[Jaybeecee]

Hello everyone, I'd like some advice on what to do about 2 acres of our pasture.

We usually pull any ragwort we find, but this year the back 2 acres of the land exploded with Oxford ragwort and there was way too much to pull. The land to the side of us was empty for a while and was full of ragwort 2 yrs ago and it's seeded in our paddock. Last year's drought and the 6 weeks of solid rain late spring has really taken its toll on the land and its in need of tlc.

We treated it with Grazon Pro and the ragwort flowers and leaves are wilting nicely, but the woody stems are still upright. We'd like to top and overseed the problem areas before the weather turns, but I'm a bit concerned about how this may affect the efficacy of the Grazon treatment.

Is there a point at which the Grazon has done its job and stops working regardless of topping, or will topping in a fortnight's time stop the Grazon from continuing to treat the roots of the ragwort?

I'm hopeful we can use some of the 2 acres over winter to take the pressure off the rest of the land being poached to oblivion (we're on clay land which is productive but heavy going in winter), so I don't really have the luxury of leaving it until next spring.

[Forestlens]

The problem will be that the ragwort “straw” is the poisonous bit. What are you planning to do with the paddock? Grazing it with high levels of dead or dying ragwort won’t be an option. Please read the Grazon Pro label as it gives warnings about crop residue management. https://www.corteva.co.uk/content/dam/dpagco/corteva/eu/gb/en/files/labels/Grazon-Pro-label.pdf

[Jaybeecee]

Thanks. We wouldn't need to use the 2 acres until late winter, so there's plenty of time for the stems to decay, particularly if we top them with a topper that mulches. But I don't want to do that if the Grazon continues working for weeks after application to kill the ragwort roots off.

I've looked at the information for Grazon and although it states the land must be left until the ragwort has dissolved/decayed, it's silent on when topping can be done.

Ideally we'd like to top the whole 2 acres in a couple of weeks to get rid of the other, harmless weeds and harrow/overseed in the autumn, then treat the area again next spring to catch the rosettes. But as I stated, I don't want to mulch the ragwort stems if it affects the efficacy of the Grazon Pro. My concern is whether the Grazon continues to work for weeks after application and the topping would be detrimental to this. It might be the case that by then the stems have rotted anyway, but it's too early for me to tell.

Being clay land, the window of opportunity is quite narrow as it soon becomes too wet to do anything with once the winter sets in.

[Forestlens]

Hi Jaybeecee, after 14-21 days I would have expected the Grazon Pro to have done all that it will do, so topping won’t have any detrimental effect on its performance.

[Jaybeecee]

Thanks. I thought that might be the case, but wanted to check. I couldn't imagine it would continue working after a few weeks, but as it's such an expensive product to use, I didn't want to run the risk of topping too soon.

By the time we get round to topping it'll be at least 5 weeks after treatment & most likely 6 or 7 weeks depending on the weather.