Linda and Roger's Southwater Downs
Weed Control Implementation

This is a page within Roger and Linda's Southwater Downs Web-Site.

This page contains information about the activities we've undertaken on the property to address weed problems affecting the rainforest on the property.

Here's what we've done most recently, and here's what we plan to do next.

We've also made some notes on the care needed when addressing a weed problem.

The Baseline

Following purchase of the property in 2002, we saw that the up-hill edges of the rainforest were under attack from blackberries. During 2003-04, we used a weeding contractor (commercial rather than conservation-oriented), who sprayed them, and dragged some of the largest bushes out.

During 2005-06, the Catchment Authority provided advice on native species in and on the edges of the forest, and the major weeds that needed to be attacked. At this stage, the blackberries were worse at the bottom of the property than at the top. We negotiated a contribution towards the fencing of the northern edge, a second round of blackberry attack, some initial work on the wandering jew, and plantings in the riparian grass area.

The fencing was done in 2007. In 2008-09, the blackberry-spraying and planting were conducted by a conservation-oriented contractor ('bush regenerator' rather than 'weeding contractor'). The work that was done was fine, but we weren't impressed with the value-for-money, nor with the failure to attack the wandering jew and to provide the required weed-list.

In early autumn 2010, we applied our 'cut-back, then cut-and-paint-every-cane' technique to the blackberries on the edges at the top, the bottom, and beside the path between them. The technique is discussed generally here and in more detail here. In late spring 2010, inspection suggested that we'd had a lot of success. We repeated it in 2011, with significant effect, and the same again in 2012. An annual attack is necessary, and the work is non-trivial; but it's within our capabilities and it's effective.

Here are baseline photos of the forest and forest-edges.

Activities To Date

The following activities have been conducted since 2008:

November 2008

April 2009

July 2009

13 Dec 2009

21 Mar 2010

22 Mar 2010

12 October 2010

The visit was primarily to work with the surveyor to mark out the boundaries of the area that is to be the subject of the Conservation Agreement.

I used the opportunity to do some experimenting with the Trad:

When we checked the bags 5 months later, they were deeply embedded in the re-grown Trad. And as the photos below show, the bagging was a failure, because the plants were alive, and shooting merrily. Clearly the bag needs to be not only black, but also out in direct sunlight.

Bagged Trad
Bagged Trad

The other activities were:

26 March 2011

Rubucide day for 2011 came after a moist and not-hot summer, and just after very serious rainfall in the area which had flooded Albion Park at the bottom of Macquarie Pass and washed out a bridge on the Jamberoo Road. The inspection was challenging because of the lushness of the grass (even by Robertson standards). What we found was:

The attack work conducted on the day was as follows (spraying with Grazon/Triclopyr, painting with Glyphosate):

27 March 2011

We finally ran the long-intended controlled experiment on Trad / Wandering Jew. For once we had four sets of hands, because we were assisted by Roger's sister Carole and her husband Peter Waters. It made a big difference. We spent from 11:30 until 16:15, with a short lunch-break. It was overcast with occasional light drizzle, and about 16 degrees.

We selected the flat area behind the stable.

It's partly within the back yard of the house, and partly within the Conservation Area.

The reasons for choosing this area were that:

  • the Trad is almost entirely on slopes and in forests. But this is the one area that's flat and hence an easier place to experiment
  • it's relatively free of low-flying branches and vines
  • we could do tests of the weedicides in somewhat degraded forest just outside the conservation area
Click on any image to enlarge it
Satellite Image

The Trad was 12-18 inches high and very thick.

Only occasional flowers were visible.

They were white, which confirmed that it was indeed Tradescantia albiflora and not the similar native.
Trad

We conducted three experiments.

They were in the three different areas, shown on the diagram.

The forest canopy in Area 1 is thin compared with the normal forest, and in Areas 2 and 3 it's lighter again.

Oops. The satellite image has north at the top, whereas the diagram has north at the bottom.
Sorry 'bout that.
Layout

1. Manual Treatment Experiment:

Area 1.
Looking West from J9
Looking South-West from J9
Before Clearance
Before / West
Before / SW
After Clearance
After / West
After / SW

2. Triclopyr Treatment Experiment:

  • We defined an area about 8m EW x 5m NW, outside the conservation area and close to the southern boundary-fence
  • We sprayed using 20ml of Grazon (Triclopyr) in 5 litres of water with a small amount of dishwashing liquid as surfactant
  • This was done when the plants were just a little moist from the mist
  • Triclopyr is a weedicide fairly specific to broadleaf plants, which has a moderately nasty residual which lasts for a few months
  • The photo is looking East from J2
  • The Trad has been somewhat trampled, because the spraying was done from 2 feet away
Area 2.

3. Glyphosate Treatment Experiment:

Area 3. Nth
Area 3. Sth

The pile of residue was put 15m away, in the horse-paddock:

Pile
Squashed
Covered

6 March 2012

Regrettably, we didn't manage to re-visit during the following 12 months, with the result that we couldn't monitor changes in the treated vegetation.

It was almost a year later when I did a quick recce, primarily to plan the 2012 rubucide day.

The areas we had worked on in March 2011 were completely smothered in trad. The only observations of note were:

We then contacted three potential weed contractors, with the idea that we would do some experimentation, and apply for a grant from the Private Land Conservation Grants Program for Community Bush Regeneration (current round closing 15 April). A better URL may be the Foundation for National Parks and Wildlife (FNPW) itself.

These two were no-bids:

The only positive response was from:

Gerard emailed back:

However, Gerard is away for a month, and then we go, so it will have to wait for a while.

(We also heard from Brett, the tenant, that a mate had successfully attacked Trad with a mix of diesel with a fairly small amount of salt – or was it sugar? – a ratio something like 10 litres to a couple of cupsful).

7-8 April 2012

We did a 2-day x 5-hour working weekend on Easter Saturday and Sunday. It was entirely focussed on blackberries, although we did cut-and-paint a dozen large inkweed at forest edges. We saw only a couple of verbascum, and only a couple of old thistles and first-year rosettes. We found some ivy again near the concrete blocks on the right-hand side of the upper path, and cut-and-painted four small vines.

The 2011 blackberry attacks with both cut-and-paint and spray had been very effective. There was plenty of work to do this year, but there were fewer plants than in 2011, and only one patch remained that was too large for cut-and-paint attack.

On the first day, we started at the bottom part of the property. Linda did the cutting-and-painting of the large number of small plants in the riparian zone and the lower slopes. Roger worked the forest-edge, mainly on the northern end (the right as you look down at the creek). The central area contains the remaining large infestation. The bottom of the path on the right appeared to have been effectively cleared last year.

We then came up to the forest edge below the paddock. Linda did the open areas. Roger went into the forest and came back out to the forest edge from within. The native re-growth on the forest-edge has been very substantial, making it difficult going. The blackberries comprised vigorous single- and double-strands, many growing from old roots; but nothing like the tightly-entangled infestations of the past.

On the second day, Linda loaded up with 10 litres of water plus 50ml Grazon/Triclopyr. She sprayed:

Roger went back to the top of the forest beneath the paddock and attacked isolated blackberries that could be reached from outside the forest, plus a small patch of inkweed amongst the vigorous native re-growth. There was also one low, grass-entangled infestation just below the stable-paddock gate, which took quite some time and 30 cuts.

The large paddock still has many blackberries that need to be sprayed next year.

'First, do no harm'

Two important aspects of conservation are distinguishing between weeds and not-weeds, and avoiding doing more harm than good. The rule is to not touch it unless you know what you're doing. That has two components:

A nice case study from Southwater Downs is a Senecio, which we think is S. linearifolius (Fireweed Groundsel). PlantNet identifies 72 species in the Genus in Australia, of which 9 are Introduced (i.e. generally, weeds), and several seriously so. They include Senecio madagascariensis, which is declared noxious in much of the Southern Tablelands and SouthEast Region.

The plant we have is a pioneer, vigorous, looks like a weed, and, if we've identified it correctly, its common name has the word 'weed' embedded in it. But it's a highly desirable local.

In the words of SouthEast Weeds, "... the native "fireweed groundsel" (Senecio linearifolius) ... is a robust species to over a metre in height, which grows as a cluster of stiff stems. 'Petals' are shorter and fewer (8 or less) than in fireweed [S. madagascariensis] and leaves are much larger, with the veins conspicuous on the upper surface and the margins finely and regularly toothed and slightly rolled under. This difference in the leaves is apparent in the seedlings as well. This species is an opportunistic coloniser of bare ground and may give some cause for alarm by behaving in a weedy manner after disturbances such as clearing of forest, fire or drought".

Future Activities

Our general approach to weed management, and specific approaches to particular species, are explained in the Weed Management page within our Bunhybee web-site.

In roughly descending priority order:

This is a page within the Southwater Downs Web-Site, home-page here

Contact: Linda or Roger

Created: 22 March 2010; Last Amended: 11 April 2012