Physocarpus opulifolius 'Monlo', Diabolo® ninebark
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Deciduous Shrubs

Physocarpus opulifolius 'Monlo'

Diabolo® ninebark

Rosaceae

Cultivar of Physocarpus opulifolius, native to eastern North America from Quebec south to Georgia and west to Kansas and Colorado, along stream banks and forest edges

At a Glance

TypeShrub
HabitMounding
FoliageDeciduous
Height6–9 feet (1.8–2.7 m)
Width6–8 feet (1.8–2.4 m)
Maturity4 years

Growing Zones

USDA Hardiness Zones

3 - 7
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Attracts Butterflies
Deer Resistant
Drought Tolerant
Native to North America
Maintenancelow

Overview

A large, mounding deciduous shrub reaching 6–9 feet (1.8–2.7 m) tall and 6–8 feet (1.8–2.4 m) wide, a cultivar of P. opulifolius (eastern ninebark) selected for deep burgundy-purple foliage — one of the most intensely dark-foliaged large shrubs commonly grown in the Pacific Northwest. Leaves three-lobed, 1.5–3 inches (4–7.5 cm) long, deep burgundy-purple through the growing season in full sun. In June, dense corymbs of small pinkish-white flowers appear against the dark foliage. Reddish papery seed capsules persist through fall and winter. Bark exfoliates on mature stems, revealing cinnamon-brown inner layers. A cultivar of a native eastern North American species. Extremely adaptable and low-maintenance. Hardy in USDA zones 3–7.

Native Range

Physocarpus opulifolius is native to eastern North America from Quebec south to Georgia and west to Kansas and Colorado, growing along stream banks, forest edges, and disturbed areas. 'Monlo', sold under the trade name Diabolo®, is a cultivar selected for its deep burgundy-purple foliage.

Suggested Uses

Planted as a bold specimen, large screening shrub, or mixed border backdrop at 6–8 foot (1.8–2.4 m) spacing. The deep burgundy-purple foliage provides season-long contrast against green or silver-foliaged companions. Effective with golden-foliaged shrubs, silver ornamental grasses, or yellow-flowered perennials. The native North American species background makes Physocarpus opulifolius 'Monlo' a durable and ecologically appropriate choice for Pacific Northwest landscapes.

How to Identify

Identified by the large mounding habit with three-lobed leaves 1.5–3 inches (4–7.5 cm) long in deep burgundy-purple (in full sun), dense corymbs of small pinkish-white flowers in June, reddish papery seed capsules, and exfoliating bark on mature stems revealing cinnamon-brown layers. Distinguished from Sambucus nigra 'Black Beauty' by the alternate (not opposite) lobed leaves and exfoliating bark; from Cotinus coggygria 'Royal Purple' by the lobed leaves and exfoliating bark vs. rounded unlobed leaves and fluffy plumes; from other Physocarpus cultivars by the depth of burgundy-purple foliage.

Appearance

Size & Dimensions

Height6' - 9'
Width/Spread6' - 8'

Reaches mature size in approximately 4 years

Colors

Flower Colors

white
pink

Foliage Colors

purple
burgundy

Fall Foliage Colors

burgundy
orange

Bloom Information

Bloom Period

~3 weeks
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Summer
Blooms in June for approximately 2–3 weeks. Dense corymbs 1.5–2 inches (4–5 cm) across of small pinkish-white flowers at branch tips, attractive against the dark foliage. Followed by reddish, inflated, papery seed capsules that persist through fall and into winter.

Detailed Descriptions

Flower Description

Pinkish-white, small, in dense corymbs 1.5–2 inches (4–5 cm) across at branch tips in June

Foliage Description

Three-lobed, 1.5–3 inches (4–7.5 cm) long, deep burgundy-purple in full sun (fades to greenish-purple in shade)

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Requires 5-10 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
clayloamsand
Drainage
well drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

3–5 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant in full sun for the best and most intense foliage color — in shade, foliage fades to greenish-purple. Adaptable to clay, loam, or sand; tolerates wide pH range. Space 6–8 feet (1.8–2.4 m) apart. Water regularly during establishment; drought tolerant once established. Extremely adaptable — tolerates urban conditions, compacted soils, and seasonal flooding. Virtually pest- and disease-free. Remove any all-green reversion shoots immediately to preserve foliage character.

Pruning

Prune immediately after flowering (late June–July) to control size and encourage vigorous new growth with the best foliage color. One-third renewal pruning annually — removing the oldest stems to the ground — maintains a healthy productive shrub. Can be cut back hard (to 12–18 inches/30–45 cm) in late winter to fully rejuvenate, sacrificing one season's bloom. Remove all-green reversion shoots at the base as soon as they appear.

Pruning Schedule

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summerearly spring

Maintenance Level

low

⚠️ Toxicity Warning

Non-toxic
Physocarpus opulifolius 'Monlo' (Diabolo® ninebark) - Identification & Care Guide | PlantRef