Quote from Lee Garden Ninja on 4th April 2024, 8:03 am

Hi @nickyb

Thanks for your comment about your Viburnum.

I believe this one is Viburnum davidii. Hard to tell without seeing the leaf in full colour! I think you're right about the Botryosphaeria attacking the plant and causing the damage.

What is Botryosphaeria?

Botryosphaeria is a genus of fungi that includes several plant pathogens known to cause diseases in a wide range of woody plants, including trees, shrubs, and vines. These fungi typically infect plants through wounds or stressed tissue, leading to various symptoms such as cankers, dieback, leaf spots, and fruit rot.

Botryosphaeria infections can weaken or kill affected plants, posing significant challenges to gardeners and the world of horticulture. Don't worry, though, Nicky it's actually quite common, usually from wet summers after the shrub has been pruned or damaged by wind/animals.

How to cure Botryosphaeria or Viburnum brown leaves

Treatment methods for Botryosphaeria infections in plants typically involve a combination of cultural practices, i.e. things the gardener can do themselves with tools or homemade remedies and chemical control, i.e. sprays, and fungicides. Here are some common treatments.

• Pruning: Remove infected branches or cankers from the plant, making sure to cut several inches below the visible symptoms. This helps prevent the spread of the disease to healthy tissue. Always use clean sharp secateurs.

• Sanitation: Clean pruning tools between cuts to avoid spreading the fungus to healthy parts of the plant or other plants in the vicinity. Dispose of infected plant material properly to prevent further contamination or even burn infected material Nicky, never compost or throw on a muck heap as the fungus survives and then spreads.

• Promoting Plant Health: Maintain optimal growing conditions for the plant, including proper irrigation, fertilization, and mulching. Healthy plants are better able to resist disease and usually a good peat free compost mulch twice a year helps.

• Fungicides: In severe cases, especially in commercial orchards or nurseries, fungicides may be necessary to control Botryosphaeria infections. However, these can cause more harm than good as they drift onto other plants and into the ecosystem, affecting beneficial fungi.

• Avoiding Stress: Minimize environmental stressors such as drought, excessive heat, or injury to reduce the plant's susceptibility to Botryosphaeria infections. If a branch gets damaged in summer, prune it straight off.

• Monitoring: Regularly inspect plants for symptoms of Botryosphaeria infection, such as cankers, dieback, or leaf spots. Early detection allows for prompt intervention and better disease management.

Unfortunately, Nicky, looking at your Viburnum, it's not going to survive. I would dig it up, chop it up and bin it. However, you can still plant in its place, just make sure you rake up any fallen leaves or pruning material so the fungus can't continue.

Also don't lose hope, all of us Garden Ninjas, even I, lose plants to disease every now and then. I'm just glad you're clever enough to deal with it rather than just ignore it!

All the best

Lee Garden Ninja

Quote from NickyB on 4th April 2024, 9:44 am

Thanks so much for getting back to me and confirming my worst fears - looking back I think it's been brewing for a few years and came to a head this year and last.