Coulter's lignum vitae Plant Care

Coulter's lignum vitae (Guaiacum coulteri) belongs to the Zygophyllaceae family within the Guaiacum genus. Coulter's lignum vitae is native to western Mexico and Guatemala. Coulter's lignum vitae is also known as Mexican lignum vitae, Guayacan.

Coulter's lignum vitae displays a slow-growing small tree growth habit, reaching up to 15 ft tall with a spread of approximately 10 ft. Coulter's lignum vitae produces small blue to purple flowers.

Leaf size: approximately 3 inches.

Water a young or newly planted Coulter's lignum vitae every 10–14 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.

Coulter's lignum vitae thrives in full sun.

Guaiacum coulteri tolerates temperatures of 65–85°F. Coulter's lignum vitae prefers humidity levels of 40–60%.

Well-draining sandy soil mix with good aeration. Good drainage is essential for Coulter's lignum vitae to prevent waterlogging, which leads to root rot and fungal issues.

Feed Coulter's lignum vitae 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 mix with good aeration. Avoid low spots where water collects after rain.

Coulter's lignum vitae is suited to USDA Zone 13b.

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.

Coulter's lignum vitae can spread to about 10 ft (3 m) and reach about 15 ft (5 m) tall. Space plants about 10 ft (3 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 Coulter's lignum vitae 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.

Coulter's lignum vitae 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.

Coulter's lignum vitae can be propagated through seeds, stem cuttings. Similar propagation techniques also apply to lignum vitae plant care, which shares the same genus.

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Coulter's lignum vitae is susceptible to spider mites, 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.

Coulter's lignum vitae grows outdoors in USDA Zone 13b. It survives winters down to planting zone 13b. Coulter's lignum vitae is native to western Mexico and Guatemala. In cooler regions, grow Coulter's lignum vitae as a houseplant or bring it indoors before the first frost.