Sunflower is an annual grown for its yellow blooms, which open in summer. It's hardy across USDA zones 2 through 11. Its summer flowers are a real draw for honeybees, native bees, and butterflies.
Zones
2-11
pH Range
5.5-8
Sun
Full Sun
Days to Maturity
80
Score Sunflower on your exact land.
Zone averages can't see the slope, soil, frost, and sun that decide whether sunflower actually takes — and those shift from one yard to the next. Enter your address and we'll score sunflower against your land's real conditions.
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What Sunflower is
Sunflower grows as an annual and reaches around eight feet at maturity. It blooms yellow in summer.
How to grow Sunflower
Sunflower grows in USDA zones 2 through 11. Sunflower does best in full sun — at least 6 hours of direct sun a day — and soil from pH 5.5 to 8, on well-drained ground. It needs around 1,500 growing degree days to mature and a growing season of at least 70 frost-free days, which is why climate matters as much as soil.
USDA Zones
2-11
USDA PHZM 2023
Soil pH
5.5 - 8
USDA PLANTS Database
Sun
Full Sun
plant_species_v5.csv
Drainage
well (dry spells)
plant_species_v5.csv
Frost Tolerance
41°F
plant_species_v5.csv
Days to Maturity
80 days
Common sunflower; annual; seed harvest after head matures.
USDA-NRCS; Johnny's
GDD Required
1500+
plant_species_v5.csv
Mature Height
8 ft
plant_species_v5.csv
Frost-Free Days
70+
plant_species_v5.csv
Start the season right
Plant sunflower in full sun with at least 6 hours of direct sun, once the soil has warmed and frost risk has passed.
Match the soil
Sunflower prefers pH 5.5 to 8 (USDA PLANTS Database). A quick soil test from your local Extension lab tells you whether to add lime or sulfur to land in band.
Water steadily
Keep the root zone evenly moist through establishment. A 2–3 inch mulch layer holds moisture without waterlogging.
Harvest at its peak
Cut sunflower blooms in the cool of the morning, just as they open, for the longest display.
Good to know
Good news for pet owners — sunflower isn't known to be toxic to dogs or cats. (Source: ASPCA.)
Sunflower is a standout pollinator plant — high value to bees and other pollinators. (Source: Xerces Society, Pollinator Partnership.)
Where Sunflower thrives
On hardiness alone, sunflower grows across most of the country — its range (USDA zones 2 through 11) is unusually wide. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.
Zones 2–11·Where Sunflower growsOpen map →
Continental US shown — Alaska and US Pacific territories sit outside the federal map's polygon dataset.
On USDA hardiness-zone overlap, Sunflower can grow in these states:
See if Sunflower will thrive on your land
Zone averages are a start. Your exact soil pH, drainage, sun exposure, and frost dates shape whether sunflower actually takes — we score it against the real conditions at your address.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Frequently Asked Questions
Can I grow Sunflower in my zone?
Sunflower grows in USDA hardiness zones 2 through 11 (USDA PHZM 2023). Zone is one factor — soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.
When should you plant Sunflower?
Most growers plant sunflower after the last spring frost, once the soil has warmed, leaving enough of the season for its 70-day frost-free need. Your local frost dates set the exact window — a Growable Ground report reads them for your address.
How much sun does Sunflower need?
Sunflower needs full sun — a spot that catches at least 6 hours of direct summer sun a day. In more shade it still grows, but usually gives a smaller, later crop. The catch is that a yard rarely gets even light everywhere — a fence, the house, or one tall tree can quietly take those hours. A Growable Ground report reads the real sun-hours across your land, canopy and buildings included, so you can pick the brightest bed before you plant.
What soil does Sunflower need?
Sunflower prefers soil pH 5.5 to 8, on well-drained ground (USDA PLANTS Database). Your report scores your parcel's actual soil against that using USDA SSURGO data.
Does Sunflower attract pollinators?
Yes — sunflower's flowers are a strong nectar and pollen source for honeybees, native bees, and butterflies (Xerces Society, Pollinator Partnership).
Is Sunflower safe for pets?
Sunflower is not known to be toxic to dogs or cats based on available data (ASPCA). Always supervise pets around new plantings.