Solanum dulcamara, bittersweet nightshade
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Vine

Solanum dulcamara

bittersweet nightshade

Solanaceae

Europe, western Asia, northern Africa

At a Glance

TypeVine
HabitClimbing
FoliageDeciduous
Height36-120 inches (90-300 cm)
Width36-96 inches (90-240 cm)

Growing Zones

USDA Hardiness Zones

4 - 9
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
Deer Resistant
Maintenancehigh

Overview

Solanum dulcamara is a scrambling, semi-woody, perennial vine in the nightshade family (Solanaceae) reaching 3–10 feet (0.9–3 m) in height, climbing over fences, shrubs, and other support structures. Stems are semi-woody at the base, herbaceous above, slender, branching, with a slightly woody older growth that persists through winter. Leaves are alternate, ovate with a cordate base, 1–4 inches (2.5–10 cm) long; upper leaves often have 1–2 basal lobes, giving a hastate or trilobed appearance — the lobed upper leaves are a key identification feature. Flowers are purple to violet, star-shaped, 0.4–0.6 inch (10–15 mm) across, with 5 reflexed (swept-back) petals and a protruding cone of 5 bright yellow stamens fused around the style — the reflexed purple petals with the yellow stamen cone are diagnostic for Solanum. Flowers are borne in branching, loose cymes of 10–25. Fruit is an ovoid berry 0.3–0.4 inch (8–10 mm), ripening from green through yellow and orange to bright red; all color stages are often present simultaneously on the same cluster. A single plant produces 1,000–4,000 berries. Contains solanine and solasodine glycoalkaloids; all parts are toxic, with highest concentrations in unripe green berries. Birds consume ripe berries and disperse seeds widely.

Native Range

Native to Europe, western Asia, and northern Africa, occurring in hedgerows, riparian areas, fencerows, woodland edges, and moist disturbed sites from sea level to approximately 6,000 feet (1,800 m). Widely naturalized across the Pacific Northwest, particularly in moist, partially shaded sites.

Suggested Uses

Used in Solanaceae identification courses for teaching the reflexed-petal flower with fused stamen cone (buzz pollination), the berry fruit type, and the glycoalkaloid toxicity. The four-species Solanum comparison (S. dulcamara purple vine red berries, S. nigrum white erect black berries, S. physalifolium white prostrate hairy, S. rostratum yellow spiny) is a standard identification teaching unit. The multicolored berry ripening sequence is studied in fruit pigmentation biology. Toxicity is taught in human and veterinary poisoning.

How to Identify

Distinguished from Solanum nigrum (black nightshade) by the climbing/scrambling vine habit (versus erect annual), the purple (versus white) flowers, the red (versus black) berries, and the often-lobed upper leaves. Distinguished from S. physalifolium (hairy nightshade) by the perennial vine habit (versus prostrate hairy annual) and the purple (versus white) flowers. The reflexed purple petals with the protruding yellow stamen cone, the climbing habit, and the multicolored berry clusters (green through red on the same cluster) are immediately diagnostic.

Appearance

Size & Dimensions

Height3' - 10'
Width/Spread3' - 8'

Colors

Flower Colors

purple
yellow

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~12 weeks
J
F
M
A
M
J
J
A
S
O
N
D
SpringSummerFall
Flowers from May through September. Loose cymes bloom continuously over 10–14 weeks. Pollinated by bees (buzz pollination — bees vibrate the anthers to release pollen from the terminal pore). Berries ripen 6–8 weeks after pollination, with all color stages present simultaneously. In the Pacific Northwest, ripe red berries are conspicuous from July through October.

Detailed Descriptions

Flower Description

Purple with yellow stamen cone

Foliage Description

Dark green, ovate with a cordate base; upper leaves often with 1-2 basal lobes (hastate to trilobed); alternate

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Full Shade
Requires 2-8 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 - 8.0(Neutral)
357912
Soil Types
loamclaysiltsand
Drainage
moist

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

1-2 years

Care & Maintenance

Care Guide

Cutting stems at ground level removes above-ground growth, but the semi-woody base and root crown resprout. Digging the root crown and all lateral roots is necessary for permanent removal. The climbing habit means stems intertwine through fences, shrubs, and trees, complicating removal. Removing before fruiting prevents bird-dispersed seed spread. The berries are a poisoning concern for children due to the bright colors and accessible location on fences and hedges; removal from areas frequented by children is recommended. Gloves should be worn during handling.

Pruning

No pruning applicable in a weed context. Stems are cut at ground level and the root crown is dug. Intertwined stems in fences and hedges are cut at the base and allowed to die before removal to avoid damaging the support structure.

Maintenance Level

high

⚠️ Toxicity Warning

Toxic to pets and humans