Download Environmental Weeds of the Eastern Hills Region

Environmental Weeds
of the
Eastern Hills Region
(DRAFT)
50 weeds you should know about
Compiled for our community
by
Wooroloo Brook LCDC
Environmental Weeds
of the
Eastern Hills Region
(DRAFT)
©2002 Wooroloo Brook Land Conservation District Committee.
Copyright: No part of this publication can be copied without permission of the
Wooroloo Brook LCDC. Contact: [email protected]
Acknowledgements:
Thanks go to Zamun Mohammed from the Green Reserve program for his help in
compiling the data.
Disclaimer: These notes are in draft and therefore are incomplete and are
compiled as a guide, from a variety of sources and are not necessarily the views
of the Wooroloo Brook Land Conservation District Committee.
Main references:
Bush Invaders of South-East Australia
Adam Muyt
©2001 published by RG and FJ Richardson
Southern Weeds and their Control
John Moore & Judy Wheeler
©2002 published by the Department of Agriculture WA
Other Useful References
Western Weeds
BMJ Hussey, GJ Keigher5y, RD Cousens, J Dodd, SG Lloyd
Has descriptions and photos of nearly all naturalized plants.
Available from Agriculture WA and Department of Conservation and Land Management Como.
Bushland Weeds – A guide to their management
Kate Brown, Kris Brooks
Has case studies and good control information.
Available from the Environmental Weeds Action Network
Or check out the following websites:
www.nra.gov.au
www.agric.wa.gov.au
http://www.calm.wa.gov.au/science/florabase.html
3
INDEX
African Lovegrass
Arum Lily
Bamboo
Barley Grass
Blackberry (Bramble)
Blue Periwinkle
Blow Fly Grass (Quaking
Grass)
Bridal Creeper
Brome Grass
Broom
Bull Rush
Caltrop
Cape Broom
Cape Tulip
Cape Weed
Clover
Dock
Doublegee
Evening Primrose
Flatweed (Dandelion)
Freesia, Babinia, Ixia
Fleabane
Gladiolus
Guildford Grass
Lathyrus
5
5
6
6
6
7
7
Lavender
Lupin
Melons
Morning Glory
Nasturtium
Nightshade (Blackberry)
Pampas Grass
16
16
16
17
17
18
18
8
8
9
9
10
10
11
11
11
12
12
13
13
13
14
14
15
15
Patterson’s Curse
Poplar
Radiata Pine
Ryegrass
Silver Grass
Storksbill
Soursob
Stinkwort
Storksbill
Tagastaste (Tree Lucerne)
Veldt Grass
Victorian Tee Tree
Watsonia
Wattles
Wild Oats
Wild Radish
Willow
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19
20
20
21
21
21
22
22
23
23
24
24
25
25
25
26
4
5
Environmental Weed
African Lovegrass
FACTS
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Can seed 5-6 times per year
Road verges & disturbed ground
Difficult to control
Serious fire hazard
Prolific seeder
Found on disturbed sites such as road & rail reserves and sometimes invading bushland
Native to South Africa
Control
•
•
•
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Smaller plants can be dug out. To prevent regrowth ensure the crown is removed.
Larger infestations can be burnt or slashed.
Plants can be sprayed with non-selective or grass-selective herbicides
Cultivation and rotational grazing usually provides reasonable control
Control for 2-3 years
Environmental Weed
Arum Lily
FACTS
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Declared weed
Usually found in moist areas such as water courses and open rural land
Forms dense stands which crowd out pasture species & native plants
Yellow spike & white flower is poisonous
Toxic to stock & reported to cause death to children
Sap causes eczema
Impedes water flow
Spread by underground storage tubers and berries are spread by birds
Popular garden plant
Often discarded irresponsibly
Still sold in nurseries
From South Africa
Flowers mostly late winter and spring
Control
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Removal of plants including tubers and roots by hand or digging.
Multiple rotary hoeing over a few years provides control
Cut flowers to prevent birds spreading seed
Encourage control on a district basis to reduce re-infestation.
Herbicides provide the most effective control
In sensitive areas a blanket wiper may be used
6
Environmental Weed
Bamboo
FACTS
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Introduced as an ornamental plant & now is a garden escapee
Dispersed vegetatively & by water
Smothers watercourses
Reproduces by dividing clumps, rhizomes (underground stems) or by cuttings from
stems.
Removal is often difficult because of accessibility
From southern Europe, Mediterranean area & Asia
•
•
Control
Environmental Weed
Barley Grass
Barley Grass and Sea Barley Grass
FACTS
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Native to Europe
Weed of crops, roadsides, disturbed and saline areas
Flowers in spring
Control
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Prevent seed set for 1-2 years
Hand weeding
Mowing
Cultivation
Herbicides
Environmental Weed
Blackberry (Bramble)
FACTS
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Declared serious weed
Forms dense prickly scrambling thickets usually along creek lines & wetlands
Birds & other animals spread it by eating the fruit & voiding the seeds
Difficult to eradicate
Spread by seeds (birds & animals) & roots, stems and where arching canes contact the
soil. Also reproduces from cuttings, root parts and offshoots.
Smothers native flora
7
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Poor stabilisation of watercourse banks
Harbour for rabbits and other vermin
Fire hazard
From Europe
Flowers in spring and summer
Control
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For small infestation seedlings and small plants can be dug out when soils are moist.
For larger infestations plants can be treated with selective and non-selective herbicides.
Most of the root system must be removed for effective control.
Burning is not effective apart from allowing better access
Three annual summer applications of herbicide when blackberry is actively growing.
Grazing with goats is reasonably effective
Replant native species after control
Biocontrol rust fungi have established but have had little impact
Environmental Weed
Blue Periwinkle
FACTS
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Sprawling groundcover
Blue to violet flowers with a white throat
Garden escape
Sometimes found in dark shady areas
Able to cover large areas by producing roots where the stems are in contact with the
ground.
Naïve to the Mediterranean
Widely cultivated in Australia
Flowers from winter to early summer
Control
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Rake to lift vines off the ground then mow or cut the vines
Regrowth can be sprayed with non-selective or grass-selective herbicides. Several
applications about three months apart are required.
Spot spray or manually remove the last remnants of plants as these will be the source of
reinfestation.
Hot fires and solarisation provide some control.
Environmental Weed
Blow Fly Grass
Quaking Grass
FACTS
•
•
Widespread in granite outcrops, wastelands, wetlands & woodlands.
Seeds germinate in autumn in response to rains and plants grow over late autumn-winter,
then flower, set seed and die off in late spring or early summer.
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Large populations can rapidly build up as most seed is viable and germinates the
following year.
Large populations can reduce ground-flora species rich-ness in grassy woodlands by
over half.
Summer die-off plants can increase the fire hazard in many grassy ecosystems.
Native of the Mediterranean
Control
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Plants are easy hand-pull as roots are very shallow. Material without seed can be left to dry
out on-site.
Prevent seed set for 3-5 years
Scorching with gas burner before flowering is effective
Unripe seed heads can be gathered using catcher mowers. Avoid mowing stands with
ripened heads as they shatter and disperse very easily. Infestations can also be mown at the
time the first anthers emerge in spring. Cut close to ground level to prevent flowering.
Burn semi-ripe or ripe seed heads in late spring-early summer using hand-held gas burners.
Plants can be sprayed with non-selective or grass-selective herbicides.
Environmental Weed
Bridal Creeper
FACTS
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Extremely invasive
Urgent environmental weed problem
Forms dense cover smothering everything
Commonly found on roadside verges & creek lines
Is sold in nurseries for hanging baskets.
Produces roots & stems & therefore takes root whenever it comes into contact with the soil.
Can regenerate repeatedly from underground reserves after slashing, burning and spraying
Seeds spread by birds
From South Africa as ornamental plant.
Control
•
Seedlings and small infestations can be dug out. Mats of plant roots should be rolled up and
destroyed. Always monitoring is necessary for re growth over the next year.
• Plants can be sprayed with non-selective and selective herbicide.
• Biological control: (ie leaf hopper, rust fungus contact CSIRO)
Environmental Weed
Brome Grasses
FACTS
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Eleven species in WA
Inhabits native bushland, road reserves and cereal crops
Widespread in disturbed areas
Native of the Mediterranean, South America & Europe
9
Control
Prevent seed set for 1-2 years
Mowing and cultivation
Environmental Weed
Broom
English & Flaxleaf
FACTS
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Dense evergreen shrub. Produces numerous suckers from a taproot.
Seeds are long lived in the soil and come up after fire before native shrubs can regenerate
Grows rapidly & produces fire resistant seeds. Heavy seeder with seed being spread by
birds, vehicles or stock.
Forms dense permanent thickets. Harbours rodents. Highly in flammable.
Inhabits native bushland & road reserves
Control
• Seedlings and smaller plants can be hand pulled or dug out. Tops have tendency to break
away when pulled so if roots remain they should be dug out.
• Plants can be treated using the Cut-Paint method.
Plants can be slashed or burnt to stimulate seed germination for follow up control.
• Plants can sprayed with non-selective herbicides.
Environmental Weed
Bull Rush
Broad -leaved Combungi
FACTS
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Aquatic plant
Serious threat to wetlands, rivers & damplands
Competes with the WA native Narrow-leaved Cumbungi & other natives
Spread by animals, water & wind
Chokes waterways
Needs to be accurately identified before removal. The WA native is narrower and has a
paler cinnamon brown flower spike with a narrower female part. Hybrids also exist.
Native to the Eastern States
•
Control
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Eradication is difficult because of large seed production and hard to kill root system.
Cultivation, mowing, burning and herbicides are used for control.
In areas with reliable frosts, autumn cultivations to expose rhizomes can be useful.
Cutting the stems 150 mm below the water level at flowering, in late spring, results in
rhizome decay.
Burning helps reduce the build up of dead plant material that clogs channels and reduces
subsequent growth.
In dams, lower the water level, bulldoze or burn then flood deeply.
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When removing by hand ensure the rhizomatous root is removed.
Use herbicide products registered for aquatic situations to reduce affects on aquatic
organisms.
Environmental Weed
Caltrop
FACTS
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Declared weed
Invasive to pasturelands, wastelands & road reserves
Has a sharp spined burr which contains seeds
The burr can be transported by car tyres, shoes and the fur of animals.
Seeds can germinate after summer rain events & growth is vigorous during this time
Control is prolonged and difficult
Control
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Small infestations by hand pulling.
Larger infestations with a combination of mechanical and herbicide control.
Environmental Weed
Cape Broom
FACTS
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Dense evergreen shrub
Produces numerous taproots from suckers
Seeds are long-lived in the soil and come up after fire before native shrubs can
regenerate
Grows rapidly & produces fire resistant seeds
Forms dense permanent thickets
Harbours rodents
Highly in flammable
From South Africa
Control
11
Environmental Weed
Cape Tulip
One-leaved and Two-leaved
FACTS
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Declared weed
Spread by seeds & corms
Found in pastures, woodlands & disturbed lands
Toxic to stock
Takes many years to prevent reoccurrence
Native to South Africa
Control
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Plants can be dug out when soils are moist. Removal should be undertaken before
flowering.
Plants can be treated with selective or non-selective herbicide at flowering. Control
normally takes several years and follow up is essential.
Cultivation to expose the corms a few weeks after spraying may improve control.
Environmental Weed
Cape Weed
FACTS
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Annual daisy
Common weed of pastures, crops , roadsides and disturbed bushland.
Native to South Africa
Control
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Plants can be dug out before flowering is effective.
Mowing is only effective if repeated regularly and close to the ground.
Cultivation can be variable as Capeweed transplants readily in wet conditions.
Grazing is ineffective.
Plants can be treated with selective or non-selective herbicide at flowering.
Environmental Weed
Clover
Narrowleaf, Hare’s Foot, Hop, Suckling, Cluster, Ball, Rose, White, Subterranean, Woolly
FACTS
Mostly introduced as pasture plants
12
Control
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Hand pull odd plants in winter before flowering
Repeat annual herbicide spraying for several years.
Prevent seed set for 5 years
Exclude stock to prevent dispersal of seed and burrs
Clovers are relatively tolerant to grazing and mowing.
Environmental Weed
Dock
FACTS
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Some seeds remain viable for 20 years.
Invades paddocks
Likes damper soils, creeks & disturbed wetlands
Prolific seeder having counted 40 000 seeds on one plant of curled dock
Seeds may germinate at any time during the growing season
Competes with crops, pastures and lawns for light moisture & nutrients.
Some animals have suffered stomach ailments and dermatitis after grazing docks heavily
Five species
Mature dock has deep root stock
Perennial herbs with erect flowering stems up to 1.25 m tall and large leaves at the base.
Native of Europe, Africa & Asia.
Control
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Seedlings and small infestations can be dug out. Seed head should be removed. Continual
cutting eventually kill dock. Where plants can not be treated immediately, removing fruit
before it ripens in summer-autumn can prevent spread.
Plants can be sprayed with non-selective or selective herbicides. Broadleaf selective
herbicides are better and application at late spring-early summer i.e. before fruit forms is the
best. Treatment usually has to be repeated over 2-4 years.
Dock Moth
Grazing by goats although grazing and mowing can lead to greater stands.
Environmental Weed
Doublegee
FACTS
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Declared pest plant
Agricultural & wasteland weed
Three rigid spines well adapted to sticking to anything
Introduced from South Africa as a salad vegetable & unintentionally in hay
Flowers in spring
Produces seed very quickly.
13
Control
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Remove small populations by hand and destroy plants with seeds. Older plants tend to break
off and regrow.
Spray in winter and spring with herbicide.
Environmental Weed
Evening Primrose
FACTS
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Common invader of roadside verges
Likes disturbed sites
Night flowering
Moth pollinated
From South America
Control
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Seedlings and small plants can be hand-pulled or dug out. All roots and any layering stems
must be removed as the plant will regrow from these. Use a weed fork and ensure all fleshy
rootstock is collected and burnt or buried more than one metre deep.
Plants can be treated using the cut-paint method before flowering commences.
Plants can be sprayed with non-selective and selective herbicides.
Environmental Weed
Flatweed (Dandelion)
FACTS
Flower much of the year
Control
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Remove small populations by hand using a weed fork to extract the taproot.
Cultivation provides good control but leaves the area susceptible to reinvasion.
Mowing and grazing are ineffective.
Environmental Weed
Freesia, Babiana, Ixia
FACTS
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Popular garden bulbs. Freesia is a horticultural hybrid, originally from South Africa
Seriously invading bushland, granite outcrops and woodlands
Still sold in nurseries
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Difficult to eradicate
Leaves 8-30 cm long, 5-10 mm wide, linear, flat, tapering gradually, mid-veins prominent,
green both sides, arranged as a fan.
Flowers 2-4 cm long, 6 petals, white to cream with yellow markings, trumpet -shaped,
strongly scented, flowers Sept-Oct.
Control
• Plants can be dug out. Remove when soils are moist otherwise corms may dislodge. When
digging, carefully excavate around the plant ensuring all corms are moved.
• Grazing and mowing provide control but don’t do this after seed or cormal formation as this
may increase spread.
• If plants have already developed seeds and leaf bulbils then carefully cut and bag these
before digging out of the corms.
• Plants can be treated with non-selective and selective herbicides. Treat before new corms
develop and flower stems lengthen in late winter-early spring.
• Start control at the top of the Catchment.
Environmental Weed
Fleabane
FACTS
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Flowers in summer and autumn
Common to roadsides and disturbed bushland
Control
• Hand pulling is effective on loose soils but on heavier soils a weed fork is required to prevent
the plant breaking and regrowing from the base.
• Mowing is not effective.
• Grazing usually gives adequate control.
• Plants can be treated with non-selective and selective herbicides.
Environmental Weed
Gladiolus
Pink
FACTS
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Looks similar to Watsonia
Introduced to gardens
Pink flowers in spring
Found on road verges, bushland and wasteland
Usually scattered
From Africa & the Mediterranean
Control
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Plants can be dug out. Remove when soils are moist otherwise corms may dislodge. When
digging, carefully excavate around the plant ensuring all corms are removed.
Plants can be treated with non-selective and selective herbicides.
Environmental Weed
Guildford Grass
Onion Grass
FACTS
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Produced from a corm
Roadside, garden and pasture weed also occurring in bushland
Native to South Africa
Flowers in late winter and spring
Pink, purple and yellow flowers
Control
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Manual control is difficult because the corms tend to break off unless the soil is very loose.
Very regular close mowing with a rotary mower and cultivation in summer and early autumn
to expose corms so they dry out and die provides some control but may also spread the
infestation.
Plants can be treated with non-selective and selective herbicides.
Environmental Weed
Lathyrus
FACTS
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Climbing herb with winged stem.
Stems 3-7 mm wide, light green or grey-green, angular, winged, hairless. Leaves
alternately divided into 3 florets, one leaflet modified to form a tendril.
Rampant perennial with purple, pink or white sweet pea like flowers.
Ripe seed may be ejected several metres away from parent plants.
Seeds can remain viable in the soil for several years.
Found on roadsides and woodlands
Creates a fire hazard when it dies back in summer
Native to Europe, western Mediterranean and the Azores.
Control
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Small infestations can be manually removed. All stems in contact with soil must be removed
and the roots dug out to ensure no regrowth occurs.
Larger vines can be treated using the stem-scrape or cut-paint method.
Plants can be sprayed with non-selective herbicides.
16
Environmental Weed
Lavender
FACTS
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Garden escapee
Found on roadsides, wastelands, creeks and drainage lines
Spanish lavender is more common than English and French
It is typically establishes on disturbed, bare or lightly vegetated sites, growing on shallow
rocky ground, sandy soils and heavier clays.
Most growth occurs over winter, spring and early summer.
Plants take two to three years to reach sexual maturity.
From the Mediterranean
Control
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Plants are easily hand-pulled or dug out, particularly in moist soils. To prevent regrowth roots
should be removed properly.
Dense infestations can be burnt in autumn. This will open up infestations for follow up
control.
Plants can be treated with non-selective and selective herbicides. Treatments are best
applied in spring, right at the peak flowering period.
Environmental Weed
Lupin
White, Narrowleaf, Blue, Yellow
FACT
Common weed to roadsides, wastelands and sometimes bushland.
Control
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Remove small populations by hand, mowing, grazing, cultivation before flowering and
destroy plants with seeds.
Easy to remove by hand
Spray in winter with herbicide.
Grazing by native animals usually keeps them under control in healthy bushland.
Environmental Weed
Melons
FACTS
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Wild relative of the water melon (Afghan)
Bitter & unpalatable
The small prickly paddy melon is poisonous
Grows in paddocks, roadsides and disturbed water courses
17
• Grows with smaller prickly paddy melon
• Native of southern Africa
Control
Pull out, wipe and spot spray with appropriate herbicide when actively growing.
Environmental Weed
Morning Glory
FACTS
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Garden escapee
Invasions often commence in disturbed bush land margins and openings and expand as
the canopy as the canopy dies and light level increase.
Rampant climber often used to cover fences.
Smothers all vegetation.
Regrown from pieces of roots, shoots and seeds
Seed is dispersed by wind, in garden refuse and during removal.
From Europe & Asia
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Control
•
Small infestations can be manually removed. All stems in contact with soil must be
removed and the roots dug out to ensure no regrowth occurs.
Vines can be severed at the base and left to dry out in the canopy.
Larger vines can be treated using the stem-scrape or cut-paint method.
Plants can be sprayed with non-selective herbicides. Sever any vines climbing through
indigenous vegetation at chest height, lay lower sections on the ground then apply a
herbicide spray over them.
•
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Environmental Weed
Nasturtium
FACTS
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Sold by nurseries
Garden escapee of hybrid origin
Large seeds which germinate on disturbed soils
It is frequently dumped irresponsibly
Occurs on wastelands & creek lines
From Peru and Ecuador
Flowers in spring
Control
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Manually remove, ensuring the larger roots are also collected and burnt.
There is often a large germination of seedlings following removal of parent plants.
Can be controlled by light cultivation or by herbicides.
18
Environmental Weed
Nightshade (Blackberry)
FACTS
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Common garden weed
Young fruit is toxic especially to stock & young children
Spread by birds
Found in wetlands, wastelands, waterways, disturbed woodlands, and crops
Usually hairy, and often prickly.
The flower is star shaped; some times a very pointed star and flowers much of the year.
The fruit is succulent berry.
There are 43 native species in Western Australia
Only germinates where soil has been bared.
Control
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Hand-pull small populations before flowering.
Spray seedlings with appropriate herbicide.
Encourage shrub species and litter build up to reduce infestation.
Environmental Weed
Pampas Grass
FACTS
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Pampas grasses are aggressive colonizers, particularly of disturbed, open sites.
Individual flower heads contain up to 100 000 seeds with viability exceeding 75%.
Wind may disperse seed for several kilometers.
Roots grow to a depth of 3m with a spread of up to 4 m.
Leaves long, narrow, strap-like with a roughened, adhesive surface.
Flowering stems –6 m high, upright or nodding, emerging spring summer. Inflorescence
feathery, plume-like.
Native to South America
Control
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Smaller plants can be dug out. To prevent regrowth ensure the rhizomes are removed.
Where plants cannot be treated immediately spread can be limited by removing emerging
flowering stems.
Backhoes and excavators can be used to lift out large plants which can then be dried out
and burnt or buried more than one metre deep.
Where there is no risk of damage to indigenous vegetation, stock can be utilized to
control spread.
Plants can be sprayed with non-selective herbicides.
Graze infested areas if possible or replant to native shrub species.
19
Environmental Weed
Patterson’s Curse (Salvation Jane)
FACTS
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Declared weed
Introduced as a possible fodder species & therefore known as Salvation Jane
700 000 hectares of it in WA
Have purple flowers but occasionally white or pink.
Prolific seeder – more than 5000 seeds per plant. A seed bank of up to 30 000 seeds per
square metre has been reported.
Seeds can remain dormant for up to five years.
Widespread on agricultural land & roadsides and is a threat to under storey species in
reserves
Produces liver-toxic alkaloids & high intake will kill grazing animals.
Competes with other pasture plants.
Reduces soil fertility
Pollen & bristles may cause allergic reactions to humans.
Spread only through movement of seeds. I.e. through hay, wind, certified seed, animals
Can grow to the exclusion of all else
Came from the Mediterranean in the 1850s
Flowers late winter and spring and can be white or purple
Control
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For small invasion plants can be dug out with tap root. Seed spread can be minimized by
cutting away mature, seed-laden stems. Burn if flowering or seeding
Selective and non-selective herbicide can be sprayed for extreme invasion. Application of
herbicide should at early flowering period, other wise some seeds may ripen as plants die
back.
Cultivation controls existing plants but tends to encourage new germination
Winter grazing tends to increase infestations
Crown borer, a biological control, produces damage.
Graze heavily with wethers over spring to reduce seed production.
Environmental Weed
Poplar
(White & Lombardy)
FACTS
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Reproduces from suckers & cuttings
•
Will continue to sucker until parent plant is killed
•
Planted as an ornamental
•
Forms dense stands
•
Occurs on road verges, paddocks and disturbed wetlands
•
Native to Europe
Control
20
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Suckers can be controlled by cutting off plant tops repeatedly.
Environmental Weed
Radiata Pine
FACTS
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Grown commercially for timber harvest
Prolific seeder into adjacent roadsides and bushland
Affects native vegetation due to its vigorous growth & acidifying affect
Little to offer most native fauna.
Winged seeds are spread by the wind
From coastal California USA
Control
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Seedlings and small plants are easily hand-pulled or dug out. To prevent regrowth ensure the
main root is removed.
Plants can be cut down. Stumps do not require treating with herbicide provided cuts are
made below any branches.
Plants can be treated using the Drill-Fill, Frilling or Ringbarking methods.
Infestations can be burnt. Seedlings and saplings can be destroyed with cool burns, but
larger plants usually require hot fires. Follow burns up with a control program targeting
seedlings and any remaining live trees.
Environmental Weed
Ryegrass
Annual
FACTS
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Introduced as a pasture species in the Wheatbelt
Infestations occur after crops are sown
Invades areas of disturbed and cultivated land and roadsides
Seed dispersal is airborne
Its pollen is a major contributor to discomfort of asthma sufferers
Seed heads can be infected with a toxicity making them toxic.
From the Mediterranean, Europe, North Africa & Asia
Control
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Environmental Weed
Silver Grass
FACTS
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Widespread weed of cereal crops, pastures, revegetation areas and of many other
vegetation types
Native to Europe
Flower late winter to early January
Control
Prevent seed set for 2-3 years by mowing, cultivation, hand weeding and herbicides.
Environmental Weed
Storksbill
FACTS
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Common to pasture, wasteland, roadside
Flowers winter and spring
Control
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Prevent seed set for 3-5 years.
Manual removal and cultivation are effective.
Spray in winter and spring with herbicide. Hormone herbicides provide good control of young
plants.
Environmental Weed
Soursob
Wood Sorrel, 4 O’clock, Oxalis spp
FACTS
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Declared plant
Invades pastures, crops, gardens and roadsides
From South Africa as a garden ornamental or in contaminated soil
Can be poisonous to stock in certain quantities
Competes with crops and annual pasture plants
Grows rapidly from food reserves in the bulb & quickly outgrows and shades most other
seedlings
Propagated by bulbs and tubers
Cut sections above the parent bulb are capable of forming new plants
Control
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Occasional plants can be carefully dug out but is difficult. Never hand-pull plants as bulbils
will inevitably dislodge.
Carefully excavate around the plant to ensure every bulbil is removed. Monitor for signs of
regrowth in following years.
Plants can be sprayed with non-selective herbicides. Repeat applications over 2-5 years are
commonly required.
Mowing and grazing are ineffective.
Environmental Weed
Stinkwort
FACTS
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Can cause stock losses and cause dermatitis
From the Mediterranean
Common to pasture, roadsides and wasteland
Control
• Plants can be manually removed. Plants in flower must be burnt as seed will develop from the
reserves of stems left on the ground.
• Heavy grazing (with old wethers) provides some control of young plants.
• Cultivation of larger plants is only effective if done before flowering.
• Mowing reduces seeding but only when cut close to the ground.
• Plants can be treated with non-selective and selective herbicides.
Environmental Weed
Storksbills
FACTS
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Pasture, wasteland and roadside weed.
Native to Europe and the Mediterranean
Flowers in winter and spring
The distinctive fruit is long and beaklike and splits into five fruitlets which, when mature,
separate and twist so that each seed is attached to a spirally-twisted corkscrew like awn.
Control
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Remove small populations by hand and destroy plants with seeds. Older plants tend to break
off and regrow.
Spray in winter and spring with herbicide.
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Environmental Weed
Tagasaste (Tree Lucerne)
FACTS
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Spread from farms to road reserves & occasionally enters native bushland displacing
other plants
Reproduced by seeds.
Seed is dispersed by birds, ants, slashing, machinery, in soil and garden refuse.
Used as supplementary stock fodder
Hardy & prolific seeder
Seeds may remain in soil for more than ten years
Seedlings rarely establish in dense shade
Readily forms large thickets & displaces native vegetation
Originally introduced as a hedge plant & fodder crop and has since become weedy on
road verges, sometimes invading bushland
From the Canary Islands
Flowers in winter and early spring
Control
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Small seedlings and smaller plants can be hand pulled or dug out.
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Plants can be treated using cut-paint method.
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Stands can be slashed or burnt to stimulate seed germination for follow up control.
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Bulldoze trees, burn. Then spray regrowth and seedlings.
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Grazing can provide control by ring barking the trees and consuming the seedlings.
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Plants can be sprayed with non-selective and selective herbicides.
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Replant to native plants at least 12 months after the last spray
Environmental Weed
Veldt Grass
Annual Veldt Grass
FACTS
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Perennial species
Can seed 5-6 times per year.
Highly opportunistic grass capable of overwhelming road verges and bushland.
Competes with natives
Seeds prolifically & is spread by wind or on the fur of animals
Prefers sandy soils
Serious fire hazard
Native to South Africa
Control
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Plants are easy to hand-pull, as roots are very shallow.
Flowering plants can be gathered with catcher mowers around the time of peak spring
flowering to minimise seed production.
Manual removal by slashing and grazing of infestations before seed set is important.
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Plants can be sprayed with non-selective or grass-selective herbicides over autumn-winter
before flowering stems emerge.
Prevent seed set for 2-3 years
Graze heavily and continually
Environmental Weed
Victorian Tea Tree
FACTS
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Has become a serious roadside weed and is invading bushland down south
Likes sandy & lateritic soils
Serious fire hazard
Forms dense colonies
Still sold in nurseries
From the Eastern States
Roots produce chemicals that reduce the growth of companion plants.
Control
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Hand-pull seedlings. Older seedlings tend to break off and regrow.
Small bushes tend to regrow when cut but older bushes tend to die.
Grazing will control seedlings.
Spot spray small plants
Bulldoze thickets, then burn when dry.
Environmental Weed
Watsonia
FACTS
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Garden escapees
Stiff upright leaves
Very serious weed in wetter areas especially roadsides, water courses, railway lines &
open woodland.
Chokes native vegetation
Serious fire hazard
Spreads & multiplies quickly from stem bulbils and underground bulbs (corms), birds &
water
Five species in the group
Introduced as a garden flower
Still sold in some garden catalogues
From South Africa
Flowers spring and early summer.
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Control
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Small infestations can be removed by hand pulling when soil moist and burn the corms and
bulbs. Thick infestations are difficult to control manually.
Seasonal bulbil formation can be prevented by slashing when the stems first emerge.
Where removal is not immediately possible spread can be limited by cutting the bulbil laden
stems away.
Grazing provides effective control.
Cultivation to 100 mm provides good control if done after the old corm is exhausted and
before new corms form or before the flower stem emerges. A follow up cultivation is usually
needed.
Mowing and slashing are usually ineffective unless repeated very regularly.
Start control at the top of the Catchment.
Eradication of an area can usually be achieved in 2-3 years.
Environmental Weed
Wattles
Acacia baileyana (Cootamundra Wattle),
Acacia iteaphylla (Flinder’s Range Wattle)
Acacia decurrens (Black Wattle)
Acacia elata (Mountain Cedar Wattle)
Acacia longifolia (Sydney Golden Wattle)
Acacia podalyriaefolia (Queensland Silver Wattle)
Acacia pycnantha (Golden Wattle)
Acacia dealbata (Silver Wattle)
Acacia melanoxylon (Blackwood)
FACTS
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Eastern State’s varieties
Planted in gardens, farm windbreaks or early rehabilitation work.
Some are particularly invasive
Most species listed above, live for twenty years or longer
Popular garden and public open space plant due to its easy cultivation
At least seven species which are seriously colonizing roadsides & bushland
Prolific seeders with seed able to survive many years.
Competes with native vegetation
Control
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Seedlings and small plants are easily hand-pulled or dug out. To prevent regrowth ensure the
roots are removed.
Younger plants can be treated using the cut-paint or drill-fill methods.
Fire destroys plants and stimulates seed germination for herbicide treatments or manual
removal.
Seedlings will need to be controlled for several years.
Avoid burning infestations unless there are sufficient resources for follow up work.
Seedlings and small plants can be sprayed with non-selective or selective herbicides. A
follow-up treatment on emerging plants is essential. Repeat treatment every 2-3 years.
If hand pulling, ensure roots are removed with the seedling by using a weeding fork.
Don’t buy or plant these species
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Environmental Weed
Wild Oats
Bearded Oat, Wild Oat, Ludo Wild Oat
FACTS
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Most serious weed found in cereal crops around the world
Opportunistic grass species
Increasing problem on disturbed land
Seed dispersal is airborne
From the Mediterranean region
Most serious weed found in cereal crops around the world
Control
Manual removal, regular mowing, grazing or spraying particularly in spring when seeds are
produced.
Prevent seed set for 3-5 years
Environmental Weed
Wild Radish
And Mediterranean Turnip, Turnip Weed, Hedge Mustard,
Indian Hedge Mustard, Wall Rocket, Sand Rocket (Lincoln Weed)
FACTS
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Persistent roadside & paddock weed and flourish in under grazed situations.
Common horticultural & agricultural weed
Economically one of the most important weeds of cropping
Seeds viable for a long time
Flowers are white, yellow or pink to mauve
Native to Europe and Asia
Common to roadsides and disturbed areas near cultivation but not often invading bush.
Flower from Autumn to Spring
Mature and set seed quickly
Once pods are formed, seeds will often mature even if the plant has been uprooted
Control
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Manual removal effective but must be done at least 8-10 weeks.
Many are unpalatable so grazing only offers partial control.
Isolated plants should be removed manually and burnt if flowering and seeding.
Plants can be sprayed with non-selective and selective herbicides.
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Environmental Weed
Willow
FACTS
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Weeds of national significance
Compete vigorously for space, water and nutrients eliminating all indigenous vegetation with
an infestation.
Broadly grouped into tree or shrub forms.
Leaves variable in colour and shape. Seed minute. Roots woody.
Reproduce by seed and vegetatively.
Seed is dispersed by wind and water.
Control
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Seedlings and small plants can be dug out. Tops are very likely to break away when pulled so
if root remain they should be dug out.
Plant less than 10 cm in diameter can be treated using the cut-paint method.
Seedlings, saplings and regrowth from failed cut-paint treatments, can be sprayed with nonselective herbicides. Follow up treatments may be required as plants sometimes re-shoot.
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