Can you use olive oil with detergent to spray for rust on frangipani tree in...
Thank you for contacting us. Rust disease is best treated with a commercial fungicides, many of which contain copper or sulphur. Neem oil may also be effective. Follow the product instructions carefully.
Other oils and soaps are not effective against rust. Further, detergents should never be used because they contain surfactants which can damage plants.
Sanitation is very important in controling rust. Remove affected leaves if possible and burn them (do not compost infected leaves.) Also keep the ground clear of any leaves year round. The disease can persist through the winter on plant debris. Mulchng may also help to prevent the pathogen from spreading. Try to avoid getting foliage wet when watering, and keep trees pruned and spaced so there is good airflow.