Blue star (Amsonia ciliata var. filifolia)
Amsonia ciliata var. filifolia, or Blue star, is a low-maintenance perennial offering showy powder blue flowers and excellent fall color.
Complete Plant Information
Overview
The Amsonia ciliata var. filifolia, commonly known as Blue star, is a delicate yet resilient herbaceous perennial valued for its fine texture and subtle spring blooms. This variety is especially attractive due to its narrowly linear foliage, setting it apart from the species form. Gardeners prize this Blue star for its low maintenance needs and adaptability across the growing season, providing interest from spring until frost.
Native to the sandy soils of the Southeastern United States, Amsonia ciliata var. Filifolia forms neat, low clumps perfect for edging or mass planting. Its primary aesthetic draw is the terminal clusters of star-like, powder blue flowers appearing reliably in May. Furthermore, the foliage transitions to attractive yellow shades in the autumn, extending its ornamental appeal.
Functionally, this plant utilizes a milky latex when cut, which deters common herbivores, making it a reliable choice where deer pressure is a concern. For gardeners seeking reliable structure and vibrant, yet soft color, incorporating Amsonia ciliata var. filifolia into mixed borders or naturalized areas offers excellent year-round performance with minimal fuss.
Fast Facts
- Plant Family: Apocynaceae
- Plant Type: Herbaceous perennial
- Native Range: Southeastern United States
- Hardiness Zones: USDA Zones 5-9
- Size at Maturity:
- Height: 0.5-1 ft
- Spread: 0.5-0.75 ft
- Bloom Time: May
- Bloom Description: Powder blue
- Sun Exposure: Full sun to part shade
- Water Needs: Medium
- Maintenance Level: Low
How to Grow
Establish Amsonia ciliata var. filifolia during the cooler parts of the year, preferably spring or fall, allowing root systems to establish before summer heat arrives. This Blue star thrives in average, well-drained soils. While it prefers moderate moisture, excellent drainage is crucial, especially when siting the plant where it receives full sun.
For best performance, site Amsonia ciliata var. filifolia in full sun, though it tolerates light afternoon shade gracefully. Consistent watering is appreciated initially, but once mature, this plant demonstrates notable drought tolerance, particularly if established in deep, rich ground. Avoid heavy fertilization, as this cultivar prefers leaner soils reminiscent of its native habitat along sandy areas and rocky shores.
Maintenance for this perennial is exceptionally low. Pruning is generally unnecessary except to remove spent flower stalks if desired, although they usually fade gracefully. In early spring, simply cut back any old, lingering stems before new growth emerges. The milky sap released when stems are cut is harmless but can be mildly irritating, so wear gloves when actively working with the foliage.
Landscape Uses
The fine, thread-like foliage of Amsonia ciliata var. filifolia makes it an excellent textural element when used in mass plantings, providing a contrasting soft haze among bolder-leaved perennials. It is highly recommended for borders where its modest height (under one foot) prevents it from obscuring shorter foreground plants or blocking views. These plants integrate splendidly into cottage gardens, adding early summer color that complements dense plantings.
Due to its tolerance for drier conditions once established, Amsonia ciliata var. filifolia is ideal for rock gardens, especially those in full sun locations where other moisture-loving species might struggle. Furthermore, its suitability as a rain garden plant speaks to its ability to handle periodic fluctuations in moisture, provided the drainage remains adequate. The delicate powder blue flowers are excellent additions to fresh-cut arrangements.
Consider planting this Blue star near plants offering contrasting foliage colors, such as dark green ferns or plants with deep purple or burgundy leaves, to accentuate the lightness of the fine foliage and the pale blue blooms. Massing them provides the greatest visual impact when they transition to yellow in the fall.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Amsonia ciliata, commonly called fringed blue star or downy blue star, is a clump-forming perennial that is native from North Carolina to Florida west to Missouri, Arkansas and Texas. It is generally found in sandy soils. It typically grows to 2-3’ tall. Terminal clusters of star-like, light blue flowers bloom in mid spring (May) atop generally erect stems clad with narrowly elliptic to nearly linear, green leaves. The leaves tend to have fine hairs along their margins. Foliage turns attractive shades of yellow in fall. Stems and leaves produce a milky latex when cut or torn which protects the plant from herbivory. The blooms are attractive to butterflies and other insect pollinators. Var. Filifolia is native from southern Missouri to Florida and Texas into Mexico. It is most often found growing in sandy areas and along rocky shores. In southern Missouri, it is typically found in limestone glades, bald knobs and limestone bluff escarpments along streams in two counties in the area of the White River. This variety is distinguished from the species mainly by its narrower, linear foliage with margins that tend to be strongly revolute (rolled downward towards the underside).
Tolerances
- Deer
- Dry Soil
Potential Problems
This plant generally boasts excellent resistance to pests and diseases, providing a headache-free experience for the gardener. No known serious insect or disease problems typically plague the Amsonia ciliata var. filifolia. One significant advantage is its resistance to herbivory; deer tend to avoid this plant due to the milky latex produced in its stems and leaves when damaged. If deer are a persistent issue in your landscape, this Blue star offers a reliable, attractive alternative to more susceptible flowering perennials.
Frequently Asked Questions
What hardiness zones is Blue star suitable for?
Amsonia ciliata var. filifolia is suitable for USDA Hardiness Zones 5 through 9.
How large does Blue star grow?
This variety typically reaches a mature height between 0.5 and 1 foot tall, with a spread generally ranging from 0.5 to 0.75 feet wide.
When does Blue star bloom?
The perennial typically blooms in May, producing masses of powder blue, star-shaped flowers.
What sun exposure does Blue star need?
Amsonia ciliata var. filifolia performs best in full sun but tolerates areas receiving part shade, growing well as long as afternoon shade is light.
Conclusion
The Amsonia ciliata var. filifolia is a superb choice for gardeners seeking textural interest, reliable color, and exceptional hardiness under somewhat drier conditions. Its low maintenance profile, coupled with its deer resistance, cements its status as a valuable addition to any perennial border or rain garden. Plan to incorporate this beautiful Blue star in the spring or fall to ensure its fine foliage and delicate blooms flourish in your garden this season.
Wildlife Benefits
The blooms of Amsonia ciliata var. filifolia are noted for being attractive to butterflies and other crucial insect pollinators. Planting this species directly supports local pollinator populations during the mid-spring bloom period when many other nectar sources might be scarce. Its preference for native, sunny, and sometimes dry habitats means it specifically benefits insects adapted to these Southeastern environments.
Companion Planting Suggestions
Given its preference for well-drained soil and its 0.5 to 1-foot stature, Blue star pairs excellently with later-blooming perennials that enjoy similar sun exposures. Consider pairing it with plants that have contrasting textures or foliage, such as Hakonechloa grass for a weeping, shade-tolerant friend (if planted in the part-shade range), or companion it with drought-tolerant Salvias or Coreopsis. Since it tolerates dry spells, avoid pairing it with plants that demand consistently wet feet, which can lead to root rot in this Amsonia ciliata var. filifolia.
