Galinsoga Parviflora?

[Chantal]

A long, long time ago I asked if anyone knew how to eradicate Galinsoga Parviflora but the consensus on here was that the weed we have on our site isn't that at all. I've finally managed to get a photo of the horrible stuff



and I'm certain that's what it is. It grew this high



in just 2 weeks. I throws down seeds and also runs underground.

Ideas anyone?

[oldherbaceous]

Dear Chantal, it looks like Gallant soldier to me, if you can keep clearing it, the seeds should stop appearing after about four years.
Or maybe black polythene sheeting for a season, then keep hoeing.
Maybe Jenny could recommend a really strong nasty spray for it.

[Chantal]

Thanks OH, Gallant Soldier is the common name of Galinsoga Parviflora. If it was on my plot it would be gone everytime it stuck it's head through the soil. The problem is that it's on four other plots and they're not weeded sufficiently to keep it down. It's spreading every year. Unless we take back the plots, spray it with glyphosate and then put down black polythene for a couple of years we're stuck with it. Unless anyone knows better.

[Jenny Green]

Such a shame, it looks quite pretty!
This is about the only thing I disliked about having an allotment - no matter how hard you try to eradicate a weed on your own plot, there's always someone else cultivating it on theirs!
This is the main reason I gave mine up. If you can't keep on top of it, you should let someone else have a go, out of fairness to other plot holders.
The only methods I can recommend are contstant hoeing (not so easy in this weather!) or black plastic, though I think one year would be sufficient to kill the roots. Then maybe a flamethrower to burn off the seeds?
Sorry not to be of much help. The proper solution is to get other plotholders to be more considerate of others.
Oh, and Herby, the only strong spray I know of eradicates pernicious HERBACIOUS nuisances.

[Chantal]

Thanks Jenny, this is easier said than done. One person does weed on an almost daily basis but if he goes away for just a week his plot is covered by the time he comes back. It's a full time job just weeding and hoeing this stuff without even thinking of doing anything else on the plot. It's the stuff of nightmares; talking of mares, it arrived on the site in a stack of manure.

[oldherbaceous]

Dear Chantal, sounds as if you need some divine intervention, at least it might take your mind of the weeds.

[Johnboy]

Hi Chantal,
I rather suspect that the weed is Shaggy Soldier (Galinsoga cilata) which is obviously very closely related to G. parviflora. Both originate from South America and they both have become naturalised and are more common in the South East. I wouldn't actually put Rugby in the south east but I suppose over the years it has become more widespread.
I say Shaggy Soldier because of the leaves. On the cilata they are quite a large broad leaf and on parviflora they are narrow leaves. I suppose it doesn't make a jot of difference it will still be a pain in the *****.
Looks to me as though it would make good compost if cut continually that may be one way to get rid of it.
If you manage to allow it not to seed then it will not spread as both varieties are annuals.
If you could catch it before it heads up to flower
you may have residual seeds in the ground to cope with for a couple of years but if you keep cutting it before heading up and I am sure it will disappear.
JB.

[Chantal]

Thanks JB, I'm not sure if that is good news or not!

Composting the hateful stuff is not really an option as it flowers almost before the leaves grow. The seeds seem to resist any compost heaps and just start growing again when the compost is used.

The guy who's almost (!) on top of this keeps pulling up a binliner full a day, but he's been doing this every summer/autumn for the past 3 years. He's also hoed and sprayed but if he leaves his plot for a week or two it's still as bad as ever.

The only good thing about it is that it does pull up very easily. The bad thing is that it leaves little roots in the soil which become new plants before you can blink.

We are truly concerned that it will eventually take over the site. I make people from the affected area wipe their feet and check their shoes for mud before allowing them on to my plot. I won't borrow their tools or lend them mine and yes, I am paranoid. However, one bloke had two plots, one at each end of the site, and there is now weeds on both plots, clear indication that he spread it around.

[Jenny Green]

Sounds like an absolute nightmare.

[Johnboy]

Hi Chantal,
It would appear that digging it leaves french cuttings so the best thing is to simply cut it down if you can't compost it, which seems very wise under the circumstances, then put it into black bin bags and store for a few months then have a mammoth bonfire at the end of the season. After the last cut cover with black polythene and leave it until next Spring at least and a lot longer if possible.
Hi Jenny,
I still think that this is not as bad a Perennial Sow Thistle!! That took me 15 years to get rid of.
Remember all your sterling work only to give up your allotment. Such a shame.
JB.

[Jenny Green]

I was just stretching myself too thin JB. I might have killed off the Sow Thistle but other things in other areas were getting out of control, so it was time to move on.
The person who has it now does a great job and I'm just happy I made his life a little easier.
No doubt I'll get another in a few years when Conrad's no longer interested in me!

[Chantal]

Thanks JB, I'll make your suggestion.