Lamiastrum galeobdolon (yellow archangel)

Lamiastrum spp.

Attracts Pollinators Deer Resistant Drought Tolerant Container Friendly

SunPart Shade – Full Shade

HardinessZones 4–9

Overview

Lamiastrum spp. is a genus in the mint family, Lamiaceae, centred on the single species Lamiastrum galeobdolon, yellow archangel, a spreading perennial of European and western Asian woodlands sometimes also placed in Lamium spp.. Plants form low, leafy mats 8-24 inches (20-60 cm) high that spread by rooting runners, with square stems and paired, oval, toothed leaves 1.5-3 inches (4-7.5 cm) long, often marbled or splashed with silver in cultivated forms. In late spring and early summer, whorls of hooded, two-lipped yellow flowers 0.5-0.8 inch (1.3-2 cm) long open in the upper leaf axils, marked with faint brown streaks on the lower lip. The flowers draw bees and other long-tongued insects. Lamiastrum spp. grows quickly in shade and poor soil and roots wherever its runners touch ground, which makes it a fast groundcover but also a plant that can overrun borders and escape into woodland, where it is treated as invasive in parts of North America.

Native Range

Lamiastrum spp. is native to Europe and western Asia, where L. galeobdolon grows in deciduous woodland, hedgerows, and shaded banks on moist, fertile soils. It has naturalised and become invasive in parts of North America and elsewhere, spreading from gardens into damp woodland.

Suggested Uses

Lamiastrum spp. is used as a groundcover under trees and shrubs, on shaded banks, and in difficult dry-shade sites where little else covers the ground. The silver-marked forms add light to dark corners. Its aggressive spread makes it unsuited to small beds or planting near natural woodland, where it can become invasive.

How to Identify

Look for a low, spreading groundcover with square stems and paired, nettle-like toothed leaves, often marked with silver between the veins in cultivated forms. In late spring it carries whorls of hooded yellow flowers in the leaf axils, two-lipped in the manner of dead-nettles. The yellow flowers and silver-marbled leaves on trailing, rooting stems together identify it.

Appearance

Size & Dimensions

Height8" - 2'

Width/Spread2' - 4'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~4 weeks

Spring Summer

Flowering occurs in late spring and early summer, mainly May and June. The whorls of yellow flowers open over a few weeks along the upright shoots. Bloom is lighter in deep shade and heavier where some light reaches the plants.

Detailed Descriptions

Foliage Description

green with silver markings

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Shade

Tolerates up to 4 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 Range5.5 - 7.5(Neutral)

357912

Soil Types

clay loam sand

Drainageaverage

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

1-2 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in part to full shade on moist, average to fertile soils and tolerate dry shade once established. Growth is vigorous, and the runners root quickly to form dense cover, so the plant needs room or a contained bed to keep it in check. It tolerates poor soil, drought, and competition from tree roots better than many groundcovers. Cutting or mowing the mat back after flowering keeps it dense and removes leggy stems. The spreading habit calls for a barrier or regular edging where it borders lawns or natural areas. No winter protection is needed in temperate climates.

Pruning

Shearing or mowing the planting after flowering removes spent stems and tightens the cover. Runners that spread beyond their space can be pulled or cut back at any time in the growing season. Removing stray rooted pieces limits unwanted spread into surrounding ground.

Pruning Schedule

summer