Monday, June 6, 2011

Winter Weeding

I've survived three days of weeding and am grateful for the long weekend. Working fulltime is a bit of a shock but I must be fitter than I thought as my body's not complaining too much! The Weed Team's mission is to search and destroy Darwin's Barberry which was brought to the island as a hedging plant some time back. Not happy with escaping from the garden, it is now growing in native bush and doing very well. Most non-natives can't grow in low-light areas but Darwin's Barberry thrives in our cool, dark bush and grows quicker than native seedlings, thus crowding them out. The plan is to eradicate it from the island - it would have been so much easier (and cheaper) to have stopped it coming here in the first place.

Darwin's Barberry on my property
The area that we are working on used to be farmland; it's now regenerating scrub/bush with lots of gorse, barberry, blackberry and bracken. It's demoralising to see so many barberry plants - it's not an easy plant to get rid of and cut stumps and branches will shoot/root again without difficulty. We've found a number of 'adult' (over 1500mm tall) and 'huge' plants (stem diameter > 150mm at chest height) and unfortunately birds feast on the berries with widespread dispersal of the seed so plants are scattered throughout. Growth appears to be rapid although research carried out in Wellington showed that seedlings have a high mortality rate but I haven't seen evidence of that down here!!

The members of the Weed Team line up a few metres apart and, using GPS and compass, walk/crawl/climb boundary to boundary. On finding barberry, you shout out 'Barberry' and set to work cutting or pulling the plants out, coating the stems with Vigilant gel. A waypoint is then marked on the GPS unit with a count/estimate of adult, juvenile and seedling plants. Once the team reaches the boundary, you move along a bit and do another line parallel to the first. It's been slow going in this high-density area but no doubt it will go a lot quicker when we move into older, more established bush.

We're also on the lookout for other nasty weeds - Chilean Gunnera is another garden escapee that is costing a lot of money to control. I had several plants here - some biggies with leaves over a metre in length. Again, the birds eat the fruit and disperse the seeds, often in hard-to-access areas - like the middle of blackberry patches!! The South Taranaki coastline has a big problem with Gunnera infestation needing helicopters to access the cliffs so that they could spray it.

A small Chilean Gunnera seedling
I wish we could turn back the clock and ban imports of non-native plants. I don't think anyone will make the mistake of introducing predators like stoats again but plants are being brought in all the time, with expensive control measures required to control them in the future. The Native Plants course that I did in 2005 opened my eyes to the ecological damage that happens from garden escapees (Old Man's Beard, gorse, ragwort, broom, heather, mexican daisy, horsetail, wandering jew...) and I decided that I would no longer plant non-natives and since moving down here, I will try to stick to plants that are native to Rakiura - with maybe some extension for natives that are on the endangered list.

I have my work cut out as I have a lot of gorse, blackberry and broom on my section but I guess it's just a matter of keep plugging away and removing every weed plant when it appears. You can help too by thinking carefully about the plants you choose for your garden. Regional copies of 'Plant Me Instead' can be downloaded from the Weedbusters website here: http://www.weedbusters.co.nz/get_involved/plant_me_instead.asp