WITH hot weather, it is understandable that we need to be on the lookout for diseases that would once have been confined to the south of England.

And it is important to note that as much as we will be required to water, we need to be careful not to overdo the watering on any plants especially rose plants, which can suffer from black spot.

This disease is identified with dark patches eventually turning black as the disease progresses, leaf tissue may turn yellow around the spots and the leaf is likely to drop.

It will infect plants again in subsequent years if control methods such as removing infected leaves are not carried out. Spores can also be carried in by rain.

It is an unsightly disease and difficult to eradicate, so it's important to give your roses the best possible start. Good cultivation, adequate feeding and especially good drainage and irrigation are the best methods of avoiding problems.

Persistent attack on some varieties can leave the shrubs jaded each year and ultimately reduce them to a fraction of their true selves.

Black spot attacks the leaves, usually from mid-summer on although it lurks over winter on fallen and diseased stems, spreading to healthy new leaves in spring.

Each affected leaf that falls carries millions of spores which overwinter in the soil.

When the weather is as hot as this week, overhead irrigation with a fine spray helps to reduce the attack of black spot but this must be done in late evening. Alternatively if your plant is not showing signs of disease water the soil around the plants, being careful not to over water.

Good resistance to the disease is found in newer roses and also bush-type roses.

It is important to keep your roses well fed. High potash is important as is iron and if your soil is alkaline, consider a fertiliser containing magnesium.

There are many rose fungicides available from Everris/Scotts that are good at controlling this disease if spotted at an early stage. There are also organic based fungicides available.

If you do start a fungicide treatment make sure you continue spraying and avoid watering over the leaves.

If you do not want to go down the chemical control route, incorporate high potash fertiliser and pick off dead leaves that have been affected.