Q&As/Rose Plant Diseases/Scale on Roses
I have 3 roses with bad scale, I have tried every remedy I can think of including natural. I even resorted to scrubbing last year and lo and behold its back. What can I use to eliminate this? It has not spread to others, yet. Is moving them the best idea?
It is essential to attack the scale during the winter months, with repeated sprays of winter strength horticultural oil. The oil smothers the scales body preventing breathing and leading to the insects death. After two or three applications the scale will be dead, however they will still be attached to the rose bush which may be confusing in that they may still appear alive. At this stage, spray the rose bushes with your garden hose at high fine pressure which should wash off the dead scale insects. If this doesn’t remove all the scale, it may be necessary to attack the problem with a soft scrubbing brush or a firm sponge. This should quite easily remove the dead scale.
It is worth noting that some rose bushes are more prone to scale infestation than others. It may be worthwhile checking the rest of your garden to ensure there are no host plants which may be re-infect your rose bushes. If this is apparent, you will need to remove the infected host plant.
As we enter into the drier summer months, apply Daltons Mulch & Grow around the base of the rose plant to help retain moisture in the soil and prevent weed growth. Apply Daltons Premium Rose & Flower Fertiliser every 5-6 weeks from late October until early December and then recommence late February through to early April. Throughout summer, you can still apply horticultural oil (summer rate) at the first sign of infection and repeat a few times.