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Cut flowers5 varieties
Sunflower
Helianthus annuusFast-growing warm-season annual with upright stems and showy flower heads in many colors and forms.
Days to maturity
50–110 daysDays to germ.
7–14 daysSpacing
4–24 inHeight
36–180 inSun
SunVase life
5–7 daysHow we grow it
Germination
- Days to germ.
- 7–14 d
- Soil temp
- 70–75 °F
- Depth
- 0.5 in
- Pre-treatment
- None, but can soak seeds for up to 3 hours before sowing to speed germination.
- Viability
- 3 yrs
Culture
- Days to maturity
- 50–110 d
- Spacing
- 4–24 in
- Height
- 36–180 in
- Sun
- Sun
- Frost
- Hardy to ~32°F · to 32°F · tender
- Sow indoors
- No
- Outdoor / direct
- Yes
Harvest
- Cut stage
- When petals have color and just begin to lift away from center disc, but before the bloom is fully open.
- Vase life
- 5–7 d
- Handling
- Store out of direct sunlight; re-cut stems every 2 days
- Notes
- Yield: One stem per plant. SeeDS: When petals wither and drop, back of heads turn yellow-brown, and seeds get plump, cut with 1-2 ft of stem and hang by stem to dry. After 1-2 d, rub flower face to remove dried seeds.
Recent field notes
First blossoms
I’d estimate the tallest of these is just over 12” tall.
First seedlings spotted.
Timing · Zone 5a
JanFebMarAprMayJunJulAugSepOctNovDec
Outdoor / directMay 21 – Jun 18
Bloom (from outdoor)Jul 30 – Aug 27
Windows are anchored to an average last frost of May 21 (1 year in 10 as early as Apr 29, as late as Jun 2) and an average first frost of Sep 18 (1 year in 10 as early as Sep 6, as late as Oct 8). In a late or early year, slide them with it.
Compare in the calendarTrials
Every Sunflower sowingSeed sources, counts, ratings, and the observations kept against each one.Sunflower trials- Suits
- SuccessionEvery 2-3 wks over an 8-week window after LF
- Not for
- PinchPinching will arrest vertical growth.
- Cut-and-Come-AgainSide shoots after first cut
Varieties
5 varieties on recordNo photograph yetSunflower ‘American Giant Hybrid’
‘American Giant Hybrid’
Bright Yellow, DARK BROWN Center
‘Gummy Bear’
tryingNo photograph yetSunflower ‘Henry Wilde’
‘Henry Wilde’
tryingNo photograph yetSunflower ‘Midnight Rouge’
‘Midnight Rouge’
tryingNo photograph yetSunflower ‘Procut White Lite F1’
‘Procut White Lite F1’
trying