On Wed, 28 May 2014 13:07:05 +0100, Martin Brown wrote:

On 28/05/2014 12:46, Nick Maclaren wrote:
In article ,
Emery Davis wrote:
On Wed, 28 May 2014 11:27:10 +0100, Martin Brown wrote:

I mean regular hogweed, not the giant variety thank goodness.

That's not a major problem, despite the tabloid hysteria. Yes, it's a
thug.

It's pretty invasive. There's now enough of it in the area that it will
probably be impossible to eliminate entirely.


It should be good enough to hit it with any broadleaf specific
herbicide assuming it is in grass or glyphosate if you don't mind a
bit of collateral damage and scythe it down in flower before it sets
seed.

I haven't found glyphosate to be effective, possibly I've been a
little late in the season. Do you have a particular boradleaf
herbicide to recommend? (If it kills dock and too, that would be just
fine...)

The normal problem with using glyphosate is following the instructions
on the bottle :-(

I agree, but it is in the manufacturers best interests for people to use
more of the concentrate than is needed for optimum kill. You have to
wait a bit longer for the weeds to die but it gives the glyphosate more
time to translocate around the root system on pernicious weeds.


I know how to use it. But the weather is not always propitious, and I'm
not always here. So sometimes it is catch as catch can.

They sell a fast acting prediluted "Roundup" that contains something
else that kills the weeds before the glyphosate has time to act! Selling
impure water has very high profit margin (windscreen wash too).

True. I buy it from the ag coop. There may be a cheaper place but
not so much so that it's worth putting the time in to find.

[]
It is easier to spot any green regrowth or weed seedlings against a
charred black background.

I don't think burning the fields to spot new hogweed growth is a solution
that fits the size of the problem. But it is easy to see when it comes
into any mulched areas.


Glyphosate is actually grass-specific, and will kill grass at levels
that leave most other plants alive. The only one more effective that I
know of is brushwood killer - but even that doesn't kill established
trees and shrubs in one go.


Glyphosate wont kill shrubs outright, but it certainly does knock
Japanese maples back, and weakens them so that they're much more
vulnerable to verticillium. But, it won't kill even sycamore seedlings...

The one thing apart from waxy plants I find it ineffective against is
buttercup. I have killed some larger areas with glyphosate and always
noticed that afterwards the buttercup is quickly back in business.

I agree completely: glyphosate is not very effective against buttercup.
Sadly. Or, for that matter, yarrow.

-E

--
Gardening in Lower Normandy