10 thorny rose problems and how to avoid them

Get the best from your roses this summer by identifying these 10 issues, and nipping them in the bud. By Tom Brown

Roses are considered to be Britain’s favourite flowers. Part of their appeal is the romanticised, evocative feeling of a warm summer’s evening in a English garden, surrounded by the heady scent of blooms. The reality of how some of our roses perform in the garden, however, can bring us crashing back down to earth. It can make us question what we might have done wrong, particularly if we are dealing with one or two troublesome disorders, diseases or pests.

As with many common gardening problems, the key is in prevention, rather than trying to find a silver bullet or a chemical-based cure. Roses are hungry and thirsty plants, so by giving them a little of what they need and selecting the right rose for your garden, there’s no reason why we can’t all enjoy a little rose-based fantasy.

Here are 10 of the most common rose issues, and how to avoid them in your garden.

1 Aphids

One of the most common, colourful and prevalent rose pests in our gardens, these insects are likely to congregate on the soft, young growth. They will feed on sap and cause a reduction in vigour, as well as potentially transmitting viruses.

SYMPTOMS

Growth may become distorted and weak, with some flower buds failing to open. A sugary substance, known as honeydew, can be exuded by aphids, leading to a secondary infection of sooty mould.

SOLUTIONS AND PREVENTIONS Aphids are preyed upon by several other insects and birds, forming part of a wider ecosystem. Early infestations can soon be reduced when predators such as ladybirds emerge a little later. SB Plant Invigorator can be applied, which stimulates growth, controlling aphid numbers if applied regularly, and as prevention from first signs of growth.

To help keep aphid numbers under control, encourage predators – for example, by installing a bird box close to your roses.

2 Black spot

Black spots appear on the surface of leaves, which then turn yellow. This fungal disease, which is particularly associated with stress, often appears in summer. In more extreme cases, it results in dieback and severe defoliation.

SYMPTOMS

Purple or black spots appear on the leaves, causing a lack of vigour and premature leaf drop.

SOLUTIONS AND PREVENTIONS Collect affected leaves and do not add to your compost heap: either burn them or add them to your household waste. Hybrid teas, floribunda and patio roses can be more susceptible. To avoid this disease, plant disease-resistant, modern varieties or more robust species roses.

3 Powdery mildew

White, powdery fungal growth colonises on the leaf surface. This widespread disease often afflicts roses during summer and at times of water stress.