Temperature
50–85°F
Keep away from winter window glass and heating vents.
Ladyfinger cactus
Mammillaria elongata
Ladyfinger cactus wants direct light and water every 14 to 30 days, once the soil is dry all the way through. Non-toxic to cats and dogs.
Light
Direct
LowMediumBright indirectDirect
A south or west window within a foot of the glass. In lower light the fingers stretch and thin.
Water
Every 14–30 days
Baseline for a 6-inch pot indoors. Check first: water when the soil is dry all the way through, not on a schedule.
Humidity
20% and up
Fine in normal household air. Prefers 30%.
Difficulty
Easy
Scores 1 of 5: Scores 1 of 5: clusters readily, flowers on a windowsill, and asks for almost nothing. Like most cacti it is killed by kindness in winter.
Habit
Clumping
Grows to 4–12 inches. No support needed.
Non-toxic to cats and dogs
Eating a large amount of any plant can still cause mild stomach upset.
Detail for cats → Detail for dogs →
What each authority says
- ASPCA
- No record page found under any name tested.
- NC State Extension
- Entry exists and records no poison data.
Light
Direct light. A south or west window within a foot of the glass. In lower light the fingers stretch and thin.
Water
Every 14 to 30 days in a 6-inch pot, when the soil is dry all the way through.
Treat the interval as a starting point and the test as the actual instruction. Pot size, light level and season all move the number.
| Method | soak and dry |
|---|---|
| Test before watering | the soil is dry all the way through |
Soil and potting
One part cactus mix, one part pumice.
Repot roughly every 4 years, or when roots come through the drainage holes and water runs straight through without absorbing.
Common problems
Ranked by how often each turns out to be the cause for this species. Each links to a diagnosis page with the causes ranked for this species.
- Root rot act today
- Leggy growth monitor
- Slow growth monitor
Pests
Recorded for this species. Each links to identification and treatment.
- Mealybugs this week
- Scale insects this week
Propagation
Offsets in soil. Roots in 21 to 56 days.
| Preferred method | offsets |
|---|---|
| Medium | soil |
| Time to root | 21–56 days |
| Node required | No |
| Best season | Spring and summer |
Sources
- North Carolina Extension Gardener Plant Toolbox — Mammillaria elongata (consulted; entry exists and records no poison data.) Checked 2026-09-12.
- Wikidata entity Q134530 — taxonomy and entity identity.
- Royal Botanic Gardens Kew, Plants of the World Online — Mammillaria elongata Accepted name; family Cactaceae. Checked 2026-09-12.
- Photograph: 3268zauber, Wikimedia Commons , CC BY-SA 3.0.
Compiled and edited by Tony Valcarcel · 2026-09-02
Tony Valcarcel is the editor and publisher of this database, not a horticulturist
or a veterinarian. Every fact above is drawn from the sources listed, and
toxicity severity is reported only where one of them stated it.
How this is sourced.
Last updated 2026-09-02