Orange cestrum
Botanical name
Cestrum aurantiacum
Family
Solanaceae (nightshade)
Where is it originally from?
Temperate and tropics of Americas
What does it look like?
Smelly shrub (<2 m) with erect, hairless stems that become woody. Leaves (4-15 x 2-7 cm) are hairless and smell strongly when bruised. Orange, scentless, tubular flowers (20-25 mm) with petal margins bent backwards appear Nov-July and are followed by clusters of white berries (15 x 20 mm).
Are there any similar species?
C. elegans, C. fasciculatum, C. nocturnum, C. parqui. Many native shrub species, eg. mahoe.
Why is it weedy?
Moderate to high shade tolerance. Grows in fertile soils, damp, hot or cold. Forms dense, shady masses, and produces many long-lived and widely-dispersed seeds. Poisonous, not grazed.
How does it spread?
Birds, also in water during flooding, soil movement, and dumping of greenwaste.
What damage does it do?
Forms dense stands in forest understory, preventing native species from establishing. Poisonous berries and rotting vegetation may affect native fauna.
Which habitats is it likely to invade?
Disturbed and open forest and margins, streamsides, and shrublands, potentially throughout NZ.
What can I do to get rid of it?
1. Physical removal - Hand pull small plants, or dig out entire plant including roots (all year round).
2. Cut and paste - Apply picloram gel (43g/l strength) to the entire cut stem. Do not use near desirable plants or overwater or wetlands. When a gel is inadequate apply a formulation containing triclopyr and picloram 50ml/L water mix. Apply the mixture over the entire exposed surface of the cut stump, i.e. top and sides.
3. Foliar spray - Apply Triclopyr herbicide (600g/L active ingredient) at 6ml/L plus organosilicone penetrant (1ml/L) to thoroughly wet all parts of plant.
CAUTION: When using any herbicide or pesticide, PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and directions for the purchase, use and storage of the product, are followed and adhered to.
What can I do to stop it coming back?
Hard to distinguish from many native species (apart from foetid smell), best controlled when in flower. Wear gloves when handling, exclude stock at all times. Replant bared sites to minimise regrowth. Check for seedlings 6-monthly.
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