Lonicera involucrata, twinberry honeysuckle
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Deciduous Shrubs

Lonicera involucrata

twinberry honeysuckle

Caprifoliaceae

Alaska south through BC, Washington, Oregon to California; east to Rocky Mountains and Great Lakes; moist stream banks, wetland edges, and forest edges

At a Glance

TypeShrub
HabitUpright
FoliageDeciduous
Height4-10 feet (1.2-3 m)
Width4-8 feet (1.2-2.4 m)
Maturity6 years

Growing Zones

USDA Hardiness Zones

3 - 9
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
Zone 9
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Attracts Butterflies
Attracts Hummingbirds
Native to North America
Maintenancevery low

Overview

An upright, multi-stemmed deciduous shrub in the family Caprifoliaceae, native to moist stream banks, wetland edges, forest edges, and cool moist thickets from Alaska south through British Columbia, Washington, and Oregon to California, and east to the Rocky Mountains and Great Lakes. The specific epithet involucrata means 'with involucre,' referring to the two pairs of prominent bracts that subtend and ultimately frame the paired fruits. Plants grow 4–10 feet (1.2–3 m) tall with opposite, broadly oval to ovate, bright green leaves 2–5 inches (5–13 cm) long. From May through August, pairs of tubular, pale to golden-yellow flowers 0.5–0.8 inch (12–20 mm) long emerge from each leaf axil, subtended by two pairs of oval bracts that enlarge and turn deep red-purple as the twin glossy black berries develop. The showy bracted twin black berries are the single most distinctive identification feature. Flowers attract hummingbirds and native bees; berries are consumed by dozens of bird species. Berries are mildly toxic to humans in quantity.

Native Range

Native to moist stream banks, wetland edges, forest edges, and cool moist thickets from Alaska south through British Columbia, Washington, and Oregon to California, and east to the Rocky Mountains and Great Lakes.

Suggested Uses

Planted as a wildlife habitat shrub, rain garden feature, or stream bank planting at 4–6 foot (1.2–1.8 m) spacing. Outstanding combined hummingbird, pollinator, and bird value. Combines with Cornus sericea, Salix species, and Carex obnupta in moist native plantings.

How to Identify

Identified by upright shrub habit 4–10 feet (1.2–3 m) with opposite, broadly oval, pointed bright green leaves 2–5 inches (5–13 cm). Diagnostic feature: paired glossy black berries framed by two pairs of enlarged, deep red to red-purple bracts — involucrata means 'with involucre.' From May–August, pairs of pale to golden-yellow tubular flowers at each leaf axil are subtended by the same bracts, which are green at bloom but enlarge and deepen as fruits develop. Bracted paired black berries in late summer are unmistakable.

Appearance

Size & Dimensions

Height4' - 10'
Width/Spread4' - 8'

Reaches mature size in approximately 6 years

Colors

Flower Colors

yellow

Foliage Colors

green

Fall Foliage Colors

yellow

Bloom Information

Bloom Period

~10 weeks
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SpringSummer
Blooms May through August for 6–10 weeks, producing pairs of tubular, pale to golden-yellow flowers at each leaf axil. Flowers attract hummingbirds, native bumblebees, and butterflies. By late summer the bracts deepen to red-purple, framing twin glossy black berries consumed by waxwings, thrushes, grouse, robins, and bears.

Detailed Descriptions

Flower Description

pale to golden yellow; tubular pairs 0.5–0.8 inch at each leaf axil; May–August; bracts enlarge to deep red-purple framing twin glossy black berries — most diagnostic feature

Foliage Description

bright green; opposite broadly oval to ovate with pointed tips, 2–5 inches

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Requires 3-8 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 Range5.0 - 7.5(Neutral)
357912
Soil Types
loamclaysilt
Drainage
moist

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

4-6 years

Care & Maintenance

Care Guide

Plant in full sun to partial shade in moist to wet, acidic to neutral soil with a pH of 5.0–7.5. Tolerates seasonally saturated soils. Adaptable to rain gardens, pond margins, and moist woodland borders. No fertilizer needed.

Pruning

Remove dead or crossing stems to the base in late winter. Thin oldest canes every few years to maintain vigor. Can be cut back hard in late winter for full rejuvenation.

Pruning Schedule

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early spring

Maintenance Level

very low

⚠️ Toxicity Warning

Toxic to humans
Lonicera involucrata (twinberry honeysuckle) - Identification & Care Guide | PlantRef