Germination temperature
About 21 °C (70 °F) indoors; outdoors sow once frost is over and the soil is at least 7 °C (45 °F).
Visit deodar-seeds.in Flower growing guide
Ornamental sunflowers come in dwarf, branching and tall cut-flower forms, in colours from cream to deep red. Sow the large seed directly in warm soil and full sun, and sow again every few weeks for a long season of flowers.
About 21 °C (70 °F) indoors; outdoors sow once frost is over and the soil is at least 7 °C (45 °F).
1.3-2.5 cm (1/2-1 in).
5-10 days.
Seed is covered; plants need full sun.
None needed.
Direct sow, or start in biodegradable pots 3-4 weeks ahead.
Sunflower seed is large and easy to handle. Choose the type first: single-stem pollenless varieties for cutting, branching varieties for a long display, dwarf varieties for pots and borders.
Not needed. The seed coat lets water in readily.
Not needed. Sunflower is a summer annual and germinates without cold treatment.
Not needed in a moist seedbed. For dry-season field sowings in India, TNAU soaks seed in a 2% zinc sulphate solution for 12 hours and shade-dries it before sowing.
Indoors, about 21 °C (70 °F). Outdoors, sow after all danger of frost has passed, once the soil has warmed to at least 7 °C (45 °F); warmer soil gives faster, more even emergence. Sunflowers do not survive frost.
1.3-2.5 cm (1/2-1 in). Cover the seed fully and firm the soil.
Well-drained soil in full sun with pH about 6.0-6.8. Avoid waterlogged ground, where seedlings are prone to root and stem rots.
Water the row after sowing and keep it moist, not soggy, until seedlings are up.
Sunflower seed germinates in darkness, so cover it fully with soil.
About 5-7 days at 21 °C (70 °F); up to 10 days outdoors.
Sunflowers resent root disturbance. If you start them indoors, sow in biodegradable pots 3-4 weeks before planting out, move them once they have true leaves, and tear off any pot rim above the soil so it does not wick water away.
Space 60-150 cm (2-5 ft) varieties about 15 cm (6 in) apart, taller ones at least 30 cm (1 ft), giants about 60 cm (2 ft) and branching types 45-60 cm (18-24 in). For cut flowers, closer spacing gives smaller heads: 5-10 cm (2-4 in) apart gives 5-8 cm (2-3 in) blooms, 10-15 cm (4-6 in) apart gives 10-13 cm (4-5 in) blooms.
Keep weeds down by hoeing or mulching, and side-dress with a slow-release general fertilizer once plants have several true leaves.
Cause: birds and other animals take the seed and young shoots. Fix: cover rows with netting until seedlings are established; reflective ribbons or scarers help keep birds away from ripening heads.
Cause: Pythium or Rhizoctonia root and stem rot in cold, wet soil. Fix: sow into warm, well-drained soil and do not overwater.
Cause: root disturbance. Fix: sow direct or use biodegradable pots planted whole.
Cause: aphids, whose honeydew grows sooty mould. Fix: rinse them off and encourage predators; sunflowers attract many beneficial insects, so avoid broad insecticide sprays.
Cause: fungal leaf spots or powdery mildew, usually starting on the oldest leaves. Fix: give plants space and air; healthy plants usually keep flowering.
Single-stem types flower once, 50-95 days after sowing depending on cultivar. Sow them every 1-3 weeks, or branching types every 2-3 weeks, for continuous flowers.
Sunflower is grown in several seasons in India; TNAU lists June-July, October-November, December-January and April-May sowings with irrigation. Avoid frost and waterlogged soil.
Established plants tolerate some drought, but water regularly for about 20 days before and after flowering for strong stems and good heads.
Cut when the petals are just lifting from the centre, before the flower opens fully. Strip all leaves except the two nearest the bloom and stand stems in cool, clean water; they last about 7-10 days.
Pollenless cut-flower varieties do not drop yellow pollen on tables or clothes. Branching types shed pollen, which shortens their vase life.
Sow sunflowers directly in warm soil and full sun, and sow again every few weeks for months of flowers.
They do not transplant well. If you start them early, use biodegradable pots, sow 3-4 weeks before planting out and plant the whole pot without disturbing the roots.
Single-stem ornamental and cut-flower types bloom 50-95 days after sowing, depending on the variety; many are ready to cut from about 50-60 days.
Dwarf and most semi-dwarf types stand on their own. Giant varieties over about 2.4 m (8 ft) often need a stake, especially in windy spots.
They were probably cut too open. Cut when petals are just lifting from the centre, remove most leaves and keep the water clean and cool.