Planted six rose bushes (bought from a good garden centre) last summer. The stems are now covered in an overabundance of thorns. Some are thick and red , mixed
with thinner spikier brown ones. Can hardly see the stems! ! Also red witches broom type growth sprouting all down stems. Some very thick malformed stems .
Web research indicates that this is rose rosette disease ....seems to be quite prevalent across America ...recently. ..having made the leap from fairly wild multiflora type roses iin parks and on roadsides to cultivated roses in gardens.
There is loads of information on USA websites. ( sorry can't do links) but no UK references. The photos on US sites look exactly like mine..(sorry can't post photos)
Neighbours garden has a very old briar type rose which looks to have the same
problem. We live about 70 metres from the sea in NW England ...could this disease have travelled on the wind across the Atlantic! !