Hi @gardenaculou
Thanks for your question. What a pain it is when plants get sick or attacked by a pest! The good news is most plants do recover, and I believe your Viburnum is suffering from fungal leaf spots, hence the yellow halos around black and brown spots. I think it's mainly down to the weather this year of increasingly damp springs with humid air and relentless rain, so don't worry, it probably couldn't be avoided and isn't anyone fault!
What is Viburnum Fungal Leaf Spot?
Fungal leaf spot is caused by various fungi that thrive in warm, moist conditions. These fungi produce dark, round spots on the leaves, which can merge and cause large areas of dead tissue. It's obvious to see when yellow halos appear around these spots and leaves become heavily mottled.
If left untreated, this can weaken your viburnum and make it more susceptible to other diseases. It won't kill it, but it does look a bit naff and make you panic a bit.
Identifying the Symptoms
- Spots: Look for small, dark brown or black spots on the leaves.
- Yellowing: Leaves may start to turn yellow around the spots.
- Leaf Drop: Severely affected leaves might drop prematurely.
Let's take a look at how to organically treat Viburnum leaf spots without the need for expensive and damaging chemical sprays.
1. Prune and Remove Infected Leaves
- Action: Regularly check your viburnum and prune any infected leaves. Dispose of these leaves in a bin and not the compost, to prevent spreading the fungus. I'd remove the worst of the leaves if possible.
- Why: Removing infected leaves reduces the source of fungal spores and prevents the disease from spreading.
2. Improve Air Circulation
- Action: Prune surrounding plants and thin out dense areas of your viburnum to allow better airflow. This stops stale humid air from allowing the fungus to develop.
- Why: Good air circulation helps keep the foliage dry, making it less hospitable for fungal growth.
3. Watering Techniques
- Action: Water your viburnum at the base rather than overhead. Water in the morning so the foliage has time to dry during the day.
- Why: Keeping the leaves dry reduces the chance of fungal spores germinating and spreading.
4. Mulching
- Action: Apply a layer of organic mulch around the base of the shrub, keeping it a few inches away from the stem. A good peat-free compost or leaf mould will help. In your case, consider giving the hedge a good liquid feed at the base, too to help boost its recovery,
- Why: Mulch helps retain soil moisture and prevents soil-borne fungi from splashing onto the leaves.
https://youtu.be/drHhi8PQyQg
5. Organic Fungicides
- Baking Soda Solution: Mix 1 teaspoon of baking soda, a few drops of liquid soap (like washing up liquid soap), and fill a spray bottle with water. Spray this mixture on the leaves to help prevent fungal growth. Time consuming and not always successful I may add!!
Preventative Measures
- Regular Monitoring: Keep an eye on your viburnum for early signs of fungal leaf spot, especially during humid weather and wet springs.
- Healthy Soil: Maintain healthy soil with organic compost and avoid over-fertilizing, as lush growth is more susceptible to fungal infections.
- Plant Spacing: Ensure your plants are spaced appropriately to allow for good airflow and reduce humidity around the foliage.
I hope that helps. Let us know how you get on!
Lee Garden Ninja
Hi @gardenaculou
Thanks for your question. What a pain it is when plants get sick or attacked by a pest! The good news is most plants do recover, and I believe your Viburnum is suffering from fungal leaf spots, hence the yellow halos around black and brown spots. I think it's mainly down to the weather this year of increasingly damp springs with humid air and relentless rain, so don't worry, it probably couldn't be avoided and isn't anyone fault!
What is Viburnum Fungal Leaf Spot?
Fungal leaf spot is caused by various fungi that thrive in warm, moist conditions. These fungi produce dark, round spots on the leaves, which can merge and cause large areas of dead tissue. It's obvious to see when yellow halos appear around these spots and leaves become heavily mottled.
If left untreated, this can weaken your viburnum and make it more susceptible to other diseases. It won't kill it, but it does look a bit naff and make you panic a bit.
Identifying the Symptoms
- Spots: Look for small, dark brown or black spots on the leaves.
- Yellowing: Leaves may start to turn yellow around the spots.
- Leaf Drop: Severely affected leaves might drop prematurely.
Let's take a look at how to organically treat Viburnum leaf spots without the need for expensive and damaging chemical sprays.
1. Prune and Remove Infected Leaves
- Action: Regularly check your viburnum and prune any infected leaves. Dispose of these leaves in a bin and not the compost, to prevent spreading the fungus. I'd remove the worst of the leaves if possible.
- Why: Removing infected leaves reduces the source of fungal spores and prevents the disease from spreading.
2. Improve Air Circulation
- Action: Prune surrounding plants and thin out dense areas of your viburnum to allow better airflow. This stops stale humid air from allowing the fungus to develop.
- Why: Good air circulation helps keep the foliage dry, making it less hospitable for fungal growth.
3. Watering Techniques
- Action: Water your viburnum at the base rather than overhead. Water in the morning so the foliage has time to dry during the day.
- Why: Keeping the leaves dry reduces the chance of fungal spores germinating and spreading.
4. Mulching
- Action: Apply a layer of organic mulch around the base of the shrub, keeping it a few inches away from the stem. A good peat-free compost or leaf mould will help. In your case, consider giving the hedge a good liquid feed at the base, too to help boost its recovery,
- Why: Mulch helps retain soil moisture and prevents soil-borne fungi from splashing onto the leaves.
5. Organic Fungicides
- Baking Soda Solution: Mix 1 teaspoon of baking soda, a few drops of liquid soap (like washing up liquid soap), and fill a spray bottle with water. Spray this mixture on the leaves to help prevent fungal growth. Time consuming and not always successful I may add!!
Preventative Measures
- Regular Monitoring: Keep an eye on your viburnum for early signs of fungal leaf spot, especially during humid weather and wet springs.
- Healthy Soil: Maintain healthy soil with organic compost and avoid over-fertilizing, as lush growth is more susceptible to fungal infections.
- Plant Spacing: Ensure your plants are spaced appropriately to allow for good airflow and reduce humidity around the foliage.
I hope that helps. Let us know how you get on!
Lee Garden Ninja
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