What can I spray on my viburnum to stop the leaves from turning silver?

Hi Virginia,

Thank you for contacting us regarding your Viburnum tree. Gray Silver mottled leaves on Viburnum normally indicates mites infestation. The product you need to apply is Yates Lime Sulphur, Insect and Disease Control. Hope this helps and happy gardening. Best Regards, Louise Yates Horticulturalist