Also known as American Aster · 2.9k saves
Symphyotrichum
Symphyotrichum, the genus most gardeners know as american aster. We track 24 varieties; the ones most used by real gardeners.
The 22 most-saved Symphyotrichum varieties
Browse all 24 Symphyotrichum varieties →
5 species of Symphyotrichum
Each one is a parent of the varieties above.
Track your Symphyotrichum in Sow
Save the Symphyotrichum you grow and get care reminders timed to your zone.
How to grow Symphyotrichum
Whats common across all Symphyotrichum varieties in our catalog — drawn from the care records of the 24 most-grown of them.
The Symphyotrichum year
- DivideMarch and April92% of varieties
Divide clumps every 3-4 years to maintain vigor
- Pinch TipsMay and June79% of varieties
Pinch back tips until early June for denser, more compact growth
- Spring CleanupFebruary46% of varieties
Cut back old, dead stems to the ground before new growth appears
- PlantMarch, April, September and October38% of varieties
Plant transplants in spring or fall.
Do
- Water deeply during dry spells 🌱
- Deadhead spent flowers to encourage more blooms
- Apply mulch to conserve moisture
- Water consistently during dry periods 🌱
- Deadhead spent flowers to encourage reblooming
Avoid
- Avoid overwatering to prevent root rot ❌
- Avoid overwatering, which can cause root rot ❌
- Avoid overhead watering, which can encourage fungal diseases.
- Overwater in winter ❌
What goes wrong with Symphyotrichum
| Problem | What you'll see | What to do |
|---|---|---|
| Aphids | Sticky residue and distorted leaves | Use insecticidal soap or neem oil |
| Powdery Mildew | White powdery coating on leaves | Improve air circulation and apply sulfur-based fungicide |
| Lace Bugs | Leaves appear stippled, yellow, or bleached; tiny dark spots of excrement on undersides. | Spray with insecticidal soap or neem oil, ensuring good coverage of leaf undersides. Encourage beneficial predatory insects. |
| Aster Leaf Miner | Swollen, distorted leaves | Use neem oil or insecticidal soap |
| Powdery Mildew | White powdery coating on leaves | Improve air circulation and apply fungicide |
| Powdery mildew | White powder on leaves and stems | Improve air circulation and apply sulfur-based fungicide |
| Root Rot | Wilting and yellowing leaves with soft roots | Ensure well-draining soil and reduce watering |
Making more Symphyotrichum
Division
- Dig up mature plants in early spring or fall
- Separate clumps into smaller sections with roots intact
- Replant divisions at same depth and water thoroughly
- Allow 6 weeks for establishment
Seed
- Tuck seeds into moist soil in early spring; expect germination in 2-3 weeks.
Symphyotrichum questions
How many types of Symphyotrichum are there?
The Sow catalog tracks 24 distinct Symphyotrichum varieties. The most popular — ranked by 2.9k real gardeners — are shown first above.
What zones does Symphyotrichum grow in?
Across its varieties, Symphyotrichum 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 Symphyotrichum bloom?
Most Symphyotrichum varieties bloom in late summer, early fall, late summer to fall. Staggering early, mid, and late varieties extends the genus's season in one bed.
Which Symphyotrichum 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.