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Key characteristics

Family: Lamiaceae
Height: 36 to 48 inches
Width: 18 to 24 inches
Flower color: Violet to lavender tubular flowers
Foliage color: Bright green leaves with serrated edges
Bloom time: Late summer to early fall
Light: Partial shade to full shade
Water: Moderate
Maintenance: Low; occasional pruning after flowering for shape, and mulching to retain soil moisture
Growing zone: Zones 5-8
Wildlife: Attracts pollinators, including bees and butterflies

Perennials

Isodon longitubus

Heavenly Teacost

Isodon longitubus is a late-blooming perennial that showcases tubular flowers in shades of pale violet to lavender-blue, arranged along arching stems. The blooms appear in clusters from late summer into autumn, adding a subtle charm to the garden during the transition from warm to cooler weather. The flowers' elegant, elongated shape and soft coloration make them a delicate and graceful addition to the landscape.

Native to Japan, Isodon longitubus thrives in woodland and shaded environments, where its understated beauty complements other shade-loving plants. Its ability to bloom late in the season makes it an excellent choice for extending garden interest into autumn.

Light

Partial shade to full shade

Water

Moderate

Bloom time

Late summer to early fall

Find this plant

Works well in

Borders
Shade Gardens
Woodland Gardens
Pollinator Gardens
Cut Flower Gardens

Companion plants

Siberian bugloss · Sweet woodruff · Foamflowers · Epimediums · Hostas · Bleeding hearts

Design tip

Late flowers extend the season, so set it behind or beside plants that finish in midsummer. Keep it out of hot afternoon sun and layer it with woodland companions for a full, settled look.