Birdie’s Dell is on the mend

We’ve now spent well over a year at Birdie’s Dell and we are starting to see progress.

Each month we have been treating the Himalayan honeysuckle that is dotted through the long finger of peat wetland. In winter the honeysuckle loses its leaves and the remaining green stems are hard to spot hidden amongst the grasses and sedges. Come spring the bright green new shoots stand out, and the race is on to remove flowers and any seeds.

These honeysuckles in May have a slightly golden colour and are about to lose their leaves in winter.
These honeysuckles in May have a slightly golden colour and are about to lose their leaves in winter. While they have already dropped their seeds, it’s still useful to remove them to prevent a new batch of seeds next spring.

Morning tea break is perhaps the highlight of the session. We can sample each other’s treats, whether it is fruit cake, home baked slice or the obligatory ginger nuts. And we can share news and views, and get worked up about the latest environmental threat. Many of our crew are seasoned environmental campaigners, so we’re also plotting and scheming.

A sunny lunch spot in Birdie's Dell.
A sunny lunch spot in Birdie’s Dell, the kneeling mats preventing a wet bottom from the soggy ground.
The obligatory ginger nuts.

We have now removed all the obvious honeysuckles to a point 80 metres downstream from the top of the wetland. It is satisfying to see the native vegetation closing in on areas that once had large tufts of weeds.

Looking west down Birdie’s Dell. Our crew is slightly left of centre, pictured below. When we began over a year ago, this scene would have been full of Himalayan honeysuckle.
Bushcarers hard at work.

During warmer summer days we have been avoiding the open wetlands and instead remove weeds from the bushland adjacent to Cliff Drive on the southern side of Birdie’s Dell.

The road impacted by the landslip at the start of Narrow Neck is now repaired and we will be soon allowed into the bush along Glenraphael Drive. While Birdie’s Dell still has work to do, we are keen to get back to our home base at Narrow Neck to see which weeds have returned after a two-year absence.

A second home away from the landslides

Narrowneck Bushcare has been allocated a second home at Birdie’s Dell while we wait for the uncertainty about access to Narrowneck to be resolved following the March 2022 heavy rain and landslides.

The area that needed our attention was a side creek of Megalong Creek, that begins at Bonnie Doon (the south west gully near the junction of Bathurst Rd and Narrow Neck Road). Our creek drained an area behind a handful of houses sandwiched between the section of Cliff Drive that takes you to Cahills Lookout and Nelson Road.

An old map of Katoomba found on Dave Noble’s website named this area Birdie’s Dell, the swamp before the creek leaps over the cliff at Silver Spray Waterfall.

Historic sketch map of Katoomba showing Birdie’s Dell centre left, where we found large areas of Himalayan honeysuckle that needed our attention.

For several of our monthly sessions in late 2022 we removed Ivy and an assortment of weeds including Himalayan Honeysuckle, Agapanthus, Holly and Privet from an area adjacent to Cliff Drive (council land at 304-320 Cliff Drive).

Our bushcare site for a few months adjacent to Cliff Drive leading to Cahills Lookout. Weeds had emerged over many years from dumped garden waste and runoff from nearby urban areas.

Then in February 2023 we ventured deeper downstream into the trackless valley of Birdie’s Dell, leaving the road at a Sydney Water pumping station. We were seeking confirmation of a heavy infestation of weeds in the main swamp.

After gingerly walking steeply through a tough band of thick ferns, tea tree and banksia near the main creek line, we burst into the narrow open valley of sedges and other water-loving plants. Unfortunately it was heavily infested throughout with large Himalayan Honeysuckle.

The valley of Birdie’s Dell, showing Himalayan Honeysuckle dotted throughout.

Ahead of us was many months’ work in this otherwise delightful valley. This would be an ideal site for sunny winter days.

Keith and Andrew walked the full length of the open valley, about 300 metres, until reaching the national park boundary. About 50 metres before the boundary they were shocked to see massive erosion caused by last year’s heavy rain. It had undercut the peat causing slumping and 2 metre trenches eroded to the bedrock. Is this what will happen to the Blue Mountains swamps with more extreme rainfall events?

Andrew used Pocket Earth (screenshot pictured right) to record his walk with Keith down the swamp towards the national park boundary (marked as the green line near the top of the map). The black dot marked the area of major slumping shown in the photos below. The blue dot marked where the bushcare group began removing the Himalayan Honeysuckle.

We treated the Himalayan Honeysuckle at the top of the valley, but after a few hours of work there was hardly anything to show for our labours.

Before ‘cutting and painting’ the honeysuckle, you need to remove the flowers and seeds and bag them to avoid leaving behind any potential for reseeding.

Pip has cleared all the Himalayan honeysuckle from this area on the edge of the swamp.

We will need to keep returning to properly deal with the honeysuckle.

Diverted to Bonnie Doon

The Narrow Neck road remained off-limits (there was a second landslide in recent weeks and the gravel road remained closed to pedestrians and cars) so on the advice of our council Bushcare officer, we decided to control weeds in a large patch of bush where Narrow Neck Rd meets Bathurst Rd and the Great Western Highway.

The area in the map below shows our site for Saturday 6 August 2022. Access is from the truck rest area and turning bay on the left as you leave Katoomba on the way to Lithgow.

This month’s weeding site (area marked red) was a plume of holly adjacent to the Great Western Highway in the upper catchment of Magalong Creek, above Bonnie Doon Falls. Map: Google Maps.

This site is in the upper reaches of Megalong Creek. Just south side of the highway there was a large plume of mature holly trees that had been partially treated over a year ago. Our job was to remove the remaining holly.

Keith amongst the holly copse. The wavy stem in the centre is a banksia that would have been overgrown by the holly if they were left untreated.

There were some small stems of holly about a finger thickness that could be cut and painted with glyphosate, or scraped and painted (depending on which bush regeneration expert you wished to follow). However there were at least 20 larger stems that were too big to be cut and instead needed to be drilled.

A hole is drilled into the stem close to the ground, ringing the stem at intervals of about 1.5 cm.
Applying the glyphosate into the hole, shortly after drilling to maximise the effect (within about 10 seconds is ideal).

Drilling is highly effective at killing large exotic weed trees like holly and privet. There is no need to cut down the tree and it will die with a few months.

We saw evidence of previous drilling of the holly stands a year or more ago. All holly treated using this method were well and truly dead!

The drill holes in the base of the now dead holly where glyphosate was applied.
The dead copse of holly from the previous drilling operation.

We managed to treat almost all the holly before our time was over. There was one small untreated stand of holly on the south side of the site that we can treat when we return in a few month’s time to monitor the work we had done.

We also removed many small privet and holly seedlings. We will have to scour the site next time for those we missed.

It was a fulfilling morning, eliminating almost all of the holly on the site. But we were told there is a much large area of holly further downstream towards Stuart Road. We will review where we go next month as the group was keen to look for woody weeds closer to our home base at Narrow Neck.

Don’t forget, you are welcome to join our group. We meet at 9am on the first Saturday of each month (except if its raining).

Rain and landslides

The first few months of 2022 saw rain, rain and more rain. The weeds were growing faster than we could treat them, and then on 6 March part of the road to Narrow Neck (Glenraphael Drive) washed away.

Vehicle access to Glenraphael Drive from Cliff Drive is now closed due to the March 2022 landslide. Photo: Narrow neck bush care
The start of the road to Narrow Neck, where it leaves the paved Cliff Drive. Photo: Narrow neck bush care

The landslide occurred just inside the national park boundary, about 400m from Cliff Drive. Access to all vehicle and foot traffic was closed by the council and NPWS. Given the size and location of the landslide, it may be many months or more before the road is opened again. This will give a heavily used area some much needed rest.

A remarkable photo of the landslide taken from above, March 2022. The full width of Glenraphael Drive has washed away. Photo: James Young

Our bush care group no longer had access to the main access road that ran through the centre of our site. This was a chance to treat the northern perimeter of our site along Cliff Drive.

The Cliff Drive road verge has a strip of exotic grasses, which we won’t bother treating, then mostly native vegetation further in. We will look to remove or treat all exotic plants in this zone.

On our monthly sessions in April, May and June we have been treating small outbreaks of woody weeds along the bushland bordering Cliff Drive such as cotoneaster, blackberry and broom, and grassy weeds such as Parramatta grass and kikuyu.

Karen treating a patch of kikuyu.

This patch of kikuyu next to the road probably originated from illegally dumped grass clippings.

It was a tedious job but thankfully it was not a large patch.

Our treatment involved cutting each stem then quickly dropping a dab of glyphosate on each cut stem within a few seconds.

Cutting the kikuyu stem with secateurs.
Applying the glyphosate to each stem. The red spots are stems that are already treated.

And we were delighted to find a flowering Greenwood orchid.

A nice surprise! A greenhood orchid in front of the trowel.

Taking stock

It was cold – winter is when weed growth slows down and its time for the beanie – so in June 2021 the group decided to do a stocktake of our weeding site.

We walked the main roads through our site: the first part of the gravel road along Narrow Neck Peninsular, which is called Glenraphael Drive, and Cliff Drive to Narrow Neck Lookout. Up until this time we had just focused our weeding efforts on the known worst locations and had not had a good look for other weed infestations across the whole site. Karen our trusty supervisor recorded significant features and weed infestations on her clipboard.

Karen logs weeds along Cliff Drive which were treated at the same time.
Karen logs weed locations along Cliff Drive and if the infestation was small enough Paul and the rest of the team immediately treated them.

We used a smart phone to record the location of points and to confirm the location of Glenraphael Road. Andrew uses Pocket Earth Pro, an easy to use map app for iPhones. You can see the start of the route walked by the blue line.

Map of Bushcare and Glenraphael Drive site using Pocket Earth Pro.
Map of the bushcare site made using Pocket Earth Pro, an iPhone app. The blue line is the logged route of Glenraphael Drive. The dashed red line is the operational area of the Narrow Neck Bushcare group. The area to the west is part of Blue Mountains National Park.

The collected point and line data is then passed onto the Council’s GIS team.

Data collection didn’t take all morning, so while we were at Cliff Drive near Narrow Neck Lookout we got to work with those weeds that were in sight.

Judy and Pip attack a small New Zealand flax nestled in the bracken ferns near Cliff Drive.

Paul and Andrew found a large New Zealand flax plant (Phormium tenax) on the fuel reduced zone on council land close to Cliff Drive. It is invasive in forests and woodlands, so worth removing before spreading into the nearby intact bushland.

Paul is about to launch an attack.
Victory! Paul and Andrew make sure the New Zealand flax is gone after about 10 minutes’ work.

It is immensely satisfying to remove such a large weed in a short amount of time.

The glyphosate treated base of the New Zealand flax worked on by Paul and Andrew in the photos above. The red areas are the stems where glyphosate was applied, the red dying making it easier to see which areas you have treated.
After his head and shoulders were buried in the New Zealand flax, Andrew found a huntsman spider on his shoulder.

Just after this June session, the Narrow Neck Bushcare group went into hibernation as the whole of Greater Sydney was put into COVID lockdown for three and a half months. We are itching to get back into the bush and see what weeds have popped up and how much those weeds we haven’t got to yet have grown.

This is a long-game and we can wait until we are ready because the weeds are not going anywhere – well at least if they are not seeding!

Blackberry attack

March was Blackberry month.

While visiting Sydneysiders flocked to see the last of the waning Pink Flannel Flowers along Narrow Neck, the Narrow Neck Bushcare group had other priorities in mind.

With the growing season rapidly coming to an end, it was important to treat a large patch of Blackberry on the roadside before winter arrived.

Pip and Lyndal attacking a patch of blackberry near Cliff Drive and the start of Glenraphael Drive.
Pip and Lyndal attacking a patch of blackberry near Cliff Drive and the start of Glenraphael Drive.

We trimmed the long Blackberry canes to allow easier access and removed and carefully placed any berries in our weed seed bags. Then we could begin the scraping of the stem followed by a quick application of glyphosate.

Lyndal scraping and applying glyphosate to blackberry near Cliff Drive and the start of Glenraphael Drive.
Lyndal scraping and applying glyphosate to blackberry near Cliff Drive and the start of Glenraphael Drive.
James scraping and applying glyphosate to blackberry near Cliff Drive and the start of Glenraphael Drive.
James scraping and applying glyphosate to blackberry near Cliff Drive and the start of Glenraphael Drive.

The Blackberry was just at the start of Glenraphael Drive and within chatting distance of the National Parks and Wildlife ranger stationed at the roadhead managing the foot and car traffic flocking to Flannel Flower viewing.

Next month we will finish the attack of the Blackberry before winter arrives. See you from 9am to noon on the 1st Saturday of the month!

New Narrow Neck Bushcare group

By Pip Walsh

In late 2019, before bushfires and COVID, a few mature Pampas Grasses were noted along parts of Glenraphael Drive, which is off Cliff Drive at Narrow Neck, Katoomba.

The sighting was flagged with a friend, who suggested we start up a new Bushcare Group.

As part of our investigation, we realised that we had several small drainage lines where various weeds were flourishing and if we tackled them, we could help protect the Escarpment Complex vegetation and a population of the threatened species Pherosphaera fitzgeraldii (formerly known as Microstrobus fitzgeraldii).

The team at their favourite morning tea spot overlooking Jamison Valley
The team at their favourite morning tea spot overlooking Jamison Valley. L to r: Pip, Lyndal, Andrew, James, Judy and Paul. Photo: BMCC.

Pampas Grass has become a dim memory, and has now been overtaken by our dedicated Holly hunting, as well as a bit of Privet, Cotoneaster, Himalayan Honeysuckle and Ivy hunting for variety. At some stage, we will have to tackle the Montbretia.

Bushcare veterans realise we have years of entertainment ahead. We do have a fair bit of manoeuvring through the bush to get to our weedy targets, but the effort is made worthwhile when we break for morning tea and look out over the valley below and across the southern mountains.

We now have a regular, core team, but since formally becoming part of the Bushcare Program from November 2020, we would be pleased to welcome more members.

We meet on the first Saturday morning of the month.

Contact Pip Walsh pipwalsh (at) ozemail.com.au or Karen Hising (BMCC Bushcare Officer) khising (at) bmcc.nsw.gov.au