To wake up Colocasias from dormancy in the UK, you need to provide warmth, moisture, and light at the right time.
Best Time to Start in the UK
- Indoors: March to April (earlier if using a heat mat).
- Outdoors: Late May to early June, once nights stay above 10°C (50°F).
How to Wake Them Up
- Check for Viability
- If stored dry, inspect tubers for firmness and remove any soft or rotting parts.
- Provide Warmth
- Soil temperature must be at least 15°C (60°F) to break dormancy.
- A heat mat or propagator set to 18–21°C (65–70°F) speeds up sprouting.
- Rehydrate
- Soak tubers in warm water (25°C/77°F) for a few hours before planting to rehydrate them.
- Planting
- Use a deep pot with moist but well-draining compost.
- Plant the tuber 1–2 inches deep, with the growing tip facing up.
- Keep the compost lightly moist but not soggy.
- Provide Bright, Indirect Light
- Place in a warm, bright spot indoors (avoid strong direct sunlight at first).
- Once shoots appear, increase light levels gradually.
- Acclimate Before Moving Outdoors
- Around mid to late May, start hardening off by gradually exposing them to outdoor conditions over 1–2 weeks.
Colocasias should start growing within 2–6 weeks, depending on warmth and moisture levels.