SproutSmart
SproutSmart™ Intelligent Garden Sowing

Sunflower

Family: Asteraceae Oilseed and ornamental annual

Planting Schedule

Provide your location or planting zone to unlock dates and add Sunflower to a garden.

Golden sunlight blooms with a confident, upright presence—Sunflower seeds yield heads that open like warm lanterns, their petals radiating rich, honeyed color.

The texture is bold and substantial, with a satisfying snap to the seed and a deeply aromatic, nutty character that shines in simple, roasted preparations and classic sunflower spreads. Grow Sunflower for show-stopping garden color and a dependable harvest at about 70 days, perfect for feeding the birds and delighting your own seed-saving rituals.

Light: Full SunMaturity: 70 DaysHabit: Upright

Botanical illustration of Sunflower

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Sunflower Planting Dates by USDA Zone

Estimated US hardiness-zone windows for sow, transplant, and harvest. Enter a US ZIP above for exact local dates, or open a zone below.

Zone Start Indoors Sow / Transplant Harvest
Zone 1a Protected Environment Only
Zone 1b Protected Environment Only
Zone 2a Direct Sow May 25th Aug 3rd – Aug 29th
Zone 2b Direct Sow May 15th Jul 24th – Aug 25th
Zone 3a Direct Sow May 15th Jul 24th – Sep 1st
Zone 3b Direct Sow May 19th Jul 28th – Sep 21st
Zone 4a Direct Sow May 15th Jul 24th – Sep 24th
Zone 4b Direct Sow May 13th Jul 22nd – Sep 27th
Zone 5a Direct Sow May 8th Jul 17th – Sep 30th
Zone 5b Direct Sow May 4th Jul 13th – Oct 5th
Zone 6a Direct Sow May 1st Jul 10th – Oct 10th
Zone 6b Direct Sow Apr 25th Jul 4th – Oct 16th
Zone 7a Direct Sow Apr 20th Jun 29th – Oct 20th
Zone 7b Direct Sow Apr 10th Jun 19th – Oct 28th
Zone 8a Direct Sow Apr 1st Jun 10th – Nov 5th
Zone 8b Direct Sow Mar 23rd Jun 1st – Nov 12th
Zone 9a Direct Sow Mar 6th May 15th – Nov 26th
Zone 9b Direct Sow Feb 9th Apr 20th – Dec 9th
Zone 10a — Oct 1st Dec 10th – Feb 28th
Zone 10b — Oct 1st Dec 10th – Feb 28th
Zone 11a — Oct 1st Dec 10th – Feb 28th
Zone 11b — Oct 1st Dec 10th – Feb 28th
Zone 12a — Oct 1st Dec 10th – Feb 28th
Zone 12b — Oct 1st Dec 10th – Feb 28th
Zone 13a — Oct 1st Dec 10th – Feb 28th
Zone 13b — Oct 1st Dec 10th – Feb 28th

Crop Details

TraitValue
Days to Maturity70
Sun RequirementsFull SunFull sun
Growth HabitUpright
Support NeededNone
Planting DepthNormal
Germination Temp (°F)70
Min Soil Temp (°F)55
Min Night Temp (°F)40
Harden Off (days)Not Required

Culinary Notes


Chef's Note

Sunflower seeds bring a bold, toasty nuttiness with real crunchy bite—perfect when you want flavor without going soft. Toast them hard, salt them hot, and they’ll hold their texture in salads, spreads, and gritty little sauces where other seeds might blur.

Best Uses

  • dry-roasting seeds until fragrant, then salting hard for snack and topping
  • grinding into sunflower seed butter for nut-free spreads and sauces
  • stirring toasted seeds into grain salads where they stay crunchy
  • folding seeds into pesto-style pastes (seed + oil + acid + garlic)

Flavor Profile

deeply nutty, roasted-toasty aroma crisp seed snap with a buttery, oily finish warm honeyed character

Kitchen Pairings

lemon garlic black pepper olive oil honey smoked paprika

Frequently Asked Questions


What are common pests or diseases on Helianthus annuus, and how do I control them?
Watch for sunflower moth/caterpillars and chewing leaf insects; hand-pick early outbreaks and use an insect net or row cover until flowering. If you see white, powdery growth on leaves, treat with a horticultural oil or potassium bicarbonate and avoid wetting foliage since powdery mildew spreads quickly in humid, still air.
How often should I water Helianthus annuus during active growth?
Water deeply so the top 6–8 inches of soil stay evenly moist, typically about 1–2 times per week depending on heat and rainfall. During bud formation and early flowering, don’t let the soil dry out completely—consistent moisture supports larger heads, but avoid waterlogged soil to prevent root stress.
How can I tell when Helianthus annuus is ready to harvest?
Harvest when the back of the flower head turns yellow to tan and the seeds look plump with tight, mature shells (often about 70 days). The outer petals should have withered, and you should be able to rub a seed from the head without it being soft or hollow.