This is a page within Roger and Linda's Bunhybee Grasslands Web-Site.
Bunhybee Grasslands is a 49 hectare / 120 acre conservation property 35km south of Braidwood, in southern N.S.W.
You can follow through the internal links, or you may find it easier to use the Site-Map.
This is a subsidiary page to the Action Plan. It contains generic information on relevant weeds and what to do about them. The sections are:
Note that this page was prepared in a specific context, for a specific purpose: to assist in managing a native grassland property, in the Southern Tablelands of N.S.W., which is subject to conservation protection, and which has comparatively quite small weed-problems. In other circumstances, the appropriate categorisations, principles, attack methods and practicalities may be rather different.
In the context of a conservation property, a weed is an 'exotic' species (i.e. is not native to the area).
Appropriate approaches to managing weeds reflect both their own nature and how serious a threat they represent to the purposes of the property.
A weed is a serious threat if it has the tendency to spread, to spread rapidly, and to dominate local species. Relevant examples include serrated tussock and blackberry. (In other contexts, a wide range of species are important, such as ivy, lantana, privet, cotoneaster, bitou bush, Chilean needle grass, willow-trees and radiata pine).
A weed is a threat if it has a tendency to spread, and to dominate local species. Relevant examples include a number of exotic grasses (including Yorkshire fog and sweet vernal grass), thistles, briar (rose-hips) and fleabane.
A weed may be tolerated if it exists in low volume, has little tendency to spread, and/or does not dominate or displace local species, and especially so if it is an early coloniser of disturbed ground and thereby helps fight more serious weed species. Relevant examples include dandelions. We're unsure at this stage about European sorrel and paspalum.
1. Think before acting, because addressing one threat may create or exacerbate a vulnerability to another threat (e.g. when the weed has gone, will its absence result in erosion, and what will replace it?)
2. Act early enough to prevent regeneration (e.g. for some species, an early-spring attack is essential)
3. Control the means of regeneration (especially seeds, in some cases roots)
4. Avoid significant 'collateral damage' (e.g. to native species or the ground in the vicinity, and to waterways)
5. Avoid contamination (e.g. by putting cuttings on hitherto weed-free ground, or by spilling herbicide)
6. Select the method in order to balance effectiveness against negative impacts
7. Attack vigorous outliers before tackling the main infestation (i.e. first limit the threat, then progressively remove it)
These are inevitably rough and have substantial negative impacts that create or exacerbate vulnerabilities that need to be managed. But with major infestations they may be essential.
Slashing. Works as the first phase of an attack on large infestations. Machinery needs to be cleaned before and after to avoid cross-contamination of areas treated before and after the work
Area Treatment. Works for weeds for which a very specific herbicide exists, that won't harm native species in the area
Competitor-Planting. Depends on finding and encouraging a sufficiently vigorous native species that will flourish alongside the weed and gradually displace it
Biological Controls. Insects and fungi may be introduced to attack particular weeds; but this is a government decision rather than one used by land-owners
These are inevitably expensive in time as well as money, but are more likely to be effective on scattered and low-level weed-problems.
Hand-Pulling. Works for weeds that will come easily out of the ground, without leaving significant broken ground that will be colonised by more (and perhaps worse) weeds. Ineffective and even harmful in the case of plants with deep, widespread or running roots, or in hard soil
Plant Cutting. Works for weeds that do not regenerate from rootstock, or if used in conjunction with means to prevent regeneration from rootstock, e.g. it may require the remaining base of the plant to be broken and/or poisoned
Plant Treatment. Uses poison, which risks the health of other plants and the worker. Works if applied carefully, on appropriate weeds, using appropriate chemicals and techniques. If used long-term, risks the emergence of herbicide-resistant weeds
Serrated Tussock (Nassella trichotoma) and see the photos at the Bega Valley Plant Index
Blackberry (Rubus fruticosus spp. agg.)
Black Thistle (Cirsium vulgare). This is a biennial, which grows a rosette in its first year, and a stem in its second. It can produce large numbers of buds, each of which contains large numbers of seeds (c. 50?), which float clear of the dying flower and mostly fall close by. The species is cunning in that it typically has one early flower, followed by a succession over the summer and autumn. Green buds and the bowls beneath the purple flowers contain seeds; but old, open heads have probably already released them. The plant appears to reliably expire after its one season of fruiting:
Mature, unopened heads
... showing viable seed ...
... still inside
Old heads, after releasing seed
We've mainly worked out the following treatment methods for ourselves, but an excellent US Forest Service source that we've found since has confirmed most of our thinking:
Nodding Thistle (Carduus nutans) and Common Sow-Thistle (Sonchus oleraceus)
Sweet Briar / Briar Rose (Rosa rubiginosa)
Fleabane (Conyza bonariensis) and see the photos at the Bega Valley Plant Index
Sorrel (Rumex acetosella and/or Acetosella vulgaris?) and see the photos at the Bega Valley Plant Index
This section draws on various verbal advice and in particular on Muyt (2001, pp. 23-32).
The cut-and-paint technique is designed to "introduce a systemic herbicide to the internal water-nutrient transport system so that the chemicals circulate through to the roots and kill the plant" (Muyt p. 28). It uses poisons, so care is needed.
The technique's effectiveness depends on the activity of the plant itself, and hence it should not be used:
and hence should be used at times such as early and late on spring days.
In the case of blackberry in particular, it's most effective in late summer and early autumn, because the plant is drawing fluids back into the roots for winter and draws the poison with it, killing the roots.
The description below reflects our main priority at the time it was written, which was blackberry.
The technique is as follows:
AG (2008) 'Weed species A-Z' Department of the Environment etc., 2008, at http://www.weeds.gov.au/cgi-bin/weedspeciesindex.pl?id=701
Bega Valley Plant Index, at http://www.thebegavalley.org.au/plants.html
CHAH (2008) 'Australian Plant Census (APC)' Council of Heads of Australasian Herbaria (CHAH), 2008, at http://www.chah.gov.au/apc/about-APC.html (Incomplete List of Common Names)
CHAH (2008) 'Australian Plant Name Index (APNI)' Council of Heads of Australasian Herbaria (CHAH), 2008, at http://www.cpbr.gov.au/apni/index.html (Less incomplete List of Scientific Names)
DPI (2007) 'Noxious and environmental weed control handbook' N.S.W. Department of Primary Industry, 3rd edition, April 2007, at http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0017/123317/noxious-and-environmental-weed-control-handbook-3rd-edn.pdf (1.8MB)
DPI (2008) 'Weeds' N.S.W. Department of Primary Industry, at http://www.dpi.nsw.gov.au/agriculture/pests-weeds/weeds
DPI (2010) 'Noxious weed declarations for Palerang Council' NSW Department of Primary Industry, at http://www.dpi.nsw.gov.au/agriculture/pests-weeds/weeds/noxweed/noxious-app?sq_content_src=%252BdXJsPWh0dHAlM0ElMkYlMkZ3d3dpLmFncmljLm5zdy5nb3YuYXUlMkZ0b29scyUyRnZpZXdjb3VuY2lsLmh0bWwmYWxsPTE%253D&council_id=89
FOG (1999-) 'Newsletter', Friends of Grasslands, 1999-, at http://www.fog.org.au/newsletter.htm
IEWF (2008) 'Common Invasive Plants in Australia' International Environmental Weed Foundation (IEWF), 2008, at http://www.iewf.org/weedid/index_by_reserve.htm
Muyt A. (2001) 'Bush Invaders of South-East Australia' R.G. and F.J. Richardson, 2001, 304 pp., c/- email@example.com
NCT (2008) 'Plan of Management for Bunhybee Grasslands' undated c. June 2008 (50 pp.)
SEW (2010) 'South-East Weeds' Southern Tablelands and South Coast Noxious Plants Committee, at http://www.southeastweeds.org.au/index.pl?page=1
Weeds Aust (2006?) 'Weed Identification – South Eastern Highlands' , date unclear perhaps 2006, at http://www.weeds.org.au/cgi-bin/weedident.cgi?tpl=region.tpl&state=nsw®ion=seh
Weeds CRC (2005) 'Herbicides: knowing when and how to use them ' Cooperative Research Centre for Australian Weed Management, at http://www.weedscrc.org.au/documents/gl02_herbicide_use.pdf
Weeds CRC (2008) 'Individual Species' Cooperative Research Centre for Australian Weed Management, site frozen at 30 June 2008, at http://www.weedscrc.org.au/weed_management/indiv_species_a.html
This is a page within the Bunhybee Grasslands Web-Site, home-page here, and site-map here
Contact: Linda or Roger
Created: 14 December 2008; Last Amended: 22 November 2010