In January 2023 LSU AgCenter identified a major pathogen in the Wild Garden called Rosellinia root rot. Seldom seen in ornamental landscapes it spreads rapidly through soil invading other plant materials and quick action is necessary to stop the spread. Here’s what you should know to manage this disease.

First, become familiar with identifying this pathogen and related damages. Also known as white root rot the mycelia fungus is often seen on lower tree trunks and plant roots. Beginning symptoms include yellow foliage and wilting in areas of the canopy eventually entire crown and plant dies.

Second, knowing host plants can be helpful. However, a complete host range is not known but the disease covers a wide range of plant materials like Viola, Callicarpa americana, Camellia sinensis, Dianthus, Begonia Narcissus, and over 300 species of woody plants.

Third, life cycle is important because pathogen can live in the soil for many years as mycelia on infected tree roots, dried contaminated bark/wood, and organic matter. Saturated or moist soil will enhance mycelium growth from infected roots throughout the soil profile. When mycelia touch uncontaminated root systems, this will cause infection of healthy plants leading to quick death.

Finally for management, plants infected with Rosellinia root rot should be removed immediately including all roots and large volumes of soil and replaced with new topsoil. To reduce pathogen infestation, replant on soil mounds for better drainage around plant roots and turnoff any overhead irrigation system in that zone.

No registered fungicides have been shown to cure this disease. But since last summer I have been applying MicroLife products of Super Seaweed, Molasses, and Micro Gro Bio Inoculant to the soil and foliage application of plants in the pathogen zone area. Currently, these products are showing some promise in being able to grow healthy plants while helping to keep pathogen levels under control. Just recently I identified some Rosellinia on salvia roots and applied these products on the infected plant in a nursery container and will continue observing overall plant health for progress. To learn more about the benefits of these amazing products visit microlifefertilizer.com

Happy Gardening,

Simeon Benjamin

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