Mexican Bigleaf Magnolia Plant Care

Mexican Bigleaf Magnolia (Magnolia macrophylla var. dealbata) belongs to the Magnoliaceae family within the Magnolia genus. Mexican Bigleaf Magnolia is native to Mexico. Mexican Bigleaf Magnolia is also known as Whitebark Magnolia.

Mexican Bigleaf Magnolia displays a large, deciduous tree growth habit, reaching up to 30 ft tall with a spread of approximately 25 ft. Mexican Bigleaf Magnolia produces large, fragrant flowers in various colors like white, pink, or purple.

Leaf size: approximately 8 inches.

Water a young or newly planted Mexican Bigleaf Magnolia 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.

Mexican Bigleaf Magnolia thrives in full sun to partial shade.

Magnolia macrophylla var. dealbata tolerates temperatures of 0–100°F. Mexican Bigleaf Magnolia prefers humidity levels of 40–70%.

Rich, well-draining soil with plenty of organic matter. Good drainage is essential for Mexican Bigleaf Magnolia to prevent waterlogging, which leads to root rot and fungal issues.

Feed Mexican Bigleaf Magnolia 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 rich, well-draining soil with plenty of organic matter. Avoid low spots where water collects after rain.

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.

Mexican Bigleaf Magnolia can spread to about 25 ft (7.6 m) and reach about 30 ft (9 m) tall. Space plants about 25 ft (7.6 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 Mexican Bigleaf Magnolia 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.

Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.

Young and container-grown trees need extra protection: roots in a pot freeze much more easily than roots in the ground.

Mexican Bigleaf Magnolia can be propagated through seeds, softwood cuttings. Similar propagation techniques also apply to champion's magnolia plant care, which shares the same genus.

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Mexican Bigleaf Magnolia is susceptible to scale insects, aphids, caterpillars. 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.