Everything You Need to Know About 9 Common Geranium Diseases

Geraniums are like the sunshine of the garden, spreading happiness with their vibrant, cheerful blooms. These plants seem to thrive effortlessly, but like all living things, they too can fall victim to diseases. However, don’t let that bring you down – it’s a common occurrence and can happen to the best of us gardeners.

Here, we will dive into nine different diseases that can plague geraniums. While some are easily treatable, others can be detrimental if left unchecked. Our goal is to help you identify these issues and tackle them head-on. Let’s take a look at these common geranium diseases:

1. Alternaria Leaf Spot

If you spot raised water-soaked spots on the lower leaves of your geraniums, it might be Alternaria leaf spot. This fungal disease can spread through water or tools, so it’s crucial to water at the soil level and clean your gardening equipment thoroughly.

To combat Alternaria leaf spot, a copper-based fungicide applied every few weeks can help eradicate the issue.

2. Bacterial Blight

Bacterial blight is a serious disease that causes sunken spots on geranium leaves, eventually leading to wilting. Unfortunately, once a plant is infected, there is no cure. To prevent bacterial blight, ensure your tools are clean, water at the soil level, and select healthy plants.

3. Blackleg

Blackleg, caused by water molds in the Pythium genus, can quickly spell disaster for geraniums. This disease can be identified by brown and black rot at the base of the stem, leading to plant death. Using biofungicides like Mycostop can help halt its progression.

4. Botrytis Blight

Botrytis blight targets geranium flowers, causing them to turn brown and fall off. Regular inspections and removing spent flower heads can help prevent the disease. Fungicides and biofungicides are effective treatments for Botrytis blight.

5. Fasciation

Fasciation leads to abnormal leaf growth in geraniums, but it won’t spread to other plants. While you don’t need to remove affected plants, it’s best not to propagate from them.

6. Pseudomonas Leaf Spot

Pseudomonas leaf spot manifests as small spots with dark centers on geranium leaves. Prevention involves maintaining good spacing, watering at the soil level, and using copper fungicides.

7. Root Rot

Root rot can be caused by overwatering or fungi in the Pythium genus. Symptoms include wilting and stunted growth. Reduction in watering and the use of biofungicides like Mycostop can help combat root rot.

8. Rust

Rust is a common disease affecting plants, including geraniums. Yellow spots on leaves and rust-colored spores underneath are characteristic symptoms. Applying copper fungicides regularly can manage rust.

9. Verticillium Wilt

Verticillium wilt causes geraniums to collapse and die without the presence of spots. Seek out resistant cultivars, rotate plantings, and solarize the soil to prevent this fungal disease.

By staying vigilant and taking preventive measures, you can ensure your geraniums remain healthy and vibrant. Keep an eye out for any signs of disease, and address them promptly to enjoy big, healthy geraniums in your garden.

If you’ve encountered any geranium diseases, share your experiences and how you handled them in the comments below. And if you have any questions, feel free to ask!

For more exciting geranium growing adventures, check out our helpful guides on topics like:
– How to Plant and Grow Scented Geraniums
– How to Propagate Geraniums from Stem Cuttings
– 15 of the Best Scented Geranium Varieties

Remember, a little care and attention go a long way in keeping your geraniums disease-free and thriving!