Flower · Ornamental / Cut Flower
Sunflower
Helianthus annuus
A fast-growing annual grown for its large, sun-following flower heads. Ranges from compact dwarf varieties suited to containers to towering giants that need sturdy support.
At a glance
Water
Medium
24–40 fl oz/wk
Light
Full sun
6–8 hrs/day
Space
Medium
18 in
To maturity
85–95 days
Edible parts: Seeds
Family: Aster
A huge family including lettuce, sunflowers, and marigolds. Recognizable by composite flower heads made of many tiny florets packed together.
Harvest
For cut flowers, pick once petals have just opened; for seed, wait until the back of the head turns brown and petals dry and fall.
Growing conditions
- Temperature
- 50–90 °F
- Soil pH
- 6–7.5
- Soil type
- Well-drained, moderately fertile soil
- Climate
- Frost-tender annual.
- Growing season
- Direct-sow after the last frost once soil has warmed.
- Nitrogen
- Medium (≈30–60 ppm)
- Humidity
- Medium (≈40–70 %)
- Planting unit
- Seed
- Support
- Tall varieties benefit from a stake, especially in windy spots.
- Feeding schedule
- A balanced feed at planting is usually enough; too much nitrogen can produce tall, weak stalks.
- Pest resistance
- Moderate - watch for aphids and birds once seed heads form
- Pruning
- None for single-stem types; pinch young branching types to encourage bushier growth.
Where it grows
- In-Ground GardenIdeal
- Raised BedIdeal
- Container / PotPossible— Dwarf varieties only; tall types are too heavy and deep-rooted for a pot.
- HydroponicNot recommended— Size and root depth don't suit standard hydroponic systems.
- Vertical / TrellisNot recommended— Self-supporting rather than climbing; tall types need a stake instead.
- WindowsillNot recommended— Needs more light and space than a windowsill offers.
Companions & antagonists
No known companion pairings yet.
Sources
- Growing Sunflowers for Beginners — West Virginia University Extension
- Sunflowers — University of Minnesota Extension