Bushland Weeds Manual - Environmental Weeds Action Network

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Chapter 5 Broadleaf Herbs, Sedges and Succulents
Case Studies
Case study 5.2 Preventing further spread of a recent invader – Holly-leafed Senecio
(Senecio glastifolius)
Holly-leafed Senecio, a tall perennial
herb from the daisy family, occurs
naturally in the Cape Region of
South Africa. It was first recorded
as naturalised in Western Australia
in 1986 (Western Australian
Herbarium 1998). Collected from
the Mt Adelaide and Mt Clarence
Nature Reserves in the south west
town of Albany, Holly-leafed Senecio
was apparently an escapee from a
garden adjoining the reserve. A
series of fires facilitated rapid
expansion of the original infestation
and slashing of fire breaks
contributed to further spread of
seed. Holly-leafed Senecio now
occurs throughout much of the 260
hectares of Jarrah (Eucalyptus
marginata), Albany Blackbutt
(Eucalyptus staeri), and Marri
(Eucalyptus calophylla) woodlands,
as well as Allocasuarina open
woodland, in the reserves. In recent
years infestations have also been
found growing on coastal sands and
loams up to 20 kilometres from the
original infestation (Western
Australian Herbarium 1998). Hollyleafed
Senecio has the potential to
become a major weed of natural
areas around much of the south
coast of Western Australia
(Keighery 1999c).
Senecio glastifolius (photograph Greg Keighery)
Why is it such a successful
weed?
• Produces prolific amounts of
viable, wind dispersed seed.
• Some evidence of persistent
soil seedbank.
• Fire is a major mechanism for
establishment and facilitates
spread.
• Soil disturbance also facilitates
spread and establishment.
(from Williams et al. 1999)
Management
The Mt Adelaide and Mt Clarence
Nature Reserves are vested in the
City of Albany. Until very recently
few resources have been available
for weed management in the
Reserves. Although the original
infestation of Holly-leafed Senecio
threatened natural areas from
Augusta to Albany and possibly
beyond, it was never clear who was
responsible for its eradication.
Community volunteers initiated the
first control programs.
The following report comes
from Karin Baker, Friends of
Mt Adelaide and Mt Clarence
Nature Reserves
• 1998: Fire followed by good
rains led to prolific germination
of Holly-leafed Senecio on the
north face of the saddle
between Mt Adelaide and Mt
Clarence. Many people who
used the reserves for their
daily walks started hand-pulling
the plants and leaving them in
the Reserves. (It was not known
at this stage that they could
form seeds after being pulled).
Three community volunteers
started a hand-removal
program in a Casuarina open
woodland area, where the
thickest infestations occurred.
• 1999: Holly-leafed Senecio was
hand-removed from dense
thickets of Acacia pulchella up
to 700 mm high. Hand-pulling in
this area required thick gloves
and trousers. Some of the Hollyleafed
Senecio removed was
two and a half metres tall. This
time the plants were removed
from the site. We were learning!
• John Moore and Dale Baker, a
board member of the first CRC
(Cooperative Research Centre)
for Weed Management Systems
ran a series of herbicide trials.
Lontrel at 500 mL/ha applied
from a backpack mister in
spring was found to be effective
on the Holly-leafed Senecio and
caused little damage to the
native species in the area.
• The CRC for Weeds and the
Department of Agriculture,
Western Australia held the
state launch of ‘Weedbuster
Week’ at the Mt Adelaide and
Mt Clarence Reserves in
October. Over 100 people
turned up to hand-pull Hollyleafed
Senecio and the ‘Friends
of Mt Adelaide & Mt Clarence
Reserves’ was formed. The
following year the Bushcarers
Group, an umbrella group for
all the Friends groups that were
starting up around the city was
formed.
• Following on from the work
day, populations were sprayed
with Lontrel (500 mL/ha).