By Claretsfan
United Kingdom 
I have noticed that my roses are suffering badly from black spot... except the one growing next to a rosemary bush. Given that rosemary has medicinal qualities for people, is there any evidence that it could be used to counteract plant diseases too?
Thanks
Pat Hulme
12 Aug, 2011
No idea, maybe you've found a preventative, lol. In reality, some varieties of rose are much more prone to blackspot than others - plants of this type need regular spraying during summer to keep it at bay.
12 Aug, 2011