You can't get rid of it completely - some roses are more resistant than others, so buying the more resistant ones helps, but roses are high maintenance plants - to keep them healthy, they need to be sprayed between April and September fortnightly, using a systemic product such as Roseclear 3, which treats for both fungal infections and aphids. Feeding twice a year with a specialist rose feed is a good idea too, this will help them resist infection better. Good pruning practice is esential too - keeping the bushes open to airflow also helps. Clear away all fallen leaves which are infected with black spot immediately they fall. Where black spot is a problem, underplanting isn't advisable - bare ground beneath, with maybe a little low edging, is best, with nothing growing directly beneath the roses.

A good mulch after clearing away the old fallen leaves will help suppress the black spot spores that are in the soil. Bring back smog, as this kept it at bay!!

Thank you both.