Moltkia spp.

Mediterranean region and western Asia

Attracts Pollinators Drought Tolerant Container Friendly

HardinessZones 5–8

Overview

Moltkia spp. is a small genus of about six perennial herbs and low subshrubs in the borage family (Boraginaceae), native to the Mediterranean region and western Asia. Plants form low, woody-based mounds 6-18 inches (15-45 cm) tall and 12-18 inches (30-45 cm) wide, with narrow, stiff, hairy leaves crowded along the stems. Funnel- to tube-shaped flowers appear in coiled clusters in late spring and summer, colored blue to violet in Moltkia petraea and yellow in Moltkia suffruticosa, each flower 0.3-0.5 inch (8-12 mm) long. The hairy foliage and rough texture are typical of the family. Native to sunny limestone rock and dry slopes, the genus needs sharp drainage and full sun and is intolerant of heavy, wet soils, which rot the woody base. Several species are grown in rock gardens, where they stay compact and slow-growing.

Native Range

Moltkia spp. is native to the Mediterranean region and western Asia, from Italy and the Balkans through Greece and Turkey to Iran. Species grow on dry, sunny limestone rock, screes, and stony slopes.

Suggested Uses

Used in rock gardens, raised beds, crevice gardens, and dry stone walls where drainage is sharp and sun is full. Suited to alpine troughs and gravel plantings in regions with dry summers. The low, mounded habit sits among other small Mediterranean rock plants.

How to Identify

Identified by low, woody-based plants with narrow, bristly-hairy leaves and coiled clusters of funnel-shaped flowers in blue, violet, or yellow. The flowers and rough, hairy foliage place it in the borage family, while the subshrubby base and rock-garden stature separate it from related Lithodora spp.. Flower color helps distinguish the blue-flowered from the yellow-flowered species.

Appearance

Size & Dimensions

Height6" - 1'6"

Width/Spread1' - 1'6"

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~6 weeks

Spring Summer

Flowering occurs in late spring and early summer, roughly May to July, with the coiled flower clusters opening in sequence over several weeks. Some plants carry scattered later blooms in cooler summers. The flowers fade to give small nutlet fruits.

Detailed Descriptions

Flower Description

Blue to violet or yellow

Foliage Description

Green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 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 Range6.5 - 8.0(Alkaline)

357912

Soil Types

rocky chalk sand

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

2-3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Grow in full sun on gritty, sharply drained, neutral to alkaline soil, often with a limestone component. The genus tolerates heat and drought once established but rots in heavy or wet ground, especially over winter. A position among rocks or in a raised bed keeps the woody base dry. Propagation is by seed or by soft cuttings taken in summer. Plants are slow to bulk up and respond to minimal disturbance. Cold, wet winters are the main limit on where the genus can be grown.

Pruning

Trim lightly after flowering to keep the mound dense and to remove spent flower clusters. Cutting into old bare wood resprouts slowly, so trimming is kept to younger growth. No hard pruning is needed.