Black spot is the scourge of every rose grower. Most roses at some point will be hit with the disease, which as the name suggests, causes black spots on foliage. This is often soon followed by a yellowing and premature drop of infected leaves. Black scabs can also develop on stems, all combining to prevent healthy growth.
The evolving nature of the disease means that even new resistant rose varieties will eventually be hit by a new strain that they won’t be able to fend off.
To prevent spread, fallen leaves should be removed from the garden and ideally burnt. However, the spores can be carried to any garden on the wind, and aphids too (another common rose problem) can carry the disease plant to plant.
So, to prevent the risk of black spot taking hold on your garden roses, a preventative systemic spray such as Rose Rescue Ready-to-Use should be used at intervals through the growing season. Start this with an application to emerging new growth in spring. Repeat this after the first flush of summer flowers have been removed from the plant. For total control, cover all foliage parts thoroughly, including the underside of the leaf.