Weed Spotter Newsletter
Issue Number : 9 Autumn 2010
Inside this issue
- State prohibited weed— Mexican feather grass
- Update on Mexican feather grass
- Weed Spotter finds a rogue Mexican in the basin
- State prohibited weed— Water hyacinth
- A good report A bad prize!
- State prohibited weed— Hawkweed
- Hawkeyes at Falls Creek Wild dog controllers trained
- Update on—State prohibited weeds
- Alligator weed
- Backyard audits Regional infestations Riparian metropolitan sites
- Giant knotweed
- Vigilance pays off!
- Know your local WACO
Current Weed Spotters
Welcome to the Autumn 2010 edition of the Weed Spotter newsletter. There are currently 2444 registered Weed Spotters in Victoria. As a Weed Spotter, if you have any ideas or information you would like to see in these newsletters please let your local Weed Alert Contact Officer know and we will try to include it in the next issue.
Salvinia found in Port Phillip dam
Annie Lamb & Kylie Woods Weed Alert Contact Officers
The first Port Phillip catchment salvinia site to be found in a dam was reported by a diligent land owner at Kangaroo Ground. All eight previous salvinia sites within the Port Phillip region were in tubs or ponds.
Salvinia (Salvinia molesta) is an aquatic fern that floats on the water surface. It can grow rapidly, particularly in humid weather. Large infestations of salvinia can block waterways, decrease water quality and reduce sunlight penetration.
It is sometimes confused with azolla although leaf shapes are very different. Azolla has a fern shaped leaf which turns a pink-red colour, whereas salvinia is bright green turning brown when it dies off.
The landowner received different water plants from a friend for his dam nine months ago and watched as one plant in particular began to expand at an alarming rate in early summer. It turned out to be salvinia, which quickly spread from one corner of the dam to cover the whole surface of the 35 metre wide dam in about six weeks.
During the clean-up 18 trailer loads of salvinia plants were removed from the dam. Department of Primary Industries (DPI) is now working with the landowner and contractors to remove all traces of salvinia from the dam. Trace back investigations led DPI staff to the provider of the salvinia plants. Officers inspected the property and removed salvinia from four ponds, a fish tank and a wheelie bin.
This outbreak identifies the highly invasive nature of salvinia in a water body when the conditions are right.
 |
 |
| Dam without salvinia | Dam with salvinia |
State prohibited weed: Mexican feather grass
Update on Mexican feather grass
Richard Plant Incursion Controller
The threat of Mexican feather grass (Nassella tenuissima) becoming naturalised and impacting on Victoria’s environment, economy and recreation has been significantly reduced as a result of a major effort by Department of Primary Industries (DPI).
Mexican feather grass is a high risk weed in Australia with the potential to invade more than 505 million hectares nation wide (about 65 per cent of the country).
Mexican feather grass is a densely tufted, perennial tussock that grows to about 70cm high. Its leaves are needle like and roll smoothly between the thumb and forefinger. Serrations make the leaves feel coarse when sliding fingers down the length of the leaf blade. Mature plants form seed in a contracted flower head. Seeds have a small pointed tip and a long bent tail which resemble a large feather when clumped together at the end of the flower spike.
Biannual monitoring and treatment activities will be on-going for the infestation sites as plants can produce seed in both spring and autumn. Despite the drought like conditions over the 2008/09 summer, seed germination was observed at most sites.
Weed Spotters are an important group in identifying Mexican feather grass in suburban situations and alerting the DPI to potential new infestation sites. If you think you have seen a Mexican feather grass plant contact DPI on 136 186.
 |
 |
| Mexican feather grass (Nassella tenuissima) |
Mexican feather grass (Nassella tenuissima) |
Weed Spotter finds a rogue Mexican in The Basin
Lana Smart Weed Alert Contact Officer
 |
|
Mexican feather grass in a garden |
Department of Primary Industries (DPI) officers received a report of Mexican feather grass growing in a garden in the outer eastern Melbourne suburb of The Basin. A Weed Spotter called the customer service centre on 136 186 to make the report.
Recollecting the distinctive feathery flower head pictured in the Weed Deck, the Weed Spotter was able to recognise the Mexican feather grass plants from the footpath. Officers from DPI then confirmed the report and removed three mature plants from the front garden of the home.
With the neighbouring Dandenong Ranges National Park close by, which could easily be invaded by this grass, this was a really important report.
This was one of many calls received by DPI from concerned and interested members of the public which have uncovered 15 new Mexican feather grass infestation sites.
State prohibited weed: Water hyacinth
A Good Report
 |
|
Water hyacinth roots |
A Good Report Hannah Cooke Weed Alert Contact Officer
Late February an infestation of water hyacinth was reported in a residential lake at Ocean Grove after about 50 plants were spotted by council contractor staff. Not recognising the unusual water plant they took a specimen back to their offices to identify.
Once they worked out what the suspicious plant was, they reported it to their council contact who, being a weed spotter, called the local Weed Alert Contact Officer.
The site has now been treated, while trace forward and trace back processes are still being carried out to determine the source of the infestation.
“DPI officers coordinated an awareness raising effort consisting of visiting more than 600 houses in Mallacoota” |
A Bad Prize!
Drew Sutton Weed Alert Contact Officer
 |
|
Water hyacinth (Eichhornia crassipes). |
Residents in the Mallacoota area are being asked to report infestations of water hyacinth after it was discovered in the area.
The discovery was reported to a Department of Primary Industries (DPI) officer in February during a local community meeting. The concerned resident reported four ice-cream containers, each with a number of water hyacinth plants, had been donated as prizes for a community bushfire fundraising appeal about twelve months ago.
DPI investigations located one of the winners and positively identify the plants as water hyacinth. However, it is believed a number of other land owners within Mallacoota and surrounding areas may have this environmentally damaging species.
DPI officers coordinated an awareness raising effort consisting of visiting more than 600 houses in Mallacoota and surrounding areas. 11 infestation sites were found and more than 200 water hyacinth plants removed.
An infestation of salvinia was also discovered during the local door to door enquiries.
State prohibited weed: Hawkweed
Hawk eyes at Falls Creek
 |
|
Weed Spotters involved in surveys at Falls Creek |
 |
|
Weed Spotters involved in surveys at Falls Creek |
Kerrie Howe Incursion Controller
Once again Weed Spotters had the opportunity to be involved in the annual hawkweed survey at Falls Creek in Victoria's Alpine region.
Hawkweeds are extremely invasive plants with a number of species already being problem weeds in New Zealand and other countries. Hawkweeds have the potential to severely damage our Alpine areas by out-competing native grasses and wild flowers.
Staff from Department of Primary Industries (DPI) and Parks Victoria as well as 18 Weed Spotters braved the elements to complete a successful search for this invasive plant during January. Results of the survey indicated hawkweed was decreasing in regularly surveyed sites, although a number of new sites were found in areas not previously known to be infested.
There are two species of hawkweed known in the Falls Creek region - orange and King-devil.
Orange hawkweed has bright orange flowers that grow in clusters of five to 10, while King-devil hawkweed is distinguishable by its longer stems and leaves, and clusters of yellow flowers.
If you are a Weed Spotter and would like to be involved in future Weed Spotter surveys, keep an eye out for emails advertising these events.
“There are two species of hawkweed known in the Falls Creek region -orange and King-devil.” |
Wild dog controllers trained
 |
|
Orange hawkweed (Hieracium aurantiacum) |
Drew Sutton Contact Officer
The Department of Primary Industries (DPI) Gippsland wild dog controllers have greatly expanded their knowledge of Victoria’s State prohibited weeds after undertaking Weed Spotter training in November last year.
The wild dog controllers undertook introductory training a year ago and wanted to refresh their identification skills prior to the peak flowering season for most of the State prohibited weeds.
The two hour training session focused on plant biology and included a case study on hawkweed.
The wild dog controllers will be a great asset and increase the chance of finding new infestations as they cover thousands of hectares on public and private land while they go about their duties.
Update for State prohibited weeds
Fran Hausmann Senior Incursion Controller
Alligator weed
 |
| Alligator weed (Alternanthera philoxeroides) |
 |
| Removal of Alligator weed at Edwardes Lake Park |
The state-wide alligator weed monitoring and treatment program is progressing well with the inspection of about 700 Melbourne backyards where records indicate alligator weed infestations had been found. A number of creeks and water ways in urban and rural Victoria were also inspected and treated. Several new infestations were detected this season through Department of Primary Industries (DPI) surveillance networks.
Backyards—The backyard audit involves up to 12 DPI Weed Alert staff visiting residential properties throughout Melbourne and treating alligator weed. Four weeks into the operation have shown about 40 per cent of the sites still have alligator weed. There has been an overall good response from the landholders associated with the audit and treatment.
Regional infestations—Infestations at Warragul and Bendigo were treated using mechanical excavation. This approach removes the entire infestation, including the roots. Follow-up monitoring will continue at these sites to treat any emerging plants.
Riparian metropolitan sites—Treatments of the infestations in and around Melbourne waterways are underway. Treatment is being coordinated using a top-down approach with upstream infestations treated first to limit re-infestation. A variety of methods are being used.
Alligator weed is a significant problem throughout Victoria and it is important to report any sightings of alligator weed to DPI on 136 186.
“Alligator weed is strategically treated using a top down approach.” |
Giant knotweed: Vigilance pays off!
Kate Cunnew Weed Alert Contact Officer
The giant knotweed (Fallopia sachalinensis) site at Narbethong is one of only four known infestations in the state. The Narbethong site was reported in 2001 when concerned landowners asked Parks Victoria and Department of Primary Industries (DPI) to identify the weed in their garden. The giant knotweed by this stage had formed dense thickets in several areas of the garden.
Since its discovery, DPI has been treating the site every summer, slowly reducing the area of the weed. In 2008 only a single shoot was found and treated. The weed has not emerged since.
Knotweeds (both Giant and Japanese) are vigorous weeds that smother other vegetation by forming dense leafy thickets. The rhizomes of knotweeds are incredibly strong and able to penetrate thick asphalt. Knotweed foliage dies off over winter and new shoots emerge again in the warmer weather, especially after summer rains.
Giant knotweed can be identified by its large leaves, 10 to 25cms wide and 15 to 40cms in length, with heart shaped bases. The stems are hollow and may be red in colour when young and become brown and woody with age. Giant knotweed has green-yellow flowers from December to February.
Although the infestation cannot yet be classified as eradicated (knotweeds have been known to re-emerge for up to five years following treatment), the lack of any plant material for the last two seasons is great news and signals the likely ultimate success of this program.
 |
 |
| Giant knotweed site at Narbethong 2001 |
Giant knotweed leaf |
Know your local Weed Alert Contact Officer
| Name | Region | Location | Phone | ||||||
|---|---|---|---|---|---|---|---|---|---|
|
1. Kate Cunnew | Goulburn Broken | Seymour | 03 5735 4300 |
|
||||
| 2. Robert Metcalfe | Mallee | Mildura | 03 5051 4327 | ||||||
| 3. Julie Graham | North Central | Kyneton | 03 5421 1722 | ||||||
| 4. Bronwyn Grass | North Central | Bendigo | 03 5430 4426 | ||||||
| 5. Greg Johnson | North East | Wodonga | 02 6043 7967 | ||||||
| 6. Drew Sutton | East Gippsland | Bairnsdale | 03 5152 0645 | ||||||
| 7. Kim Gowers | West Gippsland | Leongatha | 03 5662 9919 | ||||||
| 8. Pam Allan | West Gippsland | Ellinbank | 03 5624 2272 | ||||||
| 9. Annie Lamb | Port Phillip East | Frankston | 03 9785 0109 | ||||||
| 10. Kylie Woods | Port Phillip East | Attwood | 03 9217 4240 | ||||||
| 11. Roger MacRaild | Port Phillip West | Bacchus Marsh | 03 5366 0024 | ||||||
| 12. Julie Gooding | Port Phillip West | Bacchus Marsh | 03 5366 0022 | ||||||
| 13. Hannah Cooke | Corangamite | Geelong | 03 5226 4560 | ||||||
| 14. Lucy Ivey | Wimmera | Horsham | 03 5362 0787 | ||||||
|
|||||||||
To update your contact details including your email address or report a serious new weed contact your local Weed Alert Contact Officer on the number above or through the DPI Customer Service Centre on 136 186. Details can also be found on the DPI website: www.dpi.vic.gov.au/weedspotters
