More on ragwort from our correspondent in Gloucestershire
"It is the Oxford Ragwort which leaves root fragments very easily if you try and pull it. This plant has multiple, and more easlily broken, stems and more feathery leaves than the "British" ragwort, which tends to have only one or a few stems, and pulls out just fine.
We pull both kinds every year on our 365 acres (taking great care to get the Oxford roots as well as their stems), and it diminishes every year in the areas where it has been allowed to become a bit established. The claim that pulling (actually pulling it, not leaving the root) increases it 4 or 5-fold is complete rubbish! Utter, utter rubbish. But that will probably now become yet another myth believed across the land.
Instead of spreading this new myth, the researchers should be advising all concerned to be sure to pull all the roots, which is often not easy, and sometimes requires deep cutting below ground level.
And if we followed dear Prof. Crawley's "research" and let it seed.....
That may kill the original plant, but where does he/she think we get the plants from every year in the first place?
We've had yet another glimpse into the wonderful world of cloudcuckooland.
It's interesting that the Ragwort Facts website where the research is quoted, doesn't even manage to spell correctly the species name of what I rather jokingly called "British" ragwort. They have Senecio jacobeae instead of jacobaea.
More one-sided misinformation. At the end of Ragwort Facts 'Ragwort Dispersal' page it is stated: "The simple and fundamental truth of the matter is that ragwort seeds while capable of dispersal over great distances only do so under very rare and unusual circumstances. Consequently ragwort growing on roadside verges where is it of great ecological value to biodiversity does not usually need to be controlled".
I would say that windborne seeds being carried up to height by passing thermals in August is not a very rare or unusual circumstance, and this must be where new plants come from. (When gliding we find clumped thistle seeds thousands of feet above the ground and indeed they are a good indicator of thermals). Back on the ground here in Gloucestershire, we find that, as cited on that page, and as with the windborne seeds of biennial thistles, most colonisation from seed is very local to the parent plant. But we also find that where there is ragwort the other side of a hedge or fence, it will appear nearby on our patch. And we also find new plants springing up here and there every year from windborne seed, setting their seeds and starting colonies.
A couple of other comments on Prof. Crawley's summary: (1) he says that "mowing down" ragwort is a "method beloved of farmers". I have never heard of any farmer doing this, since we are told that it is dried ragwort which stock will eat and which can poison them. (2) referring to his last three sentences, you will always get "competition-free microsites" on any pasture, even if well-managed: one hoofprint in wet weather does it. And finally, ragwort seeds germinate well in rough ungrazed ground, of which the roadsides quoted are one example.
I have the greatest respect for Fellows of the Royal Society, but if only these academics knew a little (or maybe a lot) more about what actually happens in practice.
If the Ragwort Facts people don't want ragwort largely removed from the land, then, rather like the bTB, we are going to have to go on and on and on pulling it from every piece of pasture and rough ground year after year, in order to prevent it being cut and dried in the hay, to please people who don't have to do this. That's the actual "simple and fundamental truth". That's what actually happens on peoples' farms. Rather depressing. Ah well."