1 / 10

Mertensia ciliata

mountain bluebells

Boraginaceae Western United States

Attracts Pollinators Attracts Hummingbirds

Native to North America

SunFull Sun – Part Shade

WaterHigh

HardinessZones 3–7

Overview

Mertensia ciliata is a clump-forming herbaceous perennial in the borage family, native to mountain streamsides and wet meadows of the western United States. Smooth, blue-green oval to lance-shaped leaves 2-6 inches (5-15 cm) long line arching stems that reach 12-48 inches (30-120 cm), with leaf margins fringed by short hairs that give the species its name. The nodding flowers are tubular bells 0.4-0.6 inch (10-15 mm) long, pink in bud and opening to sky-blue, carried in loose terminal clusters that hang from the stem tips. Flowering runs through early to mid summer. The plant grows in consistently moist to wet soils along snowmelt streams and seeps between roughly 6,000 and 11,000 feet (1,800-3,400 m), spreading from a branching rootstock into open colonies. It depends on cool, damp ground; in gardens with dry summers or afternoon heat the foliage yellows and dies back early, leaving bare gaps by August. The species is one element of subalpine riparian communities, where its early nectar supports emerging bumblebees.

Native Range

Native to the mountains of western North America, from British Columbia and Montana south through the Rocky Mountains, Great Basin ranges, and Sierra Nevada to California, Arizona, and New Mexico.

Suggested Uses

Used in streamside plantings, bog gardens, and moist woodland or native meadow settings in cool-summer regions. The early blue flowers draw bumblebees and hummingbirds at a time when few other montane perennials are open. It pairs with other moisture-loving natives where summer irrigation is available.

How to Identify

Identify Mertensia ciliata by its nodding clusters of blue tubular bells that emerge from pink buds, held above smooth, blue-green foliage. Leaves are oval to lance-shaped, 2-6 inches (5-15 cm) long, hairless on the surface but fringed with short hairs along the margins. Arching stems reach 12-48 inches (30-120 cm) and grow in moist montane settings.

Appearance

Size & Dimensions

Height1' - 4'

Width/Spread1' - 2'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~6 weeks

Summer

Flowering occurs from June to August, earlier at lower elevations and later near treeline. Buds open pink and shift to sky-blue as the bells mature, with each loose cluster flowering over two to three weeks. Small nutlets follow and ripen as the stems begin to die back.

Detailed Descriptions

Flower Description

sky-blue, pink in bud

Foliage Description

blue-green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 3-6 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.5(Neutral)

357912

Soil Types

loam silt

Drainagemoist

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

2-3 years

Care & Maintenance

Care Guide

Grows in part shade to full sun where soils stay reliably moist to wet, such as streambanks, bog margins, and irrigated beds. It needs cool root conditions and a near-neutral to slightly acidic pH of 6.0 to 7.5. Hot, dry summers cause early dormancy, so a mulched, shaded position with steady water extends the season. Propagation is by fresh seed, which needs cold stratification, or by careful division of the rootstock in spring. The species has no significant pest problems but rots in soils that dry and rewet sharply. It transplants poorly once established because of its brittle roots.

Pruning

No formal pruning is needed. Yellowing stems can be cut back as the plant enters summer dormancy. Leaving the clump undisturbed protects the brittle rootstock.

✓ Toxicity

Non-toxic