Also known as Sunflower · 409 saves
Helianthus
Helianthus, the genus most gardeners know as sunflower. We track 25 varieties; the ones most used by real gardeners.
The 24 most-saved Helianthus varieties
See all 25 Helianthus varieties →Search this genus →
4 species of Helianthus
Each one is a parent of the varieties above.
Track your Helianthus in Sow
Save the Helianthus you grow and get care reminders timed to your zone.
How to grow Helianthus
Whats common across all Helianthus varieties in our catalog — drawn from the care records of the 25 most-grown of them.
The Helianthus year
- StakeMay and June88% of varieties
Stake tall varieties when plants reach 2-3 feet to prevent flopping.
- PlantMarch–May76% of varieties
Sow seeds directly after last frost or transplant seedlings.
- HarvestJuly–September76% of varieties
Cut for bouquets or leave seed heads to dry for birds.
- FertilizeMay–July40% of varieties
Apply balanced fertilizer once or twice early in the season.
Do
- Water deeply once a week during dry spells 🌱
- Deadhead spent flowers to encourage more blooms
- Water deeply once a week 🌱
- Apply a balanced fertilizer monthly during the growing season
- Deadhead faded flowers to encourage more blooms
Avoid
- Avoid overwatering to prevent root rot ❌
- Avoid overwatering, which can cause root rot ❌
- Do not plant in shady areas, as sun is essential
- Refrain from fertilizing late in the season
What goes wrong with Helianthus
| Problem | What you'll see | What to do |
|---|---|---|
| Aphids | Sticky residue and distorted leaves | Spray with neem oil or insecticidal soap |
| Sunflower beetle | Chewed leaves and defoliation | Use organic insecticidal sprays or handpick beetles |
| Spider mites | Fine webbing and speckled leaves | Use horticultural oil or insecticidal soap |
| Sunflower beetles | Chewed leaves and defoliation | Handpick beetles or use organic insecticide |
| Powdery mildew | White powder on leaves | Apply fungicide and improve air circulation |
| Powdery Mildew | White powder on leaves | Improve air circulation and apply fungicide |
| Downy Mildew | Yellow patches on upper leaf surfaces, fuzzy gray mold underneath | Improve air circulation and apply fungicide |
Making more Helianthus
Seeds
- Tuck seeds into moist soil in early spring
- Maintain consistent moisture for 2 weeks
- Seeds germinate in 7-10 days
Seed
- Tuck seeds into moist soil in early spring
- Keep soil consistently moist for 2 weeks
- Transplant seedlings after 4–6 weeks when established
Helianthus questions
How many types of Helianthus are there?
The Sow catalog tracks 25 distinct Helianthus varieties. The most popular — ranked by 409 real gardeners — are shown first above.
What zones does Helianthus grow in?
Across its varieties, Helianthus covers USDA Zones 4–10. Individual varieties differ — each plant page lists its exact range, and Sow filters the catalog to your zone automatically.
When does Helianthus bloom?
Most Helianthus varieties bloom in late summer, late summer to fall, summer to fall. Staggering early, mid, and late varieties extends the genus's season in one bed.
Which Helianthus should I choose?
Start from the most-saved varieties above — popularity across thousands of gardens is a strong signal of reliability — then filter by your zone and sun. In the Sow app you can preview any of them in a photo of your actual yard before you buy.