American Sycamore (Platanus occidentalis)

How much light does an American Sycamore need?

Outdoors, you can grow this tree in full sun, part shade or full shade. Of these, full sun is its preferred light level. Full sun is defined as six or more hours of direct sunlight a day. It also tolerates part shade and full shade.

• Light: Full sun, part shade and full shade (full sun preferred)^1,2

How often to water an American Sycamore

Water this tree enough to keep the soil medium to wet. It also tolerates soil that drains well, stays moist, or is occasionally wet. That range runs from well-drained ground up to spots that stay occasionally wet. That means medium-wet soil at the low end of its range and fully wet soil at the high end.

• Water: Medium to wet²

Best soil for an American Sycamore

This tree's soil can be well drained, moist or occasionally wet. A spot with any of those three conditions suits it, from ground that drains quickly to ground that holds water at times. Its soil pH can run from 5 to 8, from acidic to alkaline. That is a broad pH span, running from a fairly acidic mix at 5 up to a fairly alkaline one at 8.

• Soil drainage: Well drained, moist and occasionally wet^2,3
• Soil pH: pH 5–8⁴

Hardiness and temperature

Hardiness for this tree outdoors runs from USDA zone 4a up to zone 9b. That span starts at the colder zone 4a and runs to the warmer zone 9b. Within that full list, it is rated for zones 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a and 9b.

• Hardiness: Zones 4a–9b²

Pruning an American Sycamore

Prune this tree only from December through February. Limit pruning to light shaping and removing dead growth. Penn State Extension recommends pruning sycamores only during December and January, when the weather is dry. Avoid pruning it at other times of year.

• Pruning: Light shaping and Remove dead growth only (Jan–Feb, Dec)⁵

How to plant an American Sycamore

You can plant this tree outdoors in USDA hardiness zones 4a through 9b. At maturity, it typically reaches 75 to 100 ft (22.86-30.48 m) tall. Its spread at maturity also runs 75 to 100 ft (22.86-30.48 m), so give it plenty of room when you choose a planting site. It is native within the lower 48 states.

• Hardiness: Zones 4a–9b²

Winter care

This tree's USDA hardiness spans zone 4a through zone 9b outdoors. It is a deciduous tree. Prune it only during December through February. That pruning should be limited to light shaping or removing dead growth. Penn State Extension advises pruning only when the weather is dry.

• Hardiness: Zones 4a–9b²

How to propagate an American Sycamore

You can propagate this tree from seed. Cultivars are propagated by stem cuttings instead, taken as either hardwood or softwood cuttings. That gives you two propagation routes: growing from seed, or taking a cutting from an existing plant. Which one you use depends on whether you are growing the species itself or a named cultivar of it.

• Propagation: Seed and stem cuttings³

Common problems

This tree can face several insect pests. These include sycamore lace bugs, sycamore leaf beetles, Japanese beetles, caterpillars, spider mites, aphids, scales and borers. Its disease problems include anthracnose, canker, leaf spot, powdery mildew and bacterial leaf scorch. Both lists cover insects and diseases reported for this species.

• Common pests: sycamore lace bug, sycamore leaf beetle, japanese beetle, caterpillars, spider mites, aphids, scales and borers^2,6
• Common diseases: anthracnose, canker, leaf spot, powdery mildew and bacterial leaf scorch^6,2

Questions and answers

Is American sycamore toxic to cats or dogs?

This tree is not toxic to cats or dogs, according to the ASPCA and NC State Extension. Neither source records any toxic parts or symptoms for it.

What light does American sycamore need outdoors?

This tree takes full sun, part shade or full shade outdoors, with full sun as its preferred light level. Full sun means six or more hours of direct sunlight a day.

How do you propagate American sycamore?

You can grow this tree from seed. Cultivars are propagated instead from stem cuttings, either hardwood or softwood. This gives growers two ways to start new plants, from seed or from a cutting.