How to Grow Water Spinach
Ipomoea aquatica
Tender Warm Season Continuous Harvest
Water spinach is a fast-growing tropical vegetable prized in South-East Asian cooking for its tender hollow stems and arrow-shaped leaves. It needs heat, moisture, and a long warm season — in the UK it is best grown under glass. Start indoors in late spring, plant out when temperatures are reliably above 20°C, and harvest shoot tips every 1–2 weeks for continuous production.
When to Start
Start seeds indoors 6 weeks before your last frost date. Transplant outdoors once night temperatures stay above 15°C and soil has warmed to at least 20°C.
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Growth Stages
Sow seeds
Day 0 Germination
~7 days Harvest
~50 days Seed to harvest ~50 days
Approximate days from start
Care Essentials
- Apply a nitrogen-rich liquid fertiliser every 2–3 weeks throughout the growing season to support the rapid leafy growth. Water spinach is a heavy feeder in warm, wet conditions.
- Water spinach is a tropical semi-aquatic vegetable that thrives in heat and moisture. In temperate climates, grow in a warm greenhouse or polytunnel from late spring, or outdoors only in the warmest summers. It can be grown in wet soil, shallow trays of water, or a pond margin.
Growing Conditions
- Min. soil temperature
- 20°C+
- Germination temperature
- 22–30°C
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- Direct sow
- —
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Spacing & Planting
| Plant spacing | 20 cm |
| Row spacing | 30 cm |
| Sow depth | 1 cm |
| Mature height | 60 cm |
| Mature spread | 40 cm |
Growing Conditions
| Min. soil temperature | 20°C |
| Germination temperature | 22–30°C |
| Base growth temperature | 15°C |
| Photoperiod sensitivity | short day |
Frequently Asked Questions
- How far apart should I plant Water Spinach?
- Plant Water Spinach 20cm apart with 30cm between rows.
- Is Water Spinach frost hardy?
- Water Spinach is classified as Tender.
