Cyrtosperma Johnstonii- Rare

Size: Single Plant | Pot included | Secure Packing

Cyrtosperma johnstonii (Giant Swamp Taro)
Grow in bright indirect light to partial sun; it thrives best in constantly wet or waterlogged soil and can even be grown in shallow water. Keep temperatures above 18 °C with high humidity, as it is a true tropical swamp plant. Use rich, organic, well-draining mud/soil, feed monthly with a balanced fertilizer, and ensure ample space—this plant becomes very large over time.

Cyrtosperma johnstonii Care Guide

Cyrtosperma johnstonii is a rare, dramatic aroid native to swampy regions of the South Pacific. It is admired for its massive arrow-shaped leaves, thick spiny petioles, and strong architectural presence. This plant is best suited for outdoor tropical gardens, water gardens, or very large conservatories.

---

🌱 Light Requirements

• Prefers bright, filtered sunlight

• Can tolerate partial sun to light shade

• Avoid harsh midday sun, which can scorch leaves

• Ideal placement: morning sun + afternoon shade

In very humid tropical areas, it can handle more sun than most aroids.

---

💧 Watering Needs

This is a semi-aquatic / swamp plant.

• Soil must be constantly moist to wet

• Can be grown:

  • In waterlogged soil

  • At pond edges

  • In shallow standing water (2–10 cm)

• Never allow the soil to dry out

⚠️ Dry conditions will cause rapid leaf decline.

---

🌍 Soil & Growing Medium

Best soil mix:

• Rich loamy garden soil

• Organic compost or well-rotted manure

• Clay or heavy soil that retains moisture

For pots (temporary or juvenile plants):

• Garden soil + compost + coco peat (2:1:1)

• Use large, deep containers with no fast drainage

---

🌡️ Temperature & Climate

• Ideal temperature: 22–35°C

• Minimum tolerance: Above 15°C

• Not frost-tolerant

• Thrives in hot, humid tropical climates

Perfect for coastal and southern Indian regions.

---

💨 Humidity

• Loves high humidity (70–90%)

• Naturally thrives near ponds, wetlands, and marshes

• No extra misting needed outdoors in humid zones

---

🌿 Fertilization

Heavy feeder due to its massive growth:

• Use organic compost or cow manure every 4–6 weeks

• Supplement with:

  • Balanced liquid fertilizer (once a month)

• Avoid chemical overuse in water gardens

---

🍃 Growth Habit & Size

• Extremely large plant

• Leaves can grow 1.5–2 meters long

• Strong underground corm system

• Slow to moderate growth initially, then vigorous once established

⚠️ Not suitable for small gardens or indoor spaces.

---

✂️ Pruning & Maintenance

• Remove yellowing or damaged leaves at the base

• Wear gloves – petioles may have sharp spines

• Keep surrounding area clear to allow leaf spread

---

🌱 Propagation

Propagation is done by:

• Corm division

• Side offsets during warm months

Steps:

1. Separate offsets with roots attached

2. Plant immediately in wet soil

3. Keep constantly moist until established

---

🐛 Pests & Diseases

Generally hardy, but watch for:

• Aphids

• Spider mites (in dry conditions)

• Root rot (only if water is stagnant and foul)

Preventive care:

• Maintain clean water

• Ensure natural airflow

---

⚠️ Toxicity

• Contains calcium oxalate crystals

• Toxic if ingested

• Keep away from pets and children

---

🌴 Landscape Use

• Water gardens & ponds

• Tropical landscaping

• Botanical collections

• Statement plant for large estates

---

✅ Quick Care Summary

• Light: Bright filtered light

• Water: Constantly wet / swampy

• Soil: Heavy, organic-rich

• Climate: Tropical, humid

• Difficulty: Moderate to advanced