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.
Detailed recommendations are given in the profiles available for rust diseases of individual plants and crops. General recommendations are as follows:
- The development of the disease can sometimes be slowed by picking off affected leaves as soon as they are seen, provided that this involves just a small number of leaves. Removing leaves in large numbers is likely to do more harm than good
- Provide conditions that encourage strong growth, but avoid an excess of nitrogen fertiliser as this results in soft, lush growth that is easily colonised by rust
- All diseased and dead material should be removed at the end of the growing season. The overwintering spores of some rusts are very resilient, so do not compost affected material
- Resistant cultivars are available for some plants and crops, but this resistance is occasionally overcome by genetic changes within the rust fungus
- In some cases no control is required. For example, many rusts of trees develop too late in the summer to have a significant effect on vigour, even though the whole tree may appear yellow or orange in late summer due to the huge number of rust pustules on the leaves
No fungicides are currently available to home gardeners for the control of rust diseases on edible crops.
On ornamental plants the fungicides tebuconazole (Provanto Fungus Fighter Concentrate), tebuconazole with trifloxystrobin (Provanto Fungus Fighter Plus, Toprose Fungus Control & Protect), and triticonazole (Fungus Clear Ultra) are approved for the control of rust diseases.
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.
The foliage and flowers of some ornamentals are sensitive to damage by certain fungicides. Check the product label before use.
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