The name “London” gives us an indication that London Plane Sycamore trees are not native of Las Vegas. In fact, Sycamores grow in all states east of the Great Plains, except Minnesota. Sycamores prefer to thrive along edges of streams and lakes and small depressions that have slow drainage. Additionally, this species grows well in wet muck land, shallow peat soils and soils associated with river bottoms and flood plains. Farther south, it commonly grows on the alluvial soils of flood plains adjacent to larger rivers, on former stream banks and in the moist coves, lower slopes and ravines. In general, this tree grows best on sandy loam with a good supply of ground water, typically on the edges of lakes and streams.
So, what happens when you take that same tree and install it in the harsh desert environment with extreme heat, extreme winds, extreme cold and extreme fluctuations in temperatures? Then, on top of that, we plant it in a small tree well next to asphalt and concrete walkways and buildings, like many trees are planted in Las Vegas.
The result can be any or all of the following: discoloration of the leaves (yellowing), leaf scorch (the leaf tips browning), twig die back, lethal cankers, lace bugs, flathead borers, plum borers, premature leaf drop, dead branches, reduced vigor, injury and ultimately death.
While there are some Sycamores that do better than others in the Las Vegas area, this is mainly due to proper tree maintenance being performed on the trees such as, minimal pruning cuts, adequate water, fertilization and overall plant healthcare program.
Environmental stresses are the root (no pun intended) of the problem. Planting London Planes in constricted planters next to asphalt parking lots and being exposed to radiant heat from the buildings, sidewalks, asphalt, cars, exhaust, dry winds, severe cold and heat, and rockscapes are all negative forces that challenge Sycamores to thrive in Las Vegas.
The roots of these trees become super heated and respiration hardly occurs, which thereby prohibits the trees to shut down. As a result, only short periods of time is allowed for the tree to actually transport water and nutrients to the trunk, branches and leaves to the tree.
Now, combine all those environmental stresses with the borers and the lethal canker, which are actually secondary issues and we’ve got some unhealthy London Planes.
In the end, London Planes are challenging to grow in Las Vegas and location of these trees should be carefully considered.
