Sunflower
Helianthus annuus
📖 About this plant
A spectacular, fast-growing annual producing enormous daisy-like flower heads that track the sun (heliotropism) when young. Sunflowers range from dwarf varieties under 60 cm to towering giants over 3.5 m, with flower heads from 10 cm to 60+ cm across. They are grown for their striking ornamental value, edible seeds, and oil production. Sunflowers attract pollinators, birds, and beneficial insects to the garden.
🧑🌾 Care requirements
Full sun (8+ hrs)
Every 2-3 days
Moderate (40-60%)
18-30°C
Well-draining loam; tolerates poor soil and drought once established; pH 6.0-7.5. Deep roots help access nutrients in subsoil
Light balanced fertilizer at planting; sunflowers are heavy feeders — nitrogen side-dress when plants reach 60 cm tall; excess nitrogen delays flowering
🌐 Common Names
📋 Plant facts
- 🌍 Origin
- North America (central United States and Mexico)
- 📏 Max height
- 60-360 cm depending on variety (giant varieties exceed 3.5 m)
- 📐 Spread
- 30-60 cm
- 🕰️ Bloom time
- Summer - Fall
- 🎨 Bloom color
- Yellow
- 🍃 Foliage color
- Green
- ⏳ Lifespan
- Annual
- 📈 Growth rate
- Fast
- ☠️ Toxicity
- Non-toxic to humans; mildly toxic to dogs and cats — seeds and sprouts contain compounds that can cause gastrointestinal upset and lethargy if consumed in large amounts. Seeds are widely sold as bird and pet food in moderation
- 🌱 Propagation
- Direct sow seeds 2.5-5 cm deep after last frost when soil reaches 13°C; germinates in 7-10 days; thin to 30-60 cm apart depending on variety; succession sow every 2 weeks for extended bloom
🛡️ Health & Safety
Non-toxic to humans; mildly toxic to dogs and cats — seeds and sprouts contain compounds that can cause gastrointestinal upset and lethargy if consumed in large amounts. Seeds are widely sold as bird and pet food in moderation
Common issues
- Downy mildew in humid conditions
- Sunflower moth larvae in seed heads
- Birds eating maturing seeds (netting helps)
- Damping off in cold wet soil
- Stunted growth from root-bound conditions
💡 Care tips
- Direct sow seeds after last frost date
- Support tall varieties with stakes or trellis
- HARVEST seeds when back of head turns brown
- Attracts pollinators and birds to the garden
