How to grow Lobelia in the UK
Lobelia erinus
Lobelia (Lobelia erinus) is a flower that grows well in UK gardens. Hanging basket essential. Tiny seed — sow on surface. 'Sapphire' has the deepest blue. This guide covers when and how to sow Lobelia, the soil and position it likes, watering and feeding, companion planting, and when to harvest.
When to sow & grow Lobelia
Sowing and harvest window through the year (UK):
Jan | Feb Sow | Mar | Apr | May Plant | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
Soil, position & care
- Soil
- Any reasonable, moisture-retentive but free-draining soil
- Soil pH
- 6.0–7.5
- Position
- Full sun for most; some tolerate light shade
- Sowing depth
- Surface to 1 cm (check light requirement)
- Spacing
- 15–30 cm apart
- Sowing
- Sow under cover late winter–spring, or direct after the last frost
- Growing
- Water regularly; pinch tips for bushier plants
- Harvest & upkeep
- Deadhead often to prolong flowering
- Watch for
- Slugs and snails on seedlings; aphids on soft growth
Companion planting for Lobelia
No specific companion notes for this plant.
Add Lobelia to your free 12-month plan and get watering & sowing reminders — no sign-up needed.
Lobelia FAQs
When should I sow Lobelia in the UK?
In the UK, sow Lobelia in February. Sowing across these months gives the plant the right soil temperature and day length to establish well.
How much sun does Lobelia need?
Lobelia prefers partial sun (3–6 hrs).
Is Lobelia easy to grow?
Easy — good for beginners. Hanging basket essential. Tiny seed — sow on surface. 'Sapphire' has the deepest blue.