who made the diagnosis ...???

i would have expected complaints of mildew on lilac... long before i ran up to leaf spot ...

and i would never bother to treat PM on lilac.. its cosmetic.. the spray wont remove it.. though kill it ... so you end up using chems or whatever... for what amounts to nothing ...

can we have some pix.. to see what is going on.. before we encourage you further ???

you confused me.. by calling a viburnum.. a rose ...

ken

Lime/sulfur spray is applied to fruit trees in late winter. Spraying it on anything at this time of year will destroy all foliage.

Here's what on the guelder rose

On the charles joly

Click on the small box in guelder rose post
I was told by a guy in my local garden centre it was leaf spot is there any universal fungicide that kills all fungi on plants

If you've already applied bordeaux mixture, then you need to just stop. Spraying one fungicide after another is going to burn the foliage. Once spots appear, they will not go away -- fungicide will prevent more spots from developing but the existing spots will remain for the rest of the growing season. if you don't like the appearance of the shrub with spotty leaves, you can pluck off the damaged leaves, water well and wait for new foliage to appear. Good luck.

Actually, neither plant is affected by a fungal problem - they both have a bacterial leaf spot known as 'lilac blight', Pseudomonas syringae. The Bordeaux mix is a recommended treatment for this problem however in a mild, damp climate, adding some sort of surfactant (spreader sticker) to the mixture will give longer lasting effectiveness. And it is important to note that this treatment is not going to be curative - the best it can do is prevent the disease spreading to unaffected foliage.

The good news is this disease on many woody shrubs (like these) is considered more cosmetic than harmful. Make sure you follow good cultural practices by cleaning up all the foliage in the fall and destroying it and perhaps even utilizing a dormant spray to kill any overwintering infection. It is also suggested that liming the soil may limit the development of the problem.