Swamp Milkweed Plant Care

Swamp Milkweed (Tabernaemontana palustris) belongs to the Apocynaceae family within the Tabernaemontana genus. Swamp Milkweed is native to Northern Brazil, Colombia, and Venezuela. Swamp Milkweed is also known as Marsh Milkweed.

Swamp Milkweed displays an upright, bushy shrub growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Swamp Milkweed produces fragrant white flowers in clusters.

Leaf size: approximately 5 inches.

Water a young or newly planted Swamp Milkweed every 7–10 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Swamp Milkweed thrives in bright indirect light. Avoid placing Swamp Milkweed in direct, harsh sunlight for extended periods, as this can scorch the foliage.

Tabernaemontana palustris tolerates temperatures of 65–80°F. Swamp Milkweed prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Well-draining, fertile soil with added perlite for extra drainage. Good drainage is essential for Swamp Milkweed to prevent waterlogging, which leads to root rot and fungal issues.

Feed Swamp Milkweed every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with bright indirect light and well-draining, fertile soil with added perlite for extra drainage. Avoid low spots where water collects after rain.

Swamp Milkweed is suited to USDA Zone 11a – 12b.

Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.

Swamp Milkweed can spread to about 2 ft (0.6 m) and reach about 3 ft (1 m) tall. Space plants about 2 ft (0.6 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the plant spacing calculator.

Prune Swamp Milkweed while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.

Swamp Milkweed is frost-tender (hardy to USDA zone 11). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Swamp Milkweed can be propagated through stem cuttings, air layering. Similar propagation techniques also apply to african dogwood plant care, which shares the same genus.

See all plants toxic to cats and plants toxic to dogs.

Swamp Milkweed is susceptible to aphids, spider mites, mealybugs. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Swamp Milkweed grows outdoors in USDA Zone 11a – 12b. It survives winters down to planting zone 11a. Swamp Milkweed is native to Northern Brazil, Colombia, and Venezuela. In cooler regions, grow Swamp Milkweed as a houseplant or bring it indoors before the first frost.