What does it look like?
Sycamore is a large deciduous tree up to 20m tall, with a smooth trunk. Leaves are five-lobed, up to 20cm long, green but with reddish petioles up to 15cm long. Dense clusters of small, green flowers occur during October-November, with fruit in late summer-early autumn. Seeds are 0.5-1cm long with wings up to 4cm long.
Preferred habitats include open, regenerating forest or scrub and forest margins (including pine plantations as well as native vegetation). It also prefers short-stature plant communities, road and rail corridors. It colonises predominantly in open sites, but growth is slower in shade. Highly fertile and high pH soils are preferred. It tolerates a range of soil moisture, from damp gullies to moderate drought and is fairly frost tolerant.
Why is it a problem?
Sycamore seedlings grow rapidly, and it’s a competitive coloniser of open sites. A persistent seedling bank can form under shade. There is potential for the seedling bank to rapidly exploit future canopy openings but growth rates remain very slow under intact canopy. It’s less competitive on low fertility soils, with a possible allelopathic effect that suppresses other plants.
It produces seeds prolifically, with each tree capable of generating over 10,000 seeds annually. Germination occurs in spring as dormancy is broken by winter. The seed bank is unlikely to persist beyond a single season.
It's primarily dispersed locally by wind and gravity, typically within 50–100 metres. Some downstream dispersal also occurs via water movement.
Control methods
Physical control
Dig out small plants (all year round) and dispose of at refuse transfer station, dry and burn or compost.
Herbicide Control
Drill and fill/stem injections: Make 1 hole every 200 mm around the trunk and fill with undiluted glyphosate. Or,
Cut trunk near to the ground and paint stump (summer-autumn) with 5g metsulfuron-methyl (600g/kg) per 1L water; or 50ml Tordon Brushkiller per 1L water; or picloram gel. Or,
Over spray (full leaf stage only) with 5g metsulfuron-methyl (600g/kg) per 10L water.
CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.
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