Species
Amsonia tabernaemontanaBluestar4 other cultivars
The Story
Plant Bio
Amsonia tabernaemontana 'String Theory' is a deciduous perennial with graceful, narrow blue-green leaves forming a bushy habit and producing clusters of star-shaped, pale blue flowers in late spring to early summer.
This cultivar is distinguished by its compact, mounding habit and very fine, thread-like foliage. It provides excellent textural contrast and turns a brilliant golden-yellow in the fall.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Perennial
Height
20 inches
Width
34 inches
Light
Full Sun, Partial Sun
Zones
4, 5, 6, 7, 8, 9
Water
Moderate
Humidity
Average
Lifespan
Perennial
Native To
North America
Toxicity
Sap may cause mild skin irritation
Bloom period
Late spring – Late fall
In flower about 7 months of the year
Marketplace
Where to Buy
Shipping costs Year-round shipping Free shipping
Planting
How to Grow
- Tuck seeds or cuttings into moist soil in early spring.
- Water regularly until established, about 6 weeks.
- Place in full sun for optimal flowering.
- Apply a balanced fertilizer in early spring.
- Prune lightly after flowering to maintain shape.
- Mulch around base to retain moisture.
Pro Tip
Ensure well-drained soil and full sun for best blooms.
Keep It Thriving
Care Guide
Do
- Water regularly during dry spells 🌱
- Prune after flowering to promote bushiness
- Apply fertilizer in spring for vibrant growth
Don't
- Avoid overwatering in winter ❌
- Don’t prune in late fall or winter ❌
- Avoid heavy clay soil without amendments ❌
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Prune | ||||||||||||
| Spring Cleanup |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
String Theory Bluestar questions
What zones can String Theory Bluestar grow in?
String Theory Bluestar is hardy in USDA Zones 4–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is String Theory Bluestar deer resistant?
Yes — String Theory Bluestar is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does String Theory Bluestar bloom?
String Theory Bluestar typically blooms in late spring through late fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does String Theory Bluestar need full sun?
String Theory Bluestar does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is String Theory Bluestar drought tolerant?
Yes — once established (usually after the first full season), String Theory Bluestar handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
More Amsonia to compare
Blue Star Amsonia
Amsonia tabernaemontana 'Blue Star'
Storm Cloud Blue Star
Amsonia tabernaemontana 'Storm Cloud'
Arkansas Blue Star
Amsonia hubrichtii
Bluestar
Amsonia tabernaemontana
Blue Ice Amsonia
Amsonia orientalis 'Blue Ice'
Blue Ice Bluestar
Amsonia tabernaemontana 'Glacier Blue'
Keep exploring
Explore the genus
Collections featuring this plant
Grow String Theory Bluestar with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.