Lonicera involucrata (Twinberry)

Botanical name

Lonicera involucrata

Other names

Twinberry, Twinberry honeysuckle, Californian honeysuckle, California honeysuckle, Bearberry honeysuckle , Bracted honeysuckle, Black twinberry

Genus

Lonicera Lonicera

Species

L. involucrata - L. involucrata is a dense, bushy, deciduous shrub with sturdy stems bearing paired, ovate to elliptic, mid- to bright green leaves and, in late spring or early summer, paired, tubular, red-flushed, deep yellow flowers surrounded by large, green bracts turning red with age. Flowers are followed by glossy, spherical, black fruit.

Native to

Western North America

Foliage

Deciduous

Fragrance

Flowers have a light fragrance

Habit

Bushy, Upright

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Colour

Flower

Yellow, Flushed red in Spring; Yellow, Flushed red in Summer

Foliage

Green in Spring; Green in Summer; Green in Autumn

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How to care

Watch out for

Specific pests

Aphids

Specific diseases

Powdery mildew

General care

Pruning

Prune lightly in the first three years. In subsequent years, reduce stems to a pair of strong buds and cutting up to one-fifth of older stems to ground level.

Propagation

Spreads by self-seeding forming large colonies over time.

Propagation methods

Hardwood cuttings, Seed, Softwood cuttings

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Monthly care advice

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Where to grow

Lonicera involucrata (Twinberry) will reach a height of 2m and a spread of 3m after 5-10 years.

Suggested uses

Banks and Slopes, Beds and borders, City, Cottage/Informal, Hedging/Screens, Wildlife

Cultivation

Plant in full sun or partial shade in any moist, well-drained soil. Prefers humus-rich loam. Best planted in full sun in colder climates. Requires two shrubs for better pollination and fruit set.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Acid, Alkaline, Neutral

Light

Partial Shade, Full Sun

Aspect

North, South, East, West

Exposure

Exposed, Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

USDA zones

Zone 10, Zone 9, Zone 8, Zone 7, Zone 6, Zone 5, Zone 4

Defra's Risk register #1

Plant name

Lonicera involucrata (Twinberry)

Common pest name

European cherry fruit fly

Scientific pest name

Rhagoletis cerasi

Type

Insect

Current status in UK

Absent

Likelihood to spread to UK (1 is very low - 5 is very high)

3

Impact (1 is very low - 5 is very high)

4

General biosecurity comments

Fruit fly pest of cherry and honeysuckle; widely distributed in Europe and also present in North America and Asia. No evidence of establishment in the UK to date despite repeated interceptions; but honeysuckle and cherry growers may wish to be aware and monitor for its presence.

About this section

Our plants are under greater threat than ever before. There is increasing movement of plants and other material traded from an increasing variety of sources. This increases the chances of exotic pests arriving with imported goods and travellers, as well as by natural means. Shoot is working with Defra to help members to do their part in preventing the introduction and spread of invasive risks.

Traveling or importing plants? Please read "Don't risk it" advice here

Suspected outbreak? Click here for contact details to report to the relevant authority.

Date updated: 7^th March 2019 For more information visit: https://planthealthportal.defra.gov.uk/