Yellow kowhai Plant Care

Yellow kowhai (Sophora tomentosa) belongs to the Fabaceae family within the Sophora genus. Yellow kowhai is native to coastal conditions and near wetlands. Yellow kowhai is also known as Coastal kowhai, Silver bush, Necklace pod.

Yellow kowhai displays an upright, spreading tree growth habit, reaching up to 30 ft tall with a spread of approximately 20 ft. Yellow kowhai produces clusters of pea-like flowers in shades of white, pink, or purple.

Leaf size: approximately 6 inches.

Water a young or newly planted Yellow kowhai 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.

Yellow kowhai thrives in full sun to partial shade.

Sophora tomentosa tolerates temperatures of 50–85°F. Yellow kowhai prefers humidity levels of 40–70%.

Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Yellow kowhai to prevent waterlogging, which leads to root rot and fungal issues.

Feed Yellow kowhai 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 compost for nutrients. Avoid low spots where water collects after rain.

Yellow kowhai 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.

Yellow kowhai 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 Yellow kowhai 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.

Yellow kowhai 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.

Yellow kowhai can be propagated through seeds, softwood cuttings. Similar propagation techniques also apply to fernandez sophora plant care, which shares the same genus.

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Yellow kowhai is susceptible to aphids, caterpillars, scale insects. 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.

Yellow kowhai grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Yellow kowhai is native to coastal conditions and near wetlands. In cooler regions, grow Yellow kowhai as a houseplant or bring it indoors before the first frost.