Milkweed Plant

Balloon milkweed (Gomphocarpus physocarpus) is a shrubby milkweed from southern Africa, grown for its airy stems, small pale flowers, and inflated, spiny seed pods. It is a tender perennial in warm climates and is often grown as a summer annual where winters are cold. ## Growth and Garden Use Plants typically reach 4–6 feet tall and 2–3 feet wide, with narrow light green leaves and a vase-shaped form. The small white flowers, often touched with pink, appear in summer; the rounded greenish-yellow pods are the showiest feature and turn tan as they mature. [North Carolina Extension](https://plants.ces.ncsu.edu/plants/gomphocarpus-physocarpa/common-name/balloon-milkweed/) lists the plant for full sun, well-drained sandy or loamy soil, and USDA Zones 8–10. It can be used toward the back of a border or in a roomy container. ## Wildlife and Seasonal Interest The foliage is a host for monarch and other Danaus caterpillars, while flowers attract butterflies and other pollinators. The pods split to release silky seeds in fall, and stems with pods can be used in floral arrangements. The accepted name is [Gomphocarpus physocarpus at Kew](https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:97670-1); some extension and nursery references use the related spelling *physocarpa*. ## Maintenance Grow in sun and avoid persistently wet soil. Once established, the plant tolerates dry spells and heat, but water during prolonged dry weather to support flowering and pod formation. Handle broken stems carefully because the milky sap can irritate skin and eyes.