How to Grow and Care for a Sycamore Tree

The American sycamore tree is a deciduous tree that grows 75 to 100 feet tall—the largest deciduous tree in North America. In addition to height, one characteristic that's special about a sycamore tree is its bark. Outer sycamore tree bark is brown and peels away from the trunk to reveal a lighter inner bark. Sycamore tree leaves are large (4 to 10 inches across) and divided into three to five lobes with coarsely toothed edges. Sycamore tree identification also occurs via the tree's seed pods. The pods—i.e., the sycamore tree fruit—are sometimes referred to as sycamore tree balls because they have a fuzzy, spherical shape (roughly 1.5 inch in diameter).

Sycamore trees grow best in deep, moist, rich soils. The best time to plant one is late winter or early spring. They have a fast growth rate and good tolerance for pollution, wind, wet soil, and even drought. The sycamore tree is a good tree for shade. However, their large size can make sycamore trees a problem, as their widespread, shallow roots can damage pavement, underground pipes, and more.

Sycamore Tree Care

Because it grows along streams in the wild, the sycamore tree tolerates wet areas better than many trees do. It also tolerates the air pollution often found in urban settings. But you have to make sure you have a lot of space to accommodate this tree's mature size when you plant one.

Plan to water your American sycamore tree during periods of prolonged drought and feed it in the spring. Pruning usually isn't an extensive task. But you do have to watch out for pests and diseases. 

Light

Grow sycamore trees in full sun for best results, though they do tolerate some shade.

Soil

Sycamore trees can tolerate a range of soil types and soil pH levels. An average garden loam with good drainage should be sufficient.

Water

For best results, keep the soil evenly moist. An established American sycamore tree has some drought tolerance.

Temperature and Humidity

Adaptable to a wide range of climates (zones 4 to 9), the sycamore tree isn't troubled by humidity and performs equally well in cooler and warmer zones.

Fertilizer

The 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 the 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 the American sycamore tree.

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 (though this color fades in summer)

Pruning

For the most part, the sycamore tree 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 whenever you spot them.

The only need for corrective pruning you might 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 trees generally produce nicely horizontal limbs.

Propagating Sycamore Trees

Sycamore trees 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:

1. 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.
2. 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.
3. 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.
4. 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 Trees From Seed

If your sycamore isn't a cultivar, you can grow it from seed, which comes from the pods. Wait until 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.

Overwintering

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 & Plant Diseases

The American sycamore tree 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 also 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.