ouT, DAmneD SpoT!

As if aphids, vine weevil and lily beetle aren’t trouble enough for gardeners at this time of year, when your roses show signs of blackspot you may wonder if it’s time to throw in the trowel. This unsightly fungal disease is hard to eradicate as it lurks over winter on fallen leaves and diseased stems, spreading on to healthy new leaves as spring returns, causing defoliation and stunted growth. There are many blackspot sprays on the market, claiming to provide a protective barrier which kills fungal spores on the leaves as they germinate. a recent trial by Which? gardening, the Consumers’ association magazine, put eight such products to the test on Silver Jubilee roses as they are a modern variety, more resistant to blackspot than older varieties and more typical of the roses you might buy today. While none of the products completely stopped the disease, testers recommend Bayer garden Systhane Fungus Fighter Concentrate (£5.99 for 300ml, makes 15 litres, available from amazon, Wilkinson, garden centres), Scotts Fungus Clear Ultra (£6.99 for 225ml, makes 15 litres, available from amazon, garden centres) and Bayer garden multirose 2 ready-to-use (£5.75 for 1 litre, available from B&Q, homebase and garden centres).

The full report is in the June issue of Which? Gardening

l If roses are well fed and in the right place, preferably in a sunny spot with good drainage, they’ll be less susceptible to diseases like blackspot

l Which? Gardening magazine tested these products on blackspot on roses