Posted On: August 29, 2014

London Plane Trees

It’s rare to walk through any park in New York City and not see at least one London Plane tree. These trees have beautiful peeling bark, strange pompom like seeds, and leaves that resemble maple. London Planes account for more than 15% of New York City’s tree populations.

The London plane is actually a cross between the American Sycamore, Platanus occidentalis and the Oriental Plane tree Platanus orientalis. The tree received the name “London Plane” as it was first propagated at the Oxford Botanic Garden. Though long known in New York, the tree was planted sparingly prior to the 1930s. This tree was a favorite of Parks Commissioner Robert Moses who made sure that a London Plane tree was planted in every New York City Park. Prior to 1930 only a few native sycamores existed and even Frederick Law Olmsted only saw the tree suitable as a specimen tree.

London Plane trees Platanus x acerifolia now account for more than 50% of the tree population in Madison Square Park. These beautiful trees are signs left over from an age past. Those frequenting the park may have noticed that fall has appeared to arrive early for us this year and our London Plane trees are the culprit. These trees are susceptible to a leaf fungus that can affect the leaves, twigs, and branches of many species of plane tree. The severity of the disease varies from year-to-year with the various possible symptoms affected by wetness and temperature.

Although moisture is necessary for the spread of the fungus, temperature during early spring is the prime factor in determining how severe the disease will be. If the mean daily temperatures are 50-55 F between bud-break and early leaf emergence, anthracnose will be severe. Our cool, wet spring this year was perfect for the production of anthracnose leaf spores.

While the damage this year may be severe and our London Plane trees are looking a bit bare, there’s nothing to worry about. The new leaves will regrow just fine and trees often produce another crop before fall. Our arborist will also be around to do some pruning on the branches that are showing dieback so that our trees are safe and healthy. Stop by and say hello to our garden crew helping to clean up the early fallen leaves that need to be removed to minimize the affect of leftover spores the following year.