Ipomoea lobata (Spanish Flag)
Botanical name: Ipomoea lobata
Common name: Spanish Flag, Firecracker Vine
Plant type: Tender annual climber
Height: 2–3 m (6–10 ft)
Spread: 1–2 m
Flowering: July to October
Spanish Flag is a fast-growing, twining climber prized for its unusual, bi-coloured flowers that open red and fade through orange, yellow and cream.
Position
- Sun: Full sun is essential for good flowering
- Shelter: A warm, sheltered spot gives the best results
- Support: Needs trellis, wires, obelisk or a fence to climb
Soil
- Type: Well-drained, moderately fertile soil
- pH: Neutral to slightly acidic
- Avoid overly rich soil, which encourages leafy growth at the expense of flowers
Sowing & Propagation
When to Sow
- Indoors: March to April
- Outdoors: Late May to early June (only after risk of frost has passed)
How to Sow
- Soak seeds in warm water for 12–24 hours before sowing
- Sow 1–2 cm deep in pots or modules
- Place in a warm position (18–21°C)
- Germination usually takes 7–14 days
Hardening Off
- Gradually acclimatise plants for 7–10 days before planting outside
Planting Out
- Plant out after the last frost
- Space plants 30–45 cm apart
- Water in well and provide support immediately
Watering
- Water regularly, especially in dry spells
- Do not allow soil to dry out completely
- Container-grown plants will need more frequent watering
Feeding
- Feed every 10–14 days with a balanced or high-potash liquid feed once flowering begins
- Too much nitrogen = lots of leaves, fewer flowers
Training & Care
- Gently tie in young shoots until the plant starts twining naturally
- Pinch out growing tips early to encourage bushier growth
- Remove faded flowers only if they become untidy (not essential)
Pests & Problems
- Generally trouble-free
- May occasionally attract:
- Aphids (treat early with water spray or soft soap)
- Slugs/snails on young plants
Growing in Containers
- Use a large pot (at least 30 cm diameter)
- Ensure excellent drainage
- Feed and water more frequently than plants in the ground
End of Season
- Killed by the first frost
- Can be allowed to self-seed in warm years, but not reliably in the UK
- Collect seed before frost if you want to grow it again next year
Why Grow Spanish Flag?
- Unusual, eye-catching flowers
- Excellent for tropical-style planting schemes
- Attractive to bees and pollinators
- Perfect for adding height and colour quickly