The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar selection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner.
- Dispose of affected leaves and any that have already fallen as a result of the disease. Note that, as an evergreen plant, escallonia will shed old leaves naturally throughout the year, but the leaf spot can affect leaves of any age
- Affected plants could be cut back hard to stimulate new growth. Fungicide application may be necessary to prevent re-infection (see below). Be aware, however, that plants that have suffered repeated defoliation may be too weak to respond to hard pruning
- Avoid other stresses on the plant – feed regularly and water during prolonged drought
- The disease appears to be specific to escallonia, so in the case of severely affected hedges consider replacement with a different plant
There are no fungicides available to amateur gardeners with specific recommendations for use against escallonia leaf spot. However, the fungicide tebuconazole with trifloxystrobin (Provanto Fungus Fighter Plus, Toprose Fungus Control & Protect) has a recommendation for the control of leaf spots on ornamental plants. Additonally, the fungicides tebuconazole (Provanto Fungus Fighter Concentrate) and triticonazole (Fungus Clear Ultra) are labelled for the control of other diseases on ornamental plants, and could therefore be used legally on Escallonia (at the owner’s risk) to try and control the leaf spotting.
There is no specific information available as to the efficacy of these products against this particular leaf spot, however. It is likely that repeated sprays will be required where the disease is present, particularly during unsettled weather. Success is more likely if the plant is cut back hard to remove affected material, and then sprays applied to protect the new growth. It would be prudent to apply a small amount of the chosen fungicide first to ensure that the product will not cause plant damage.
Inclusion of a fungicide product does not indicate a recommendation or endorsement by the RHS. It is a list of products currently available to the home gardener.
Fungicides for gardeners (Adobe Acrobat pdf document outlining fungicides available to gardeners)
Chemicals: using a sprayer
Chemicals: using safely and effectively
Chemicals: storing and disposing safely