June 2013 - Weed of the Month Information about River Lily. Published

weed of the month
For more information email: [email protected]
or visit: www.ecan.govt.nz/weeds
June
2013
River lily (old name: Kaffir lily)
Hesperantha coccinea (old name: Schizostylis coccinea)
Why is it a problem?
Identification
• Attractive iris with upright flower stalks up to
90 cm high.
•Up to 15 alternating flowers per stem in
autumn.
• Flowers with six petals and colours ranging
from red to pink to white.
• Slender sword-like leaves up to 30 cm long.
Where is it found?
River lily likes damp ground in gardens and
paddocks, on roadsides, and along drains, water
races and streams.
Hesperantha coccinea flower and leaves.
Photo: M. von Tippelskirch (ECan)
River lily propagates from rhizomes and small
corms (bulbs) growing on stems. Likely methods
of spread are via seeds and dislodged rhizomes
and corms in waterways (beware of spreading
them with drain cleaning machinery). River lily
tends to invade stream, water race and drain
margins and can form almost continuous clumps
that exclude native stream margin plants.
Similar species
When not in flower, river lily resembles many other
iris species with its sword-like leaves.
Hesperantha coccinea red and pink
varieties and infestation.
Hesperantha coccinea leaf closeup.
Photo: M. von Tippelskirch (ECan)
Photo: M. von Tippelskirch (ECan)
Control
While there is no specific information in the
literature on control methods for river lily, the
following recommendations could be tried as they
are successful on similar species:
Montbretia:
Yellow flag:
2. Spray with glyphosate (10 ml/L) + metsulfuronmethyl 600 g/kg (4 g/10L) + penetrant.
http://www.weedbusters.org.nz/weed_info/detail.asp?WeedID=13
http://www.weedbusters.org.nz/weed_info/detail.asp?WeedID=38
1. Weed wipe with 1 g metsulfuron-methyl 600 g/kg
+ 100 ml glyphosate + 20 ml penetrant/L.
1. Spray (spring–autumn) with metsulfuron-methyl
600 g/kg (5 g/10L).
Work from upstream to downstream to avoid
reinvasion.
2. Spray (spring–autumn) with glyphosate
(100 ml/L + penetrant).
REMEMBER – use all herbicides in accordance
with the manufacturer’s instructions and ensure no
herbicide comes into contact with
other plants, the soil or waterways.
3. Weed wipe (spring–autumn) with glyphosate
(333 ml/L + penetrant).
4. Stem injection (all year round) of 5 ml undiluted
glyphosate into each stem at the base.
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