Mulching and feeding
Just as the first flush of flowers fades, remove ƒdead heads and if the soil is dry, give plants a thorough watering under the foliage to the roots.
Remove any weeds and apply a second dose of rose fertiliser (hopefully they received one in late winter as well). Organic rose fertiliser is available.
Spread a mulch of well-rotted compost over the roots but away from the stems, to help hold in the moisture and feed the soil.
Good care will enable regrowth despite black spot. Yet do gather up fallen rose leaves and dispose of them away from the garden.