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Calystegia silvatica

large bindweed

Convolvulaceae

Southern Europe, Mediterranean, southwest Asia

Attracts Pollinators Drought Tolerant

SunFull Sun – Part Shade

WaterMedium · drought-tolerant

HardinessZones 5–9

Overview

Calystegia silvatica is a vigorous, twining perennial climber that scrambles 2-4 m (6.5-13 ft) over fences, hedges, and other plants, dying back to the ground each winter. The thin, hairless stems twist anticlockwise and carry arrow-shaped, soft green leaves 5-15 cm (2-6 in) long on long stalks. From early summer it bears large white funnel-shaped flowers 5-9 cm (2-3.5 in) across, each cupped by two large overlapping bracts that hide the sepals, a feature separating it from related bindweeds. It spreads by deep, brittle white rhizomes and root fragments, regrowing from tiny pieces, which makes it a persistent and difficult weed in gardens. A single plant can blanket and pull down shrubs and hedging within a season. Flowers open white and close in dull weather, lasting a day each but produced over many weeks. It grows in almost any soil in sun or light shade and is hard to remove once the root system is established, as severed roots resprout.

Native Range

Calystegia silvatica is native to southern Europe and the Mediterranean, including southeast Europe and southwest Asia. It has naturalised widely across temperate regions and is a common weed of hedgerows, gardens, waste ground, and roadsides. It is not native to North America, where it is grown and has naturalised as a weedy introduction.

Suggested Uses

Rarely planted by choice because of its invasive habit; it appears mostly as a self-introduced weed on fences, hedges, and waste ground. Where tolerated, it gives quick summer screening of large white flowers on supports. In most gardens it is managed as a weed rather than grown as an ornamental.

How to Identify

Identify Calystegia silvatica by its large white funnel-shaped flowers 5-9 cm (2-3.5 in) across and the pair of large, overlapping, inflated bracts that wrap around and conceal the sepals at the flower base. The arrow-shaped leaves have squared or angular basal lobes, and the stems twine anticlockwise. The big bracts and large flowers separate it from the smaller field bindweed Convolvulus arvensis and from hedge bindweed, which has flatter, non-overlapping bracts.

Appearance

Size & Dimensions

Height6'6" - 13'

Width/Spread3' - 6'

Reaches mature size in approximately 2 years

Colors

Flower Colors

white

Foliage Colors

green

Bloom Information

Bloom Period

~14 weeks

Summer Fall

Flowering runs from June to September, sometimes into October. The large white funnels open in the morning and close in dull or wet weather, each lasting about a day. Flowers are produced continuously through the season, with little seed set in cooler regions.

Detailed Descriptions

Foliage Description

Soft green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-12 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 - 8.0(Neutral)

357912

Soil Types

clay loam sand chalk

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

Calystegia silvatica grows in almost any soil in full sun to light shade and needs no encouragement to establish. It climbs by twining and requires host plants, fences, or trellis for support. The plant is hardy and dies back to the rhizome each winter, regrowing strongly in spring. It spreads aggressively by deep, brittle rhizomes that regenerate from fragments, so it is rarely planted deliberately and is usually managed as a weed. Repeated removal of top growth over several seasons weakens the root system, as does careful digging of the white rhizomes. A root barrier limits its spread where it is tolerated.

Pruning

No ornamental pruning is needed. Cut or pull back top growth repeatedly through the season to starve the rhizomes and limit spread. Dig out the white rhizomes as completely as possible, since any fragment left behind will resprout.