🌸 Tolumnia 'BlackBall' Care Sheet (Closed Terrarium Setup)
A bold miniature orchid featuring deep burgundy to nearly black blooms—compact, eye-catching, and perfect for high-light terrariums with airflow.
🔍 Quick Info
Type: Miniature epiphytic orchid (Oncidiinae)
Size: 5–12 cm tall
Flowers: Dark red to near-black with velvety texture; showy on thin, upright spikes
Blooming Season: Spring to late summer (can flower more than once per year)
Growth Habit: Fan-shaped with thin, wiry roots and small pseudobulbs
🌡️ Temperature & Humidity
Day Temp: 22–30°C
Night Temp: 16–20°C
Humidity: 60–80%
✅ Enjoys high humidity but requires airflow
⚠️ Not suitable for stagnant, fully sealed terrariums—needs drying between waterings
💡 Light
Requirement: Bright, indirect to filtered light
Natural Source: East-facing or very bright north-facing window
Artificial: LED grow light (12–14 hours/day)
✅ Likes higher light than most terrarium orchids
❌ Avoid direct midday sun—leaves are thin
💧 Watering
Frequency: 2–3× per week during warm months
Method: Soak roots fully, then allow to dry
✅ Wet–dry cycle is critical
❌ Do not keep roots constantly moist—this causes root rot
Water Type: RO, rain, or distilled only
🌱 Potting & Mounting
Best Option: Mounted on cork or driftwood, with minimal or no moss
Alternative: Tiny mesh pot with coarse bark or LECA
✅ Maximize air flow around roots
❌ Avoid sphagnum moss or dense substrates
🌬️ Air Circulation
Essential in closed terrariums
Add a small fan or open lid 2–3 times per week
Helps roots dry out properly and prevents rot/fungal issues
🌿 Feeding
Fertilizer: Orchid-safe liquid, 1/4 strength
Schedule: Weekly during growth
Flush: With plain water monthly to prevent salt buildup
⚠️ Care Tips
Place high in the terrarium for better light and airflow
Watch for soft, mushy roots—sign of overwatering
Remove old, dry fans and spent spikes to promote new growth
Monitor root colour:
Silvery = dry
Green = freshly watered
✅ Ideal For
Bright terrariums with airflow and minimal moss
Orchid lovers wanting bold miniature species
Intermediate growers who can manage wet-dry cycles