The Mexican Sycamore (Platanus mexicana) is an extremely fast-growing, upright shade tree native to northeastern and central Mexico and Guatemala. It is also known as the Mexican plane tree. It has been introduced to other parts of the world, including the United States. In the US, it is found in Texas and Florida, where it grows well as far north as USDA Cold Hardiness Zone 8b.
The tree reaches a mature height of 50 feet in the landscape, with a width of about 30 feet. However, in its natural environment, it can grow up to 80 feet or more. The tree has an upright, rounded crown and is deciduous (sheds its leaves annually). Under ideal conditions, it can grow between 3 to 5 feet per year. As it matures, the trunk can reach a diameter of 1.5 to 3 feet.
This tree has a moderate to long lifespan for a tree, typically living between 50 to 150 years. The tree’s lifespan can be influenced by soil quality, water availability, and susceptibility to diseases or pests. It is adaptable to a variety of soil types, including clay, loam, and sandy soils, provided they are well-drained. It thrives in USDA Hardiness Zones 6 to 9.
Mexican sycamores are very drought tolerant once established, but they’ll perform much better if given plenty of irrigation for about the first 3 years after planting. As with most trees, Mexican sycamore does best in full sun.
The leaves are large, bright green, and have a maple-like shape. The leaves can grow up to 8 inches wide and are palmately veined with three to five main veins. The leaf edge is coarsely toothed between the lobes. The base of the petiole is hollow and covers the winter bud. Undersides of the leaves are covered in soft, white hairs. This feature is particularly prominent on mature trees. The leaves emerge in spring and are shed in late fall or early winter.
The flowers of the Mexican Sycamore are monoecious ( both male and female flowers are found on the same tree). The male flowers are small and clustered, forming spherical, pendulous catkins. They are usually greenish-yellow in color. The female flowers are also small and spherical but tend to be slightly larger than the male flowers. They are greenish and can appear a bit fuzzy due to the presence of tiny hair-like structures. The tree flowers in early spring, usually around March to April, depending on the climate.
After pollination, the female flowers develop into spherical seed balls, often referred to as “syncarps” or “sycamore balls.” These are about 1 to 1.5 inches in diameter. The seed balls mature in late summer to early fall. They then break apart and release small seeds that are dispersed by the wind.
The bark on the younger trunk and large limbs is smooth and greenish-gray or white in color; as the tree ages, the outer bark of limbs and trunk flakes off in irregular, brown patches and exposes the nearly white younger bark beneath. The Mexican Sycamore is sometimes planted as an ornamental in the drier portions of Texas.
USDA Zones
The Mexican Sycamore (Platanus mexicana) is well-suited to USDA Hardiness Zones 7 to 9.
Zone 7:
- Average Minimum Temperature: 0°F to 10°F (-17.8°C to -12.2°C)
- The Mexican Sycamore can tolerate the colder temperatures in this zone, though it may experience some dieback in extreme cold snaps.
Zone 8:
- Average Minimum Temperature: 10°F to 20°F (-12.2°C to -6.7°C)
- Ideal for the Mexican Sycamore, providing the right balance of winter chill and warm summers that the tree thrives in.
Zone 9:
- Average Minimum Temperature: 20°F to 30°F (-6.7°C to -1.1°C)
- The warmer climate of this zone is very favorable, allowing the tree to grow rapidly and maintain its lush appearance year-round.
Common Problems Associted With Growing Mexican Sycamore In The Landscape
- Diseases: It can be affected by diseases such as anthracnose, which causes leaves to curl and turn brown, and bacterial leaf scorch, which can lead to leaf loss and tree decline.
- Pests: The tree is susceptible to pests such as sycamore lace bugs, which feed on the leaves, causing them to look skeletonized and fall off prematurely.
- Environmental Stress: It prefers well-draining soil and can be sensitive to drought or waterlogged conditions. It may also be affected by frost damage in colder climates.
- Cultural Issues: Improper pruning or inadequate spacing can lead to issues such as weak branch structure or increased susceptibility to diseases and pests.
- Urban Pollution: Although it can tolerate urban pollution, it may still suffer from reduced vigor and increased susceptibility to diseases and pests in heavily polluted environments.