Tree of the Month: London Plane Tree
The London Plane Tree
A hybrid of two types of sycamore trees, the London plane was popularized in and originally distributed from its namesake city, being an urban tree through and through. Its robust and hardy nature makes this tree a great choice for Nashville streets and neighborhoods, where a London plane will thrive in the built environment.
This Hybrid’s History
The London plane (Platanus x acerifolia) is a hybrid of two sycamore species; the American sycamore (Platanus occidentalis), native to Eastern and Central North America, and the Oriental sycamore (Platanus orientalis), which is native to Eastern Europe and Western Asia. While the exact origin of the hybrid is uncertain, with some sources citing Spain, southern France, and England, one thing is certain: the tree became well-known from the 17th century and beyond, being widely planted in garden-loving London before and throughout the industrial revolution, where it tolerated the smoky air of the city. Today, it’s still one of the most common trees found around London.
In addition to its tolerance of pollution, there are many reasons this species is a popular urban tree. It’s a big, leafy shade tree that can deal with heat, drought, and restricting ground conditions. It’s also a visually appealing tree, with a unique, multicolored bark pattern that gives the tree an interesting look throughout the year.
Characteristics of a London Plane Tree
The large leaves of a London Plane are one of its main draws since they cast lots of shade throughout the spring and summer months. The species’ scientific name, acerifolia, refers to the similarity of these leaves to those of a maple: the London plane has three to five pointed lobes on their broad leaves that resemble those of the genus Acer. However, the London plane’s lobes may have serrated edges. In the fall, their foliage turns an orange-to-bronze color before dropping for the winter.
Even without its leaves, a London plane has particular visual interest. The tree’s papery bark sheds unevenly to expose the younger bark underneath, resulting in a camouflage pattern of gray, beige, and olive that is distinctive to the tree. This exfoliating habit is one of the reasons the tree survives so well in polluted air! By regularly dropping bark that has absorbed pollutants that would otherwise congest the pores and prevent oxygen from reaching the trunk, the tree refreshes its outer layers to be able to breathe. This means the tree helps filter air pollutants by both its bark and leaves!
The seeds of the London plane look like fuzzy Christmas ornaments, adding to the tree’s overall unique appearance. They grow as small spheres that hang in pairs from the branches, containing fluffy seeds that can be carried by the wind. Their buttonball seeds begin as green in the spring, then turn into a brown color as they mature over the year, falling in autumn or winter.
One of the reasons the London plane does so well in cities is that it doesn’t have a hard preference for the soil type or pH. It does just fine in acidic or alkaline soil (between 5 and 8 pH) and doesn’t mind compacted or clay-heavy soil (although it does best in loam). While it doesn’t like water-logged ground, it will do well in moist soil but can also tolerate some drought and heat. In general, the London plane is tolerant of most site conditions.
How Fast Does a London Plane Tree Grow?
London plane trees are fast growers, and once they settle in after being planted, they can gain multiple feet per year in height, reaching 70-100 feet tall at maturity. They are also a long-lived species that can live up to 200 years. This fast growth rate, coupled with longevity, make the London plane a great city tree since it will be able to perform the ecosystem services, like shade provision and pollution filtration, that are performed best by big, mature trees.
London Planes vs. Traditional Sycamores
There are a few ways to distinguish a London Plane from another type of sycamore:
If it’s growing in a city, it’s likely a London plane! Due to the sycamore’s leaf issues with anthracnose, which can devastate a regular sycamore tree, the anthracnose-resistant London plane is more often planted in cities to ensure their long-term health and effectiveness.
London plane trees tend to have more green in their trunks compared to other sycamores, which tend to have more white-colored inner bark.
While the American sycamore usually grows one seed per stalk, the London plane’s seeds usually grow in groups of two, and the Oriental sycamore grows its seeds in groups of three or more.
London Plane Tree Pros and Cons
There are many pros and a few cons to the London plane tree, especially in cities!
Pros:
Fast growers
Long-lived
Like full sun and open spaces
Tolerate heat and drought
They do fine in compacted soils that are acidic or alkaline
Tolerant of air pollution
Resistant to anthracnose and pest problems
Cons:
The fuzzy seeds and regularly shedding bark can be messy
Their tall, wide crowns may prevent them from being grown in tight spaces (although some cultivars grow with tighter crowns and are more flexible in this regard)
The London plane was born to be an urban tree. With many upsides and few challenges, this tree is an excellent choice to be planted in any Nashville yard or along a street or walkway. If you’re looking to purchase one for your own space, check out the London planes available through the Nashville Tree Conservation Corps’ annual tree sale from October through February. If you can’t plant a tree but want to participate in caring for our neighborhood canopies, you can volunteer with us by signing up on our website here. And for ongoing information on trees and caring for them around Nashville, subscribe to our newsletter!