Stokes' aster (Stokesia laevis 'Alba')

Overview

The striking Stokesia laevis ‘Alba’ offers gardeners reliable, vibrant color throughout the summer heat. This specific cultivar of Stokes’ aster showcases beautiful, pure white, fluffy flowers reminiscent of cornflowers, making it an excellent focal point in perennial beds. As an evergreen herbaceous perennial thriving in tough summer conditions, Stokesia laevis ‘Alba’ proves to be exceptionally valuable for both color persistence and low maintenance requirements.

Native to the coastal plains of the southeastern US, this selection adapts well to average garden conditions provided drainage is adequate. While it prefers consistent moisture, the plant exhibits surprising drought tolerance once established, which simplifies long-term care in sunny locations. Planting the white-flowered Stokes’ aster ensures light reflection in the evening garden and provides superb material for fresh bouquets.

Its manageable size, typically reaching only 1 to 1.5 feet tall and wide, makes Stokesia laevis ‘Alba’ perfectly scaled for edging pathways or integrating into mixed borders where taller plants might overwhelm neighboring perennials. Low maintenance combined with high aesthetic impact ensures this variety remains a favorite among experienced and new gardeners alike.

Fast Facts

• Plant Family: Asteraceae
• Plant Type: Herbaceous perennial
• Hardiness Zones: USDA Zones 5-9
• Size at Maturity:
  • Height: 1-1.5 ft
  • Spread: 1-1.5 ft
• Bloom Time: June to September
• Bloom Description: White
• Sun Exposure: Full sun
• Water Needs: Medium
• Maintenance Level: Low

How to Grow

Plant Stokesia laevis ‘Alba’ in the spring or fall for best establishment, ensuring it receives full sun exposure for the most prolific flowering. The most critical cultural requirement for this plant is excellent soil drainage; it thrives in average, medium-moisture soils, even preferring sandy types, but wet winter soil is frequently fatal. While it tolerates some filtered sunlight, maximum performance requires blasting sun.

Maintain medium moisture levels, especially during active growth and blooming periods in the summer months. Fertilizing is rarely necessary if the native soil drainage is suitable; rich, heavy compost can sometimes encourage flopping, which is a common issue for Stokes’ aster stems. Consistent moisture, but never soggy conditions, is the key to success.

To keep Stokesia laevis ‘Alba’ looking tidy and encourage repeat flowering, deadhead individual spent blooms regularly. Once the main flush of bloom passes, you can cut the spent flowering stems back entirely, or even trim the entire plant down to the basal foliage. Gardeners in the northern limits (Zone 5) should apply winter mulch to protect the crowns.

Landscape Uses

Stokes’ aster, particularly the white cultivar Stokesia laevis ‘Alba’ is superb for adding structure and long-lasting white accents along border fronts where its structure can be appreciated up close. Its medium height and neat, evergreen basal rosette make it an ideal transitional plant between lawn edges and taller background shrubs. Consider mass plantings for maximum visual impact utilizing its cloud of white summer blooms.

This variety integrates beautifully into traditional cottage gardens, blending well with classic companions like Salvia, Coreopsis, or Catmint, as they share similar sun and drainage preferences. Furthermore, due to its cultural tolerance for moisture, Stokesia laevis ‘Alba’ is an excellent choice for softening the edges of constructed water features, such as ponds or rain gardens, where drainage is slightly heavier but still adequate.

Standout Features

Flower Qualities

• Showy

Noteworthy Characteristics

Stokesia laevis, commonly known as Stokes’ aster, is native to wetlands, bottomlands, wet pinewoods, savannas and ditches mostly along the coastal plain from North Carolina to Florida to Louisiana. It is an evergreen perennial that typically grows to 1-2’ tall. It features fluffy, cornflower-like, violet blue flowers (to 2 1/2” across), each with notched rays surrounding a pincushion center of feathery disk florets. The cultivar ‘Alba’ specifically offers a stunning white coloration to this unique bloom form.

Tolerances

• Rabbit
• Drought

Potential Problems

Stokesia laevis ‘Alba’ generally boasts excellent pest and disease resistance, rarely suffering serious issues beyond the occasional caterpillar activity. The primary cultivation challenge specific to Stokes’ aster involves stem architecture; flower stems tend to flop, especially when weighed down by heavy rain or wind common in Midwestern summer thunderstorms. To prevent this, ensure stems are well-spaced or stake loosely if necessary. The most lethal threat is improper winter drainage; avoid planting in areas where water pools or remains soggy, as this leads directly to crown rot.

Frequently Asked Questions

What hardiness zones is Stokes’ aster suitable for?

Stokes’ aster (Stokesia laevis ‘Alba’) is reliably hardy in USDA Zones 5 through 9.

How large does Stokes’ aster grow?

This herbaceous perennial typically reaches a height between 1 and 1.5 feet, with a similar spread of 1 to 1.5 feet at maturity.

When does Stokesia laevis ‘Alba’ bloom?

Stokesia laevis ‘Alba’ produces its distinctive white flowers throughout the main summer period, generally blooming from June right through September.

What sun exposure does Stokes’ aster need?

For the best display of white blooms, Stokesia laevis ‘Alba’ requires full sun exposure, though it can tolerate some filtered light.

Conclusion

The pure white elegance of Stokesia laevis ‘Alba’ provides reliable summer color coupled with impressive resilience to heat and drought once established. Its low maintenance needs and unique, showy flowers make this Stokes’ aster cultivar an indispensable choice for sunny borders. Before planting, confirm your location falls within USDA Zones 5-9 and, most importantly, verify that your chosen spot enjoys fast, well-draining soil to celebrate this beauty for years to come.

Companion Planting

When designing a border around your Stokesia laevis ‘Alba’, select companions that share its love for sun, medium water, and excellent drainage. Grouping it near plants that bloom later in the season can extend the visual interest of the area, while selecting contrasting forms works well with the fluffy texture of the aster. Consider companions such as Russian Sage (Perovskia atriplicifolia) for its vertical height and silvery contrast, or low-growing Sedum varieties that function well as groundcovers around the base, thriving in similar sunny, drier conditions.

Design Ideas

White flowers are incredibly versatile in landscape design, offering a cooling contrast during hot months. Use mass plantings of Stokes’ aster to create a substantial drift of white along a walkway, acting as a bright visual path marker. For a contemporary or minimalist design, pair Stokesia laevis ‘Alba’ exclusively with greens and silvers, such as Lamb’s Ears or ornamental grasses, allowing the flower form itself to take center stage without color competition. Its mid-sized stature also makes it perfect for cutting gardens, as the stems rise neatly above the basal foliage for easy harvesting.