Clearing the Pest Weeds and Vines

It took me two years to remove the Banana Passion fruit and Old Man’s Beard vines from the remnant native bush. I then cleared small sections along the track and planted in natives.  Mostly it was to hand slash a track around the edge of what I wanted to clear and to spray, with Roundup or Tordon, the mat of vines that covered the area that I wished to plant in natives.This was okay but one had to be aware of the wind when spraying but this method used quite a lot of spray. After the spray had worked, I hand cleared the dead vines by rolling them down the hill, into a heap to rot down.

The areas to be cleared of weeds contained; Clematis vitalba (Olds Man’s Beard), Passiflora spes. (Passionfruit vine), Ulex europaeus (gorse), Rubus fruticosus (blackberry), Crataegus monogyna (hawthorn), Berberis vulgaris (barberry), Cytisus scoparius (broom), Leycesteria formosa (Himalayan honeysuckle),  Solanum mauritianum (woolly nightshade), Silybum marianum (variegated thistle) and Rosa canina (briar or rose-hip).

Some said that I was just wasting my time and it was a big job so I needed to think!  After some mistakes, this is what I found worked best:

The first step was to look over the matt of vines smothering all that grew to spot the tips of any native tree leaves that grew above the vines. To cut and slash my way to them and then to release the tree from all the vines. The trees could then recover and grow while the area around them was gradually cleared with the weeds being rolled down hill into heaps.

With large patches of weeds I “clear-fell”  and roll back the mass of weeds but leave the roots of the pest weed (Old Man’s Beard, gorse etc.) and then spot spray these when the regrowth comes about a week or two later. This will take about 2 to 3  spray ‘runs’ to get rid of them as I usually miss some the first time around.  Sometimes the weeds and vines are so thick, I use a chainsaw to cut the vines and gradually roll them back down hill into a heap to rot down.

Spot spraying used a lot less spray too.  After the replanting the area just needs to be checked on occasions for any new weed growth. Usually grasses, and recently, fleabane, grew and this required clearing around the native plants, especially during the summer with a scrub-cutter or spot spraying.  After two years or so, the natives had grown enough to crowd out any weeds and after that it only required about three to four checks each year to keep weed free.

To fell or not. Should one cut down the likes of larger hawthorn, barberry and gorse trees? At first I just ring barked them and sprayed the Tordon diesel mix on the exposed cuts. They died but much later they fell down and caused damage to native plantings.

Since then, I’ve found it best to cut them down straight away. Sure they will do damage but at least it’s controlled and over with. I like to cut up the fallen tree as much as possible, especially branches, with the idea being to get most of the tree onto the bush floor if I couldn’t make a heap nearby. Any weeds/vines that pop through the heap are easily taken care of by spraying. I like to keep the bush floor clean of debris so that it is easer to spot spray any weeds that pop up. Some have said the fallen provides a mulch but I’ve found that it just harbours and hides vine seedlings which are otherwise easy to pullout or spot spray.

To save a lot of maintenance work I’ve found that it is best to plant fast growing species; Pittisporum eugenioides (lemonwood, the fastest growing for my area), Dodonaea viscosa (ake ake), Pittosporum tenuifolium, Aristotelia serrata, (wineberry) and Leptospermum ericoides  (kanuka)  in that order and planted one metre maximum distance apart.The idea is to have fast growth to crowd out (& restrict daylight) any weeds. I like to use greensleeves (spray guards) with one stake when planting. This helps find the plants if the weeds get too high. Once the plants grow two metres or more in height, the weed maintenance work only requires periodic visits to keep under control.

Two or three years later infill planting can begin with slower growing natives; e.g.  podocarps, beech, and also with under-storey plants such as; coprosmas, psuedopanax, and the like.

The planting is the easy part, it’s the clearing before hand that takes most effort but once that is done my general approach is to get quick growing species established and once they grow up to about two metres high, it is a lot easier to control the weeds.

Patrols (search and destroy missions!) are taken every so often through the bush and newly planted, targeting new pest growth and young plants of the various weeds, spot spraying with either Roundup or Tordon.

I like to stake each plant and place a spray guard around it too. With the spray guards, I cut the plastic length in half thus cutting costs, and find them useful, not so much as a spray guard but most useful to see the plant if the weeds and grass become to long, when using the scrubcutter. Once the plants reach about one or two metres high, the spray guards are recovered and if they have to be cut off, are taken home and stapled together for use again.

The work done over the years has been useful as a living laboratory for trapping, weed control and removal and reintroducing native plants. The methods that I now use have been learnt by trial and error and I welcome any interested people to share this knowledge.  I have been surprised at the interest in this and do enjoy taking tours of the area too.