Rust looking spots ? - Ask Extension
I have a few house plants,and a fern outdoors, that have, what looks like Rust Spots, on some of the leaves. Is it the soil ? Is it the city water? I...
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Rust looking spots ? #869709
Asked May 23, 2024, 1:36 AM EDT
I have a few house plants,and a fern outdoors, that have, what looks like Rust Spots, on some of the leaves. Is it the soil ? Is it the city water? I'm curious to know, and I have other plants that aren't affected by it.
Marion County Oregon
Expert Response
Dear Delena,
Thank you for contacting us about possible rust on your plants. There are over 7000 different kinds of rust fungus.
The spores are spread by wind and water so they can occur almost anywhere. Warm and wet conditions promote their growth and development. Rusts can appear on foliage as dry spots that are brown, orange, purple, red, or yellow. Often dark specs are encircled by a larger yellow spot.
The best way to prevent rust is to keep the foliage dry (use a drip watering system; water the soil, not the plant) and make sure there is good airflow in and between plants. Use mulch around outdoor plants to prevent infection from rainsplash. Buy only healthy plants, use clean, sterile potting soil, and try to buy plants that are rust-resistant.
Rust is rather difficult to control once a plant is infected. You can remove and destroy badly affected leaves to prevent the further distribution of spores. Different rusts may respond differently to various sprays. You can try commercial sprays formulated for rust/fungal diseases, neem oil, or sulfur.
I hope this information is helpful. Please write again whenever you have a gardening question.
Thank you for contacting us about possible rust on your plants. There are over 7000 different kinds of rust fungus.
The spores are spread by wind and water so they can occur almost anywhere. Warm and wet conditions promote their growth and development. Rusts can appear on foliage as dry spots that are brown, orange, purple, red, or yellow. Often dark specs are encircled by a larger yellow spot.
The best way to prevent rust is to keep the foliage dry (use a drip watering system; water the soil, not the plant) and make sure there is good airflow in and between plants. Use mulch around outdoor plants to prevent infection from rainsplash. Buy only healthy plants, use clean, sterile potting soil, and try to buy plants that are rust-resistant.
Rust is rather difficult to control once a plant is infected. You can remove and destroy badly affected leaves to prevent the further distribution of spores. Different rusts may respond differently to various sprays. You can try commercial sprays formulated for rust/fungal diseases, neem oil, or sulfur.
I hope this information is helpful. Please write again whenever you have a gardening question.
