Japanese Honeysuckle
Caprifoliaceae - Lonicera japonica
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What does it look like?

Vigorous evergreen (semi-evergreen in cold districts) climber with long, tough, wiry stems that twine clockwise, are purplish and hairy when young, and turn woody as they mature. Leaves (3-12 x 2-6 cm) are in opposite pairs on the stems, are shiny dark green (occasionally yellowish) on the top and lighter green underneath, and are wavy-edged to lobed when produced in cold climates, otherwise they are entire.

Pairs of 2-lipped, sweetly scented tubular white flowers (2-5 cm long) that age to yellow are produced from September to May, and are followed by egg-shaped, glossy black berries (5-7 mm diameter) in colder parts of NZ, each containing seeds (2mm).

Why is it a problem?

Climbing, smothering habit. Forms dense, long-lived masses. Tolerates moderate-shade, frost, salt, damage, wet or dry, most soils, high to low temperature. Very long stems layer profusely, moderate-fast growth rate. Poor seeder.

Climbs over and smothers most plants from ground to medium canopy. Can cause canopy collapse and subsequent invasion of grasses or ground vines. Provides support for faster growing weedy vines (e.g. blue morning glory, moth plant).

Control Methods

Options for control include:

  • Cut and stump-treat larger stems (within 10 minutes of cutting) with 5g metsulfuron–methyl (600g/kg e.g. Escort®) per 1 litre water; or
  • Spray summer-autumn with 125mls clopralid (300g/l e.g. Versatill®) + 20mls penetrant per 10 litres water or 5g metsulfuron-methyl + 10mls penetrant per 10 litres water.

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