Also known as Bluestar · 1k saves
Amsonia
Amsonia, the genus most gardeners know as bluestar. We track 19 varieties; the ones most used by real gardeners.
The 17 most-saved Amsonia varieties
Browse all 19 Amsonia varieties →
2 species of Amsonia
Each one is a parent of the varieties above.
Track your Amsonia in Sow
Save the Amsonia you grow and get care reminders timed to your zone.
How to grow Amsonia
Whats common across all Amsonia varieties in our catalog — drawn from the care records of the 19 most-grown of them.
The Amsonia year
- PruneMay and June95% of varieties
Cut back stems by 1/3 after flowering to maintain a dense, mounded shape
- Spring CleanupFebruary95% of varieties
Cut back old, dead stems to the ground before new growth starts
- DivideMarch and September47% of varieties
Divide large, established clumps every 3-5 years in spring or fall
Do
- Water regularly during dry spells 🌱
- Prune after flowering to promote bushiness
- Water deeply during dry spells 🌱
- Mulch to conserve moisture
- Prune after flowering to shape the plant
Avoid
- Avoid overwatering to prevent root rot ❌
- Don’t prune in late fall or winter
- Avoid overwatering in winter ❌
- Overwater to prevent root rot ❌
What goes wrong with Amsonia
| Problem | What you'll see | What to do |
|---|---|---|
| Aphids | Sticky residue and distorted leaves | Use insecticidal soap or neem oil |
| Spider mites | Webbing and stippled leaves | Apply miticide or spray with water |
| None | This plant is virtually pest-free. | No action is typically required. Its milky sap deters most insects and herbivores. |
| Root rot | Wilting and yellowing leaves, mushy roots | Improve drainage, reduce watering, use organic fungicide |
| Powdery mildew | White powder on leaves | Improve air circulation and apply fungicide |
| Powdery Mildew | White powdery coating on leaves | Improve air circulation and apply fungicide if necessary |
Making more Amsonia
Division
- Dig up mature clump in early spring.
- Split into smaller sections with a sharp knife.
- Replant divisions immediately in desired location.
- Water thoroughly and mulch around divisions.
Seed
- Tuck seeds into moist soil in early spring, takes 4-6 weeks to germinate.
Amsonia questions
How many types of Amsonia are there?
The Sow catalog tracks 19 distinct Amsonia varieties. The most popular — ranked by 1k real gardeners — are shown first above.
What zones does Amsonia grow in?
Across its varieties, Amsonia covers USDA Zones 4–9. Individual varieties differ — each plant page lists its exact range, and Sow filters the catalog to your zone automatically.
When does Amsonia bloom?
Most Amsonia varieties bloom in mid-spring, late spring, spring. Staggering early, mid, and late varieties extends the genus's season in one bed.
Which Amsonia 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.