Sycamore and London Plane Trees

American Sycamore trees (Platanus occidentalis) were commonly established in landscape and roadside settings in the early 1900’s since, like most trees planted at that time, they exhibited quick growth and had large spreading canopies. These newly planted trees grew rapidly and flourished in their planting space until they became too large for the intended site or began to be infected with the anthracnose fungus, a disease that causes early leaf drop, branch dieback, and sometimes the death of the tree.

Once it became evident that sycamore was not an ideal street tree, the London Plane tree (Platanus acerfolia) became more popular as a replacement for the sycamore. The London plane tree is a fertile hybrid between the Oriental plane tree and American sycamore. This hybrid was thought to have developed in the 1600’s when an English gardener planted an American sycamore next to Oriental plane trees in his garden.

Leaf and bark of London plane tree

The London plane tree is somewhat similar in appearance to a sycamore, although its exfoliating bark has a greener cast than the whitish bark of the sycamore. London plane trees also have a more deeply-lobed leaf that looks like a cross between a sycamore and maple leaf. Finally the London plane bears its seed ball clusters in groups of two versus the single cluster of the sycamore. London plane also displays some resistance to sycamore anthracnose; there are varieties developed that are highly resistant to the disease. London plane trees tolerate a wide range of harsh urban conditions so they can be a good choice for landscapes or roadside plantings. These trees grow large so they should not be planted where space is limited, and you should choose cultivars that are resistant to anthracnose.

Article by FCFCDB

Nature Notes for 9/1/2013