Linda and Roger's Bunhybee Grasslands

Weed Management Resources

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:

• Weed Categories
• Weed Management Principles
• Weed Attack Methods
  • Area Methods
  • Plant-by-Plant Methods
  • Generic Description of the Cut-and-Paint Technique
• Sources

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.

Companion pages to this page are:

• our Weed Control Plan
• our Weed Control Implementation reports

Weed Categories

The meaning of 'weed' is relative to context. For example, a domestic gardener and a farmer apply the term rather differently. In the context of a conservation property, a weed is an 'exotic' species, meaning that it is not native to the area. An Australian native may be a weed, if it is out-of-area (e.g. Cootamundra wattle, in many parts of Australia).

However the term is mainly used to refer to problem plants, rather than to plants that do little harm. Appropriate approaches to managing weeds reflect both their own nature and how serious a threat they represent to the purposes of the property.

~ Serious Threats

A weed is a serious threat if it has the tendency to spread, to spread rapidly, and to dominate local species. Relevant examples in our area include serrated tussock, African love-grass (as distinct from the native cousins in the Eragrostis genus) and blackberry. In other contexts, a wide range of species are serious threats, such as ivy, lantana, privet, cotoneaster, bitou bush, Chilean needle grass, willow-trees and radiata pine.

~ Threats

A weed is a threat if it has a tendency to spread, and to dominate local species. Relevant examples for us include a number of exotic grasses (including Yorkshire fog and sweet vernal grass), thistles, briar (rose-hips) and fleabane.

~ Minor Concerns

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 keep out more serious weed species. Relevant examples include dandelions. We're unsure at this stage about European sorrel.

Weed Management Principles

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 the banks of 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)

Weed Attack Methods

~ Area Methods

These are inevitably rough and have substantial negative impacts that create or exacerbate vulnerabilities that need to be managed. But with major infestations these methods may be essential.

Slashing. This may be effective as the first phase of an attack on large infestations. Machinery needs to be cleaned before and after use to avoid cross-contamination of different areas

Area Spraying. This may be effective for weeds for which a very specific herbicide exists, which targets that plant but will do little harm native species in the vicinity

Pattern-Burning. Low-intensity fires may seriously harm foreign species and advantage native species. This depends on the assumptions that native species have a generally greater capacity to cope with fire, and that the native-species 'seed bank' in the burnt area is more intensive than the weed seed bank. This appears to be a potential treatment for some foreign grasses, and perhaps for local grasses that are threatening to become dominant, such as Themeda australis

Crash Grazing. In many cases, weeds may be more attractive to grazing-stock than natives are. Collateral damage has to be managed, however. The most significant risk is the import of weeds both on them and in them. To reduce seed-import in dung, stock needs to be held in a bare paddock for at least a day – which requires hand-feeding. There are also risks to the ground surface, particularly at congregation points like water supplies and gateways. Particularly vulnerable ground and plants need to be fenced off in advance of the grazing taking place. There are also risks to fencing, and risks that the seldom-tested fencing may prove to be inadequate to keep the stock enclosed. If the stock is being agisted for an extended period, the stock's owner may be happy to take responsibility for the fencing and stock management; but conservation sites are likely to need only short ('crash') grazing by a moderately large herd or mob, in which case it's not worth the stock's owner investing much time or money in checking and mending fences

Soil Treatment. Various interventions may have an impact on aspects of the soil in a way that disadvantages weeds and/or advantages natives. For example, Lunt (2011) reported that sugar treatment had a substantial negative impact on broad-leaved weeds

Competitor-Planting. This 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

~ Plant-by-Plant Methods

These can be highly effective, but are inevitably expensive in time as well as money. They are more likely to be effective on scattered and low-level weed-problems.

Hand-Pulling. This 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. It is ineffective and even harmful in the case of plants with deep, widespread or running roots, or in hard soil

Plant Cutting. This works for weeds that do not regenerate from rootstock, or if it is used in conjunction with means to prevent regeneration from rootstock, e.g. by breaking or chopping into the remaining base of the plant so that it dries out

Plant Cut-and-Paint. This works very well on some perennial woody weeds, such as blackberry and briar rose. By cutting the stems and immediately painting them with poison (preferably within 2-3 seconds, but perhaps up to 30 seconds), the plant can be encouraged to draw the poison down, killing the roots. See the technique description below

Plant Poisoning. Poison can be applied to specific plants in several ways. Poison risks the health of other plants and may risk the health of the worker. If used long-term, it risks the emergence of herbicide-resistant weeds. The techniques that we're familiar with are:

• Narrow-band Spraying. This can work if the arc from the nozzzle is very narrow, the nozzle is placed very close to the target-plant, the target-plant is not too closely intertwined with sensitive native species, the spraying is applied in sufficiently still conditions and carefully, on appropriate weeds, using appropriate chemicals and techniques

• 'Zelma's Method'. Wear protective (plastic or rubber) gloves beneath an outer layer of material gloves. Alternately dip the outer gloves in poison and rub them onto the targeted plants.

The Cut-and-Paint Technique

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:

• at hot times of day
• when plants are under stress, in particular in drought
• in low-growth phases, particularly winter

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:

• For large bushes:
  • do a preliminary prune to expose every cane for treatment
  • remove the cuttings to a pile. A rock-shelf is ideal. Failing that, the pile needs to be re-visited the next season, to deal with any shoots that may arise from the cuttings
• Cut the offending plant
  • Generally, secateurs are likely to be the best tool
  • Preferably cut the plant low down, close to the ground
  • Try to make the cut horizontal, so that the herbicide will not run off the surface
  • Cut and paint every cane. Don't assume that some canes are common to a single root
  • Access to all canes may be challenging, due to the terrain, undergrowth, or the size or nature of the infestation
• Remove any soil from the cut surface
• Apply the herbicide, very promptly
  • Apply it with a narrow-headed paint-brush, a dabber bottle, a hand-held spray-bottle with a very narrow and weak spray, or an eye-dropper
  • Concentrate it on the outer rim of the stump (where the action is), not the 'heart-wood'
  • Possibly apply it to some leaves below the cut as well, esp. fresh, young ones
  • Apply it within 2-3 seconds and not later than 30 seconds, before the wound starts to heal
  • Commonly, the herbicides used are glyphosate (e.g. Roundup) and/or fluoroproponate (e.g. TaskForce). They have different characteristics and are often used together, although some references say that fluproponate is effective in spring (only?). We strongly prefer glyphosate-only, because it has a short life and hence collateral damage to native species is minimised
• Manage the cuttings
  • Remove them from the site, or place them so that they have little chance of regenerating, e.g. on or under sheeting or on rocks, not on fertile ground
  • If the cuttings carry viable seed, take extra care
• Return the following season
  • Re-apply the method to any new growth
  • There may be a need to use complementary techniques to sustain the attack, e.g. raking and burning
• Return and check re-growth
  • The weed may re-generate, or some other weed may take advantage of the space
  • Blackberry will generally require multiple re-visits to the same location. It is in any case continually re-invasive because of carriage of seeds by birds and water, and a location that has been infested once is fairly likely to be later re-infested

Sources

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

Beemster M. (2005) 'The Woodland Web: A Sweet End to Weeds', CSU, December 2005, at http://www.csu.edu.au/herbarium/woodlandweb/restoration/sweet_end_to_weeds.htm

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) SUPERSEDED BY DPI (2011)

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

DPI (2011) 'Noxious and environmental weed control handbook' N.S.W. Department of Primary Industry, 5th Edition, October 2011, at http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0017/123317/Noxious-and-environmental-weed-control-handbook.pdf (3.3MB)

FOG (1999-) 'Newsletter', Friends of Grasslands, 1999-, at http://www.fog.org.au/newsletter.htm

FOG (2005?) 'Weeding to restore and protect your patch' Friends of Grasslands, 2005?, at http://www.fog.org.au/Brochures/weeding.htm

Greg (2010?) 'Weed Control' Greg's Indigenous Plants & Landscapes, 2010?, at http://www.gregsindigenouslandscapes.com.au/Weed%20Control.htm

Herbiguide (2013) 'The Pesticide Expert on a Disk', at http://www.herbiguide.com.au/InformationWeeds.aspx

IEWF (2008) 'Common Invasive Plants in Australia' International Environmental Weed Foundation (IEWF), 2008, at http://www.iewf.org/weedid/index_by_reserve.htm

Lunt I. (2011) 'From Weeds to Wildfire: Restoring Woodland Understoreys #3', Ian Lunt's Ecological Research Site, 26 February 2011, at http://ianluntresearch.wordpress.com/2011/02/26/restoring-woodland-understoreys-3/

Molonglo (2008) 'Weed Control Methods' Molonglo Catchment Group, 2008. at http://www.molonglocatchment.com.au/Weeds/control_methods.htm

Muyt A. (2001) 'Bush Invaders of South-East Australia' R.G. and F.J. Richardson, 2001, 304 pp., c/- richardson@weedinfo.com.au

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: 30 August 2013