Sunflower at a glance
| Botanical name | Helianthus annuus |
|---|---|
| Family | Asteraceae |
| Other names | common sunflower |
| Plant type | Flower; annual |
| Size | 1.5 to 10 feet tall, 1.5 to 3 feet wide |
| Light | Full sun (6 or more hours of direct sun) |
| Water | Water seedlings regularly. Established plants handle short dry spells but bloom best with steady moisture. |
| Soil | Well-drained soil; tolerates average garden soil. |
| USDA hardiness zones | Grown as a summer annual in every zone. |
| USDA PLANTS symbol | HEAN3 |
When to plant sunflower
Sow seeds directly in the garden after the last frost, once the soil has warmed.
Turn these into real dates for your area with the planting calendar.
How to grow sunflower
- Choose a sunny spot, out of strong wind for tall types.
- Sow seeds about 1 inch deep where they will grow; they do not like being moved.
- Thin seedlings to the spacing on the seed packet.
- Water regularly while plants are young.
- Stake very tall varieties.
- Cut flowers for vases when the first petals open, or leave heads to ripen seed for birds.
Water and soil
Water: Water seedlings regularly. Established plants handle short dry spells but bloom best with steady moisture.
Soil: Well-drained soil; tolerates average garden soil.
Light: Full sun (6 or more hours of direct sun).
Common problems
- Birds and squirrels eat the seed
- Cover ripening heads with a paper bag or mesh if you want to save the seed.
- Plants fall over
- Tall types need shelter from wind or a sturdy stake.
Is sunflower safe for cats and dogs?
Non-toxic
Non-toxic
The ASPCA lists Sunflower (helianthus angustifolius) as non-toxic to cats and non-toxic to dogs. ASPCA entry.
If a pet chews a plant and you are worried, call your vet or the ASPCA Animal Poison Control Center (888-426-4435; a fee may apply). For people, call Poison Help at 1-800-222-1222. In an emergency, call 911.
Can you eat sunflower?
The seeds are edible once ripe. Petals and young flower buds are also edible.
Sunflower questions
Are sunflowers safe for pets?
The ASPCA lists sunflowers as non-toxic to cats and dogs.
How long do sunflowers take to bloom?
Many varieties bloom in about two to three months from sowing. Check the seed packet for your variety.
Do sunflowers come back every year?
The common garden sunflower is an annual, so it grows, blooms and sets seed in one season. Dropped seed may sprout the next year.
Sources
- NC State Extension Gardener Plant Toolbox: Helianthus annuus (size, light, soil, zones, poison rating)
- USDA PLANTS Database profile: Helianthus annuus L. (accepted name)
- ASPCA: Sunflower (pet toxicity)
- ASPCA Animal Poison Control: plants toxic and non-toxic to cats
- ASPCA Animal Poison Control: plants toxic and non-toxic to dogs
Written in our own words from the sources above. See our editorial policy. Spotted a mistake? Tell us.
