| Winter Prep |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Multiply
Propagation Methods
Good to Know
Common Questions
Mountain Aloe questions
What zones can Mountain Aloe grow in?
Mountain Aloe is hardy in USDA Zones 9–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Mountain Aloe deer resistant?
Yes — Mountain Aloe is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Mountain Aloe bloom?
Mountain Aloe typically blooms in winter through early fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Mountain Aloe need full sun?
Mountain Aloe does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is Mountain Aloe drought tolerant?
Yes — once established (usually after the first full season), Mountain Aloe handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
More Aloe to compare
Aloe Black Gem
Aloe Aloe black gem
Safari Rose Aloe
Aloe vera 'Safari Rose'
Cooper's Aloe
Aloe cooperi
Compton's Aloe
Aloe comptonii
Tilt-Head Aloe
Aloe speciosa 'Tilt-Head Aloe'
Coral Aloe
Aloe striata
Keep exploring
Explore the genus
Hardy in your zone?
Grow Mountain Aloe with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.