- Pick off and destroy affected leaves if only one or two show symptoms. Monitor the plants closely for any further development of symptoms
- Severely affected plants should be removed and disposed of as soon as possible. Ensure that no debris remains on the soil surface
- Avoid dense plantings, so that air can circulate freely around the plants
- Avoid overhead watering, particularly where the disease is present
- Do not save seed from affected plants
- If repeated infection occurs, consider replacing lupins with another herbaceous plant
There are no fungicides available to amateur gardeners with specific recommendations for use against lupin anthracnose. However, the fungicides tebuconazole (Provanto Fungus Fighter Concentrate), tebuconazole with trifloxystrobin (Provanto Fungus Fighter Plus, Toprose Fungus Control & Protect), and triticonazole (Fungus Clear Ultra) are labelled for the control of other diseases on ornamental plants, and could therefore be used legally on lupin (at the owner’s risk) to try and control anthracnose.
The following products contain a combination of both insecticide and fungicide, enabling the control of both insect pests and disease: myclobutanil containing cypermethrin (Resolva Rose 3 in 1, Rose Shield Bug & Fungus Killer, Roseclear Ultra Gun 2, Rosegarde) and triticonazole containing acetamiprid (Roseclear Ultra, Roseclear Ultra Gun).When a proprietary product contains an insecticide as well as a fungicide it would be preferable to use an alternative product if pests are not a problem on the plants treated.
There is no specific information available as to the efficacy of these products against lupin anthracnose, however. It is likely that repeated sprays will be required where the disease is present, particularly during unsettled weather. It would be prudent to apply a small amount of the chosen fungicide first, at a solution suggested on the packet for other problems, to ensure that the product will not cause plant damage.
Inclusion of a 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