This year my redcurrant bushes are covered in a black sooty substance. What causes this and how can i tackle it.
Sooty mould is caused by aphids. Their sticky sap takes up the mould spores. Improve ventilation around the plants. Wash off if the ants are harvesting the sap (lots of ants around running up the stems etc) try to get rid of the ants. Use soapy suds from washing up liquid - put into a sprayer, shake and use the bubbles to coat the leaves and the aphids. Will get washed smell nice and hope to get rid of the aphids. you May need to repeat. Or you can move the ants off, add ladybird larva and ladybirds to hope to get rid of the aphids.