How to Grow Diascia
Diascia barberae
Diascia (Twinspur) is a half-hardy trailing annual for full sun to light shade and free-draining compost. Usually bought as young plants in spring. Plant out after last frost into hanging baskets, window boxes, and container edges. Prefers cooler conditions — thrives in typical UK summers but may pause flowering in extreme heat. Feed fortnightly. Shear back after the first flush for a strong autumn repeat. Not frost-hardy; some varieties are borderline perennial in mild areas.
When to Start
Sow indoors 7 weeks before last frost, or direct sow outdoors after frost risk has passed and soil reaches 10°C.
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Growth Stages
Approximate days from start
Care Essentials
- Balanced liquid feed every two weeks. Avoid overfeeding — diascia prefers lean conditions and flowers better without excess nitrogen.
- Dainty trailing plant with masses of small twin-spurred flowers in pink, coral, or white. Prefers cooler conditions than most bedding — thrives in UK summers. Flowers best in spring and autumn, may pause in extreme heat. Excellent for baskets and window boxes.
Growing Conditions
- Min. soil temperature
- 10°C+
- Sow indoors
- —
- Transplant out
- —
- First harvest
- —
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Spacing & Planting
| Plant spacing | 20 cm |
| Row spacing | 25 cm |
| Mature height | 25 cm |
| Mature spread | 30 cm |
For trailing varieties in hanging baskets and containers. Creates a delicate cascade of flowers at this spacing.
Pests & Diseases
Pest Slugs and Snails
Identification: Irregular holes in young leaves, slime trails, seedlings eaten overnight
- Beer traps
- Copper tape around containers
- Evening hand-picking
- Ferric phosphate pellets (wildlife-safe)
Disease Root Rot Pythium spp.
Symptoms: Wilting despite moist soil, brown mushy roots, plant collapse from the base
Treatment: Remove affected plants. Improve drainage. Allow compost to dry slightly between waterings.
Prevention: Use free-draining compost. Never let pots sit in water. Ensure drainage holes are clear.
Growing Conditions
| Min. soil temperature | 10°C |
| Base growth temperature | 8°C |
| Min. daylength to start | 11h |
| Photoperiod sensitivity | day neutral |
Frequently Asked Questions
- How far apart should I plant Diascia?
- Plant Diascia 20cm apart with 25cm between rows.
- When does Diascia flower?
- Diascia typically flowers approximately 45 days after transplanting.
- Is Diascia frost hardy?
- Diascia is classified as Half Hardy.
