Jerusalem Thorn Plant Care

Jerusalem Thorn (Parkinsonia praecox) belongs to the Fabaceae family within the Parkinsonia genus. Jerusalem Thorn is native to the dry Neotropics from Mexico to Argentina. Jerusalem Thorn is also known as Retama, Green Palo Verde.

Jerusalem Thorn displays a spreading, thorny tree growth habit, reaching up to 20 ft tall with a spread of approximately 20 ft. Jerusalem Thorn produces bright yellow, fragrant flowers in clusters.

Leaf size: approximately 2 inches.

Water a young or newly planted Jerusalem Thorn 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.

Jerusalem Thorn thrives in full sun.

Parkinsonia praecox tolerates temperatures of 50–100°F. Jerusalem Thorn prefers humidity levels of 10–60%.

Well-draining sandy soil with low fertility. Good drainage is essential for Jerusalem Thorn to prevent waterlogging, which leads to root rot and fungal issues.

Feed Jerusalem Thorn every 8 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 and well-draining sandy soil with low fertility. Avoid low spots where water collects after rain.

Jerusalem Thorn 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.

Jerusalem Thorn can spread to about 20 ft (6.1 m) and reach about 20 ft (6 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 Jerusalem Thorn 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.

Jerusalem Thorn 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.

Jerusalem Thorn can be propagated through seeds. Similar propagation techniques also apply to palo verde plant care, which shares the same genus.

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Jerusalem Thorn is susceptible to aphids, 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.

Jerusalem Thorn grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Jerusalem Thorn is native to the dry Neotropics from Mexico to Argentina. In cooler regions, grow Jerusalem Thorn as a houseplant or bring it indoors before the first frost.