Wednesday, 2 March 2016

Problem Area - Plant Diseases ... Rose Blackspot!

Good Morning!
Plant disease is a fungal, bacterial or viral organism which interferes with the normal growth rate of plants, producing visible symptoms that reduce economic or aesthetic quality.

The focus of today's post is a Fungal Disease and these have visible symptoms such as -
Leaves producing spots, wilting & curled leaves, dieback, enlargements (galls) and stunted / dead plants. Some fungi's produce other visible signs such as rusts, mildew & sooty moulds.

Even to non gardeners this disease is pretty well known!
This is the most serious disease of Roses which infects the leaves and greatly affects the plant's vigour from Spring onwards. This disease freely spreads if left untreated from the diseased material to healthy leaves all through the Summer, especially in damp weather.
Photo from RHS website

Here are a few things you can look out for ...

- As the picture shows above infected leaves often turn yellow and fall off by early Summer. This also affects the ripening of flower buds. If your plant has a serious loss of vigour this can affect the whole bush for the following year.

- Dark irregular spots may appear on the leaf stalks and stems, especially on soft growth.

Here are a few things you can do to help prevent this ...

- Remove affected material from the plant as soon as it is spotted and keep checking your plants for any signs throughout the season. All affected material on the plant and any that has fallen to the ground should be collected up and burnt right away.

- Choose Roses that are resistant varieties to plant in your garden, such as Rosa Rugosa.

- Mulching Roses and giving them a feed in Spring can be beneficial against preventing the disease.

Chemical Control can be used with products such as Rose Clear. Spray at the first sight and repeat as per the instructions throughout the season. Try to use these products when pollinators are least likely to be about, example before 8am or after 8pm.

I hope you have found this helpful.

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