I planted a David Austin medium shrub rose "Golden Celebration" last May/June and although it is producing loads of blooms some of the leaves are discoloured in various ways. Some have reddish blotches on them, some with dark brown blotches on the top leaf with the one below it on the same stem yellow or pale green at the edge and a large dark brown blotch over most of the leaf and where it joins the stem. Two smaller leaves below this have the brown where they join the stem and spots of brown on the leaf. Another leaf is very pale green/yellow and that has dark lacey type patterns on it mostly around the edge of the leaf. The rose bush is in a raised bed which is fairly good for draining. The bed is backed by a brick wall that has Clematis and Solanum growing up it and is south facing. It was our 50th wedding anniversary last year so I would be sad to lose this bush so I do hope you can help with this problem. Thanking you in anticipation. Regards. Joyce Lewis.
Certified GKH Gardening Expert
It appears, by the picture sent in to us, that you have a nasty case of Downy Mildew affecting your rosebush. Maybe even a bit of Black Spot fungus trying to join in. The rosebush needs to be sprayed down well with a fungicide that will eliminate and control Downy Mildew. If you can purchase a product called Green Cure where you are, I highly recommend it. It is an Earth Friendly fungicide that is very effective at treating Downy Mildew problems along with other fungal problems. Here is a link to their website with places to purchase it:http://www.greencure.net/ . It comes in little jars or tubs as a white powder that is mixed with water and spray applied to the rosebushes. I have used Green Cure for several years with great success. Be sure to mix it at what they call the Cure Rate on the label instructions. Along with this treatment I recommend watering the rosebush with some water that has both a good root stimulator product and a product called Super Thrive mixed into the same water. Give this to the rosebush the next 4 to 5 times it needs watering. The root stimulator helps the root system be the best it can be and the Super Thrive goes a long way in helping the rosebush deal with the stresses and shock of fungal and insect attacks. A strong and vigorous rosebush has higher resistance to disease attacks. Super Thrive link: http://superthrive.com/ .