Black Spot on Roses - New Gardener
I've just moved into a flat with my first garden (very excited!), which has lots of rose bushes. The garden was obviously loved at some point, but has been neglected recently and some of the rose bushes have black spot. I've researched a few treatments (although I'd love recommendations), but my big question is how to deal with a rose which has nearly all leaves infected? I know I'm supposed to prune all the infected leaves, but there won't be much left.
Should I go ahead and prune it now? Just cut off the worst cases, treat and cut it back hard when the leaves start dying back in autumn? Or is this a lost cause and should I ask the landlord if I can dig it up and replace it with a black spot resistant strain?
Thanks in advance for the advice.
There's not much you can do at this point in the season, Gemma. You certainly can't treat the problem. If you're going to spray against black spot it has to be on a preventive basis, very early in the season, before the fungal spores arrive on the leaves.
You might as well take off all the affected leaves and destroy them. Most importantly, collect any affected leaves already on the ground - from all the plants - and destroy them too. Bin them or burn them. A lot of black spot problems arise from diseased leaves left on the ground.
The plant should come back next spring. And, if you want to spray against the disease, do it early.
Thanks Italophile - I'll do as you suggest and get rid of as many diseased leaves as I can, and be ready to spray next summer - fortunately the roses in the front garden seem to be unaffected so I still have pretty flowers to enjoy!
Hi Gemma sorry about your roses. I have read about spraying early, keeping things clean (no dead diseased leaves) i have tried all this for the last two years BUT im afraid this year blackspot everywhere even on my cuttings struck last year kept away from the rest HELP.......
Black spot is a fungal disease and that's the problem with fungal diseases. The spores are airborne, invisible to the naked eye, and everywhere. All a spray can do is coat the leaves - on both sides - to make life more difficult for the spores getting a grip. It doesn't guarantee freedom from disease. If only it did.
I have the same problem with a new rose bed I planted with Darcy Bussel last year. What I want to know is should I completely strip the roses of all their leaves and prune the bare wood back now or leave it till the early spring???