Black Spot

I have tried everything to rid my roses of black spot, I have roses in various beds with different soil types, drainage etc and once again every rose bush has been affected.  The flowers are gorgeous but the plants themselves are awful, has anyone out there got a remedy or method I may not have tried?

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Posts

  • SalinoSalino Posts: 1,609

    ..this won't please you, but if I had that problem I would have to get rid of all those and plant disease resistant types in their place - there are many available now and there is no need to put up with these martyr's to black spot or mildew or resort to constant spraying....   alternatively do away with roses altogether and plant some nice shrubs like Hydrangeas... Hypericums...   ?  these days I don't put up with problems like that, but I know a lot of people still like to hold on to them, as they often have sentimental value.. and it's expensive to change...

  • Dave MorganDave Morgan Posts: 3,122

    I don't know which roses you have, but what works for me and my customers is this;

    Remove all the affected leaves and burn and check for any fallen leaves under each rose and remove them. Water, feed and mulch every rose. Then spray every rose with fungicide, rose clear is as good as anything, AND spray the ground around each rose. Ensure good airflow around the roses as well.

    The roses look very bare, but I find new growth appears very quickly. Check the new growth and flowers for any sign of reinfection and retreat if necessary following the same process.

    I've done this numerous times and with patience and diligence it works.

    Alternatively do as Salino has suggested and plant resistant varieties, but that isn't always practical or desirable, the choice is yours.

  • Thank you Salino and Dave for your responses, much appreciated. 

  • A local rose grower, who wins medals at RHS shows, told our local hortsoc that even disease resistant new roses only keep their resistance for say 12-15 years when mutations of the various diseases creep up on them. He would then advise replanting with even newer varieties. 

    I also think it pays to do your very first spray very early in the season when you have not much more than bare branches and bud bumps. Follow Dave's advice above , but start very early. depending on how mild the winter has been, you might be thinking of early March. Go out and have a look then.

  • rosemummyrosemummy Posts: 1,983

    wish i'd read dave's advice an hour ago..my honeysuckle had horrendous whitefly and blackspot..been spraying for couple of weeks, leaves were brown and crispy...just went mad and cut the lot down to 8 inches from the ground

  • treehugger80treehugger80 Posts: 1,407

    been talking with David Austin Roses about mine and they recommend a high potash fertilizer and give your rose a good mulch (after watering) as it can be sign the rose (or anything else) is water stressed. make sure you removed and dispose (in a bin- not compost) the effected leaves

  • Thank you Woodgreen wonderboy

  • rosemummyrosemummy Posts: 1,983

    funnily enough my honeysuckle was next to rose and rose only had a couple of blackspots on odd leaf, removed and plant fine

  • Dave MorganDave Morgan Posts: 3,122

    Rosemummy, is your honeysuckle dry at the roots? Soak it regularly and mulch it, honeysuckle will recover from black spot and mildew, it just needs moisture and in this weather the ground is drying out very quickly. I soak mine once a week and keep the roots shaded, works every time, no need to spray.

  • rosemummyrosemummy Posts: 1,983

    Oops. Bit late Dave. Is now 8 inches tall. got fed up of whitefly literally covering it and didn't want them to spread, leaves were brown, crispy, fell off in my hand, just was seized by a desire to clean the area becore rose got covered, maybe it eill recover, if not I may replace with another that I actually know what variety it us!

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