The foliage and stems of my
Allium sphaerocephalon are
going yellow and are covered in brown spots. They aren't yet quite in flower but the buds are appearing and don't seem to be affected. Can anyone tell me the cause? Thanks.
That looks like a bad case of rust, Kephigoo. It's a fungal disease. If just a leaf or two is affected, you can remove them to prevent it spreading - but I fear your alliums are too far gone, sadly...
Since 2019 I've lived in east Clare, in the west of Ireland.
Thanks. So should I dig them up and destroy them, just remove the stems or leave them and hope they'll be OK next year? I've got Purple Sensation Alliums nearby that haven't been affected and have now finished flowering - I don't want it to spread to them.
Get those stems out asap and burn them. Then hope that the rust does not spread. Sadly it often does. I have just dug up over a 1,000 of various types of dwarf Alliums because they are so badly rusted. We can no longer grow culinary onions or leeks because of it.