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Gomphocarpus physocarpus

balloonplant

Apocynaceae Southern and tropical Africa

Attracts Pollinators Attracts Butterflies Drought Tolerant Container Friendly

SunFull Sun – Part Shade

WaterLow · drought-tolerant

HardinessZones 9–11

Overview

An erect, soft-wooded evergreen shrub reaching 3-6 feet (1-2 m) tall and 2-4 feet (0.6-1.2 m) wide, with milky sap throughout. Leaves narrow and lance-shaped, 2-4 inches (5-10 cm) long and 0.2-0.4 inch (5-10 mm) wide, light green, arranged in opposite pairs. Flowers cream to white, 0.4-0.6 inch (10-15 mm) across, waxy, nodding in rounded clusters. Flowering occurs spring through autumn. Fruit an inflated, pale green bladder-like pod 2-3 inches (5-7.5 cm) wide, covered with soft bristles, splitting to release seeds with silky white floss. Growth is fast and the stems are weakly woody. All parts contain toxic cardiac glycosides and the milky sap irritates skin and eyes. Plants are short-lived, often lasting 2-3 years.

Native Range

Native to southern and tropical Africa. Widely naturalized in warm regions including eastern Australia, where it grows along roadsides, in pastures, and on disturbed ground on a range of soils. It is recorded as an environmental weed in parts of Australia.

Suggested Uses

Planted in butterfly gardens as a larval food plant for wanderer and monarch butterflies, spaced 24-36 inches (60-90 cm) apart. The inflated pods are used in fresh and dried arrangements. Self-seeding and toxicity limit its use near pasture and bushland where it can escape.

How to Identify

Identified by inflated pale green bristly pods 2-3 inches (5-7.5 cm) wide, narrow opposite leaves, and nodding clusters of waxy cream flowers. Broken stems and leaves exude milky sap. The rounded bristly pods separate it from Gomphocarpus fruticosus, which has narrower, more tapered pods.

Appearance

Size & Dimensions

Height3' - 6'

Width/Spread2' - 4'

Reaches mature size in approximately 2 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~20 weeks

Spring Summer Fall

Flowers spring through autumn in warm climates, with peak bloom in summer. Cream flowers hang in rounded clusters and are followed by the inflated pods. Flowering and fruiting often occur together on the same plant. The flowers draw butterflies and other nectar-feeding insects.

Detailed Descriptions

Flower Description

Cream to white

Foliage Description

Light green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 5-9 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

loam sand

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

tender

Time to Maturity

1-2 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Water occasionally; established plants tolerate drought and grow in most soils with reasonable drainage. Grows in full sun to part shade. Self-seeds freely from the floss-borne seeds and can spread into surrounding ground. All parts contain cardiac glycosides toxic to people and livestock, and the milky sap irritates skin and eyes. The plant is a larval host for wanderer and monarch butterflies, whose caterpillars strip the foliage. Plants are short-lived and often replaced every few years.

Pruning

Cut back stems in late winter to encourage bushier regrowth. Remove seed pods before they split to limit self-seeding. The milky sap flows from cut stems and irritates skin. Plants tolerate hard pruning to near ground level.

Pruning Schedule

winter