Q.viburnum leaves have brown spots
I have a Viburnum tinus ‘Gwenllian,’ which is about 18 months old. It has recently developed large brown spots on the leaves and my gardener says it is incurable. Please advise. The shrub is positioned in a rose bed (as the roses become old, I am replacing with shrubs). The ground is alongside my driveway and probably has more subsoil in it than it should have, although over the years the roses have done well, and I have treated those with rotted manure regularly. I would like to know what the problem is and how to treat it, please.
Do your leaves look like this?: http://nassau.ifas.ufl.edu/assets/horticulture/gardentalk/shrub/viburnubacterialblight.jpg
If so, your viburnum probably has bacterial blight. More information on bacterial blight, along with recommended treatment, can be found here:
https://bit.ly/1yj22zB
If you determine that the issue is not bacterial blight, then I would recommend reviewing the following article which discusses viburnum diseases and insect pests:
http://www.clemson.edu/extension/hgic/pests/plant_pests/shrubs/hgic2057.html
For more information about viburnum shrubs, please visit the following link:
https://www.gardeningknowhow.com/ornamental/shrubs/viburnum/
