Q.Dark Patches On My Clematis Leaves
Strange disease where the plant has very vigorous growth at the top but once the leaves form, they pick up this black coloured patches then slowly die. I’ve used insecticide, fungicide, slug protection but nothing helps. I don’t want to write it off if there’s a chance of saving it. It’s in its second year planted beside a wall.
Certified GKH Gardening Expert
This appears as a phosphorus deficiency. I would be sure to test your soil for deficiency or nutrient/pH imbalances.
Likely, the soil is too acidic, fed a fertilizer that is too high in nitrogen, or there is an actual phosphorus deficiency.
Here are some articles that will help: