“A good herbicide is a key component of any gorse control strategy, so if you want the job done properly you should be prepared to pay a little extra for the right product.”

That’s the philosophy of farmer Allan Smith who has spent several years battling gorse on 100 hectares of leased land in northern King Country.

“I reckon you should do your sums on what’s in the herbicide and not on the price on the front of the drum. It’s the ingredients and what they will kill that really decides the product’s true value.”

Allan and wife Sonia run a 250-cow dairy farm at Whawharua, south east of Otorohanga, along with a nearby lease block that is used for dairy replacements and beef cattle.

In recent years they have put considerable time and effort into developing the lease block through fencing and gorse control.

Allan says gorse was a big problem on the property and he estimates that over 40 hectares were affected to some degree. Aside from a 10 hectare area of dense gorse, most of it was scattered around in patches. Many plants stood over 5 metres high.

Ragwort was also a significant problem, with Allan describing the place as “a sea of yellow”.

“The first thing I did was go in with the digger and push the Old Man Gorse over. Then we’ve used chemical (applied by helicopter and groundspraying) to control the rest.”

Allan says he originally made the mistake of going for cheaper chemical to save money. It didn’t. The kill rate was far less than expected. Most of the sprayed plants appeared to have died but later started regrowing.

Three years ago he switched to Tordon Brushkiller. “Once I saw the results Tordon gave us, there was no looking back. You hit a plant with Tordon and it dies quickly and breaks down fast.”

Allan says that almost 38 hectares have been cleared of gorse and are now growing good pasture. “The place is a huge improvement on what it was. We’ve doubled the grass growth and doubled the stocking rate. Last year we wintered 230 head of cattle. In the first year we only ran 110.”

Other weeds are also under control. “One of the best things about Tordon Brushkiller is that it also kills weeds like blackberry, ragwort and thistles. So you can spray those weeds as you go past on your way to the next gorse plant. It effectively makes weed spraying a one-pass job and saves on labour.”

A lot of the gorse spraying work is carried out in spring when other weed seedlings are germinating.

“It doesn’t seem to matter what time of year we use Tordon, it always gives us a good kill. We do quite a bit of spraying in winter and being able to spray in cooler temperatures is a significant advantage because it means we can fully utilise our labour force during what is usually a quieter time of the year.”

Allan say Tordon Brushkiller is the most effective herbicide he has used.

“It’s a great product and I will definitely continue to use it in future.”