Vietnamese Alstonia Plant Care

Vietnamese Alstonia (Alstonia annamensis) belongs to the Apocynaceae family within the Alstonia genus. Vietnamese Alstonia is native to Cambodia and Vietnam.

Vietnamese Alstonia displays a tall, upright tree growth habit, reaching up to 30 ft tall with a spread of approximately 15 ft. Vietnamese Alstonia produces small, fragrant white flowers in clusters.

Leaf size: approximately 6 inches.

Water a young or newly planted Vietnamese Alstonia every 7–14 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Vietnamese Alstonia thrives in full sun to partial shade.

Alstonia annamensis tolerates temperatures of 60–85°F. Vietnamese Alstonia prefers humidity levels of 50–80%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Well-draining loamy soil with added organic matter for moisture retention. Good drainage is essential for Vietnamese Alstonia to prevent waterlogging, which leads to root rot and fungal issues.

Feed Vietnamese Alstonia every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees 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 full sun to partial shade and well-draining loamy soil with added organic matter for moisture retention. Avoid low spots where water collects after rain.

Vietnamese Alstonia is suited to USDA Zone 10b – 12b.

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

Vietnamese Alstonia can spread to about 15 ft (4.6 m) and reach about 30 ft (9 m) tall. Space plants about 15 ft (4.6 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 tree spacing calculator.

Prune Vietnamese Alstonia 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 tree in one year.

Vietnamese Alstonia is frost-tender (hardy to USDA zone 10). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Vietnamese Alstonia can be propagated through seeds, stem cuttings.

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

Vietnamese Alstonia is susceptible to aphids, scale insects, 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.

Vietnamese Alstonia grows outdoors in USDA Zone 10b – 12b. It survives winters down to planting zone 10b. Vietnamese Alstonia is native to Cambodia and Vietnam. In cooler regions, grow Vietnamese Alstonia as a houseplant or bring it indoors before the first frost.