Plant out your Sunflower this month — conditions are right now.
Growing Calendar
This month: May
Log to journalMove seedlings outside carefully
- •Harden off plants
- •Prepare soil outdoors
- •Space plants correctly
- •Water well after planting
Watch Out For
Slugs eat young seedlings
protect with copper tape or grit and start in pots indoors for best results before planting out
Tall varieties topple in wind
stake with a cane tied loosely at 50cm and again at 1m as they grow
Birds eat the seeds after flowering
net the heads or harvest once petals drop and dry them indoors
Grown Organically
Every method in this guide works with natural systems — no synthetic chemicals, no shortcuts.
Read our approachCommon Questions
About growing Sunflower in the UK
When do I sow sunflowers in the UK?
Sow sunflowers indoors from April in individual pots (they dislike root disturbance), or sow directly outside from mid-May after the last frost. They grow fast and will flower in 10–12 weeks.
Why is my sunflower not flowering?
Sunflowers need full sun — at least 6–8 hours a day. In shade or partial shade, plants produce lots of foliage but few or no flowers. Ensure the plant is in the sunniest spot available.
How tall do sunflowers grow in the UK?
Standard varieties reach 1.5–3m. Dwarf varieties stay at 30–60cm and are better for containers and exposed spots. Giant varieties (Mongolian Giant, Russian Giant) can exceed 4m in a warm, sheltered spot.
Can sunflowers be grown in containers?
Dwarf varieties grow well in large containers (at least 30cm). Full-size varieties need deep, fertile soil to reach their potential and are better suited to open ground or large raised beds.
Member guides
There's more to growing Sunflower than this guide covers.
Seasonal reminders, deeper guides, and the small adjustments that change a harvest.
