Sandwich Island Lobelia Plant Care

Sandwich Island Lobelia (Bobea sandwicensis) belongs to the Rubiaceae family within the Bobea genus. Sandwich Island Lobelia is native to Hawaiʻi. Sandwich Island Lobelia is also known as Sandwich Island Bellflower.

Sandwich Island Lobelia displays a bushy shrub or small tree growth habit, reaching up to 6 ft tall with a spread of approximately 4 ft. Sandwich Island Lobelia produces small, fragrant white or pink flowers in clusters.

Leaf size: approximately 4 inches.

Water a young or newly planted Sandwich Island Lobelia 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.

Sandwich Island Lobelia thrives in partial shade to full sun.

Bobea sandwicensis tolerates temperatures of 60–80°F. Sandwich Island Lobelia prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Well-draining, slightly acidic soil with organic matter. Good drainage is essential for Sandwich Island Lobelia to prevent waterlogging, which leads to root rot and fungal issues.

Feed Sandwich Island Lobelia 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 well-draining, slightly acidic soil with organic matter. Avoid low spots where water collects after rain.

Sandwich Island Lobelia is suited to USDA Zone 13a.

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.

Sandwich Island Lobelia can spread to about 4 ft (1.2 m) and reach about 6 ft (2 m) tall. Space plants about 4 ft (1.2 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 Sandwich Island Lobelia 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.

Sandwich Island Lobelia is frost-tender (hardy to USDA zone 13). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Sandwich Island Lobelia can be propagated through seeds, stem cuttings. Similar propagation techniques also apply to bobea timonioides plant care, which shares the same genus.

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

Sandwich Island Lobelia 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.

Sandwich Island Lobelia grows outdoors in USDA Zone 13a. It survives winters down to planting zone 13a. Sandwich Island Lobelia is native to Hawaiʻi. In cooler regions, grow Sandwich Island Lobelia as a houseplant or bring it indoors before the first frost.