A mouldy nuisance on your roses

Rosa Complicata.
Rosa Complicata.

Two common leaf problems, black spot and mildew, are already testing the patience of local growers and it’s a case of prevention being better than cure.

Any spraying has to begin at bud-break in springtime and continue at regular intervals throughout the growing season. When these diseases appear in the absence of a spraying programme, the best we can hope for is containing them.

My early gardening life demanded a knowledge and use of pesticides and insecticides, but once free from that burden, other options could be contemplated. Hence the organic stance in this garden.

It is possible to tolerate a certain amount of black spot on rose leaves, the worst of which can be removed and disposed of. If mildew covers a favourite variety, prune away the worst-affected parts without calling a complete halt to the overall display. For example, a group planting of the apothecary rose (rosa gallica officinalis) develops mildew later in summer, but we have a few weeks of unblemished display.

Similarly, a climbing New Dawn against the dry house wall has to be mulched to keep the grey menace at bay as long as possible.

But the positives in growing roses far outweigh any puny diseases. Stand over a David Austin English rose such as Gertrude Jekyll in full bloom, and give the olfactory centre a treat. All of their fragrances are absolutely stunning right now.