I've been documenting our progress with eliminating blackberries from our top olive paddock for awhile now.

Recently we had a breakthrough, and I am confident we will be looking at an almost clear paddock next year. Its funny, I was so close to almost getting it....but I was still missing the punchline.
Let me backtrack.

Landcare ran a blackberry field day a couple of weeks back. They had a site out in King Valley, along the river, heavily infested with blackberries. You know....two metres high, the patch starts 30 metres from the water and goes all the way into the flow of the river.

They marked five or six spots, then applied different herbicide treatments to each section. The field day was a tour of the sections, and information sheets on what sprays had been used. It was delivered by Gary, who co-incidentally, was the bloke who dealt with the blackberries along the river at our place a couple of weeks ago.

One of the things I have said on this blog awhile ago was that mowing blackberries as a strategy wasn't working...all we were doing was naturally selecting plants that grow along the ground. And another issue I had was that sometimes I would spray an area, and some plants would show no sign of the herbicide. One reason for that is simply me missing an area or plant. This year I found two thriving clumps of blackberries, both in a long straight line. Clearly I had sprayed in that area, but the line I took missed a section.

But that didn't explain it all. There's a clump that I see all the time and I know I sprayed it. No sigh of wear and tear.

And while Gary was talking the light bulb exploded.

There is more than one variety of blackberry plant. (14, actually). Yes, we have some blackberries that grow along the ground. Yes, sometimes those blackberries shrug off the metsulfuron spray that I am delivering. Because they are a DIFFFERENT BLACKBERRY!

They look different. They are different. They react differently. I had the clues but I don't think I would have worked it out by myself, but as soon as I understood it the clicking of information slotting into place was deafening!

A few days after the field day I tackled my nemesis blackberry plants with a slightly different recipe. Its working. They wilted overnight, and they are quickly browning at the edges and spotting up. I am certain they are going to take a hiding.

Interesting comment number two related to volumes and recipes. Gary, as an aside, mentioned that like some cooking recipes, you sometimes need to adjust volumes if you are doing a smaller mix. That is, the product information gives you mix recipes assuming a large volume of spray. Typically 1000 litres. Most the time I do a 50 litre mix. Gary's point was that if you are doing a smaller mix you need to increase the volume percentage of the active ingredients....a stronger mix. I didn't know that. I do now, and I have recalibrated accordingly.

Interesting comment number three: Gary gets called out to, say, a dairy farm to deal with blackberries popping up in pasture. Easily done, but its a regular job for him. "Why don't you let me tackle the gully..?" Gary askes the dairy farmer. "Nah, its all fenced off from the cattle. We don't use it." But that's where all the seedlings come from.....This isn't an issue for us with blackberries, as we are trying to remove them in general. But Privet....we had paid Gary just recently to spray a lot of privet seedlings along the river. But the mature, adult Privet trees are still there, and there are two near the house. Its obvious that if we don't get rid of them we will continue to have to deal with new seedlings. SO obvious!

Anyway, its late in the season, but I have been giving the blackberries a serious go. There's a couple of spots I missed. For example, we are heavily pruning olive trees, and I know there are some clumps of juvenile blackberries under some of this prunings. We won't get them this year. But next year we are hunting escapees, and one-offs. The saturation coverage per square metre is a thing of the past. Some rows in the olive grove have no blackberries.

We are nearly there!

What does this photo show you?
Firstly, it shows a strip of blackberries far thicker and bigger than anything around it. This is an area I missed last year. Driving up and down, it usually takes three goes to cover a row between trees, Sometimes I get distracted or mixed up, and I simply missed this section completely.
Look at the area to the left and the right of the blackberries. Almost clear. Not that long ago the entire paddock was as thickly covered as this row. The cluster of blackberries are now the exception.

This remnant row has been sprayed just recently...a couple of weeks ago. It is showing that it is dying. Not 100%...there's a couple of green sprigs on the edge, either new growth, a rooted runner, or simply missed yet again.
Conveniently, our cattle crush the brittle dead canes underfoot, so by next year only the green canes will remain. But then they will be small islands of blackberries to spot and collect, not an entire continent.