The American sycamore is a deciduous tree that grows 75 to 100 feet tall—the largest deciduous tree in North America. It's easily identified by its mottled bark. The outer bark is brown and peels away from the trunk to reveal a lighter-colored inner bark. The leaves are large (4 to 10 inches across), are divided into 3 or 5 lobes, and have coarsely-toothed edges. Another distinguishing feature is the seed pod, which takes the form of a fuzzy, globular ball (1.5 inches across). Despite its beauty, fast growth rate, and pollution-tolerance, it doesn't make a good street tree due to its messiness. But, if you wish to grow it, the best time to plant one is late winter or early spring.
|Common Names||Sycamore, American sycamore, buttonball tree, buttonwood, western planetree, American planetree|
|Botanical Name||Platanus occidentalis|
|Plant Type||Deciduous tree|
|Mature Size||75 to 100 feet tall|
|Sun Exposure||Full to partial sun|
|Soil Type||Well-drained, consistently moist|
|Soil pH||5.0 to 8.0 (not fussy about soil pH)|
|Hardiness Zones||4 to 9, USDA|
|Native Area||Eastern North America|
Sycamore Tree Care
Because it grows along streams in the wild, sycamore tolerates wet areas better than many trees. It also tolerates the air pollution often found in urban settings. But it's a high-maintenance plant, thanks to its messy seed pods, giving you the added work of having to rake the seed pods up and dispose of them. Make sure you have lots of space wherever you are going to plant this tree, because they are enormous when fully grown.
Grow sycamore tree in full sun for best results, although it does tolerate some shade.
Give it good drainage. An average garden loam is sufficient.
For best results, keep its soil evenly moist.
Temperature and Humidity
Adaptable to a wide range of climates (zones 4 to 9), sycamore isn't troubled by humidity and performs equally well in cold and warmer climates.
Sycamore isn't a heavy feeder. Fertilize it with a complete fertilizer in early spring for an extra boost. Follow instructions on the package closely, as they'll detail how much fertilizer to use based on tree size. Failure to follow instructions can result in over-fertilizing and possibly burning your plant.
Types of Sycamore Trees (Planetrees)
Platanus occidentalis is one of the parents (the other being Platanus orientalis) of that popular hybrid, London planetree (Platanus × acerifolia). The species name refers to its maple-like foliage. Confusingly, there's a totally distinct plant called "sycamore maple" (Acer pseudoplatanus) that gets its name from its resemblance to sycamore.
There are also planetree cultivars:
- Platanus × acerifolia 'Bloodgood': more resistant to anthracnose disease than the species
- Platanus orientalis 'Digitata': has deeply-dissected palmate leaves
- Platanus occidentalis 'Howard': valued for color of its new leaves, which are bright yellow (although this color fades in summer)
For the most part, sycamore needs to be pruned only after limbs have been damaged. The damaged limbs should be pruned back to the collar. Dead or diseased branches should be pruned off whenever you spot them. The only need for corrective pruning you may encounter is in those rare instances when a branch grows in a radically upright direction, forming a tight crotch with the trunk. Such an angle results in instability. This type of pruning is best left to professionals. Happily, American sycamore generally produces nicely horizontal limbs.
Propagating Sycamore Trees
Sycamore can be propagated by seed or by taking (softwood) cuttings, but, if your plant is a cultivar, your only means of propagating is by cuttings taken in early summer. Here’s how to propagate a sycamore cultivar via cuttings:
- Use a sharp knife to make your cut. Select a new-growth branch (it should have a pair of buds on the bottom and two pairs of leaves). Cut a shoot 6 to 8 inches long.
- Get a planting container ready by filling it with potting soil. Using a pencil, poke a hole into this soil. Take off any leaves growing out of the bottom of the branch (but keep the buds). Dip the bottom of the cutting in a rooting hormone. Insert it into the hole. Water the potting soil. Place the cutting in a warm, sheltered spot in indirect light.
- Keep the potting soil moist until the cutting roots. The best way to do this is with a plastic "tent." Stick a small stake into the planting container and hang a clear plastic bag over it. Lift up the plastic to mist the potting soil regularly.
- Once the cutting has put out roots about 1 inch long, take off the plastic tent. Continue to maintain an evenly moist soil. Transplant the rooted cutting to your yard next spring after frost danger has passed.
How to Grow Sycamore Tree From Seed
If your sycamore isn't a cultivar, you can grow it from seed, which comes from the pods.
Wait till the pods drop in spring so that nature takes care of any required stratification. Break a pod open to remove its seed. Take off the fuzz attached to the seed. Pre-soak for 24 hours. Fill a planting container with seed-starting medium and moisten it. Sow seed and cover with ¼ inch of seed-starting medium. Keep the medium moist. Seed will germinate in 15 days. Plant outdoors after danger of frost has passed.
American sycamore is a very hardy tree. No extra care is required to overwinter it. Besides that, it's actually quite stunning in winter. The bark in the upper canopy is white and the branches are geometric, both of which are usually obstructed before leaf drop.
Common Pests and Plant Diseases
Besides its messiness, sycamore causes headaches in other ways. It's prone to attacks from insects and diseases. American sycamore is one of many plants susceptible to aphid infestations. Aphids can invade any landscape, but they run especially rampant on landscapes where the use of chemicals has eliminated aphid predators. If you get aphids, spray with the organic insecticide, Neem oil.
American sycamore is susceptible to anthracnose. If you live in a hot, humid region, such as the Southeast, your plants are naturally more prone to such fungal diseases. The solution is to grow the cultivar, Platanus × acerifolia 'Bloodgood', which is resistant to anthracnose.
Are there any benefits in growing sycamore?
Yes. Its fast growth rate can make it a better choice for a shade tree if your primary objective is to have shade in the yard as quickly as possible.
Besides messiness, do sycamore trees have any other objectionable qualities?
Yes. Mature sycamores may develop masses of exposed roots. These roots are difficult to mow around on a lawn. And if you strike one with your blade, it can damage your blade. The solution is to avoid growing sycamore as a lawn tree. It's better situated in woodland gardens.
Does sycamore tree have nice fall foliage?
No. It turns an uninspiring yellow color in fall.