My friend Adeline, from the UK, just sent me these photos which I thought were interesting and
should be shared.
She said that "like many grassland farms, we have a creeping thistle problem. Usually we top once or twice a year to stop them seeding, but it doesn't do a lot toward stopping them coming back. This year I am seriously thinking we should leave them alone, as per photos below."
"A very sorry looking stand of thistles."
"Seems whatever is killing them is carried by black fly, which are very abundant this year."
"The black fly seem to come and go and leave them looking like this."
"I am wondering what is going on to the root system, because this one has not had black fly. Healthy one next door."
"End result. I don't want to top and get in the way of this process. Would like to bottle it for another year."
I asked her if she though it was a disease *carried* by the blackfly rather than the blackfly themselves?
"I think so, at first I thought just blackfly, but it seems to damage where there are no blackfly and also eventually neighbouring plants. It also seems to affect spear thistles, but not so much, and they don't usually get blackfly like this. It looks like maybe a septoria or even a mixed infection with rust."
Has anyone seen anything like this before? Any experiences or knowledge to share?
