Grandiflora Stewartia Plant Care

Grandiflora Stewartia (Stewartia grandiflora) belongs to the Theaceae family within the Stewartia genus. Grandiflora Stewartia is native to Japan and Korea.

Grandiflora Stewartia displays a small to medium-sized tree growth habit, reaching up to 30 ft tall with a spread of approximately 20 ft. Grandiflora Stewartia produces large, showy white flowers with yellow stamens.

Leaf size: approximately 4 inches.

Water a young or newly planted Grandiflora Stewartia every 7–10 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.

Grandiflora Stewartia thrives in partial shade to full sun.

Stewartia grandiflora tolerates temperatures of 50–80°F. Grandiflora Stewartia prefers humidity levels of 40–70%.

Moist, well-draining acidic soil with high organic content. Good drainage is essential for Grandiflora Stewartia to prevent waterlogging, which leads to root rot and fungal issues.

Feed Grandiflora Stewartia 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 partial shade to full sun and moist, well-draining acidic soil with high organic content. Avoid low spots where water collects after rain.

Grandiflora Stewartia is suited to USDA Zone 12a.

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.

Grandiflora Stewartia can spread to about 20 ft (6.1 m) and reach about 30 ft (9 m) tall. Space plants about 20 ft (6.1 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 Grandiflora Stewartia 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.

Grandiflora Stewartia is frost-tender (hardy to USDA zone 12). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Grandiflora Stewartia can be propagated through seeds, semi-hardwood cuttings. Similar propagation techniques also apply to japanese stewartia plant care, which shares the same genus.

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

Grandiflora Stewartia is susceptible to aphids, scale insects, spider mites. 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.

Grandiflora Stewartia grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Grandiflora Stewartia is native to Japan and Korea. In cooler regions, grow Grandiflora Stewartia as a houseplant or bring it indoors before the first frost.