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Jasmine is a popular and fragrant flowering plant that can add beauty and perfume to gardens and patios. However, jasmine plant owners may notice troubling red spots appearing on the leaves, especially during rainy, humid weather. These reddish-brown spots can spread rapidly, causing leaves to curl and dry out
If your jasmine plant has developed red spots don’t panic! This common problem is usually caused by one of two fungal diseases – leaf-blight or alternaria leaf spot. While these infections can damage the plant’s foliage and affect flowering they can be successfully treated and controlled when the proper steps are taken.
In this article, we’ll cover the key causes of red spots on jasmine leaves along with proven solutions to treat and prevent outbreaks. With some good plant care and vigilance, you can get your jasmine back to making fragrant white blossoms again.
What Causes Red Spots on Jasmine Leaves?
There are two main culprits behind reddish spots appearing on jasmine foliage:
Leaf-Blight Fungus
Leaf-blight, caused by the fungus Cercospora jasminicola, is a common disease affecting jasmines. It first appears as small circular spots on the upper sides of leaves
The spots rapidly enlarge to about 1⁄4 inch across and turn reddish-brown or purple with slightly raised centers. Severely infected leaves yellow, wither, and drop off.
Leaf blight thrives in warm, humid, rainy conditions, spreading quickly during summer monsoons. It’s most damaging to certain jasmine species like Jasminum grandiflorum (Spanish jasmine) and Jasminum sambac (Arabian jasmine).
Alternaria Leaf Spot
The fungus Alternaria jasmini causes a very similar leaf spot disease on jasmines. It starts out as small reddish spots that expand, eventually turning the whole leaf brown.
Alternaria also spreads rapidly in hot, humid weather leading to leaf drop. And it can severely weaken plants by defoliating jasmine bushes entirely.
Both leaf-blight and alternaria infect plants through damaged or stressed tissue. While they look almost identical, lab testing can differentiate between the two fungi. Proper treatment is the same for both.
How to Treat Red Spots on Jasmine
If your jasmine shows early signs of reddish spotting on leaves, taking quick action can help limit damage. Here are effective treatment options:
Remove and Destroy Infected Leaves
Prune away all leaves with spotting, making sure to collect them. Don’t compost diseased leaves, as the fungi could spread. Throw the leaves away or burn them.
Removing infected foliage prevents further spreading spores from being released. Disinfect your pruning shears after each cut with rubbing alcohol.
Improve Air Circulation
Leaf-blight fungi thrive in stagnant, humid conditions. Improve airflow around plants through strategic pruning and spacing. Consider adding a fan to keep air moving around jasmine.
Apply Fungicidal Spray
Treat remaining foliage with a commercial broad-spectrum fungicide containing chlorothalonil, myclobutanil, or thiophanate-methyl. Follow label instructions carefully.
Repeating applications every 7-14 days may be needed to control the disease during rainy periods. Always alternate between fungicide classes.
Increase Sunlight Exposure
Getting more sunlight on your jasmine encourages faster drying of leaves, creating an environment less hospitable to fungal diseases. Prune or trim nearby plants that may be shading the jasmine.
Water at the Base
Avoid getting water on the jasmine’s foliage when irrigation as this can promote fungal growth. Water deeply at the soil line only.
Use Drip Irrigation
Overhead watering spreads fungal spores. Installing drip irrigation or soaker hoses keeps leaves dry while watering the roots.
Clean Up Debris
Remove all fallen jasmine leaves, flowers, and debris from around the plant. These harbor fungal spores that can reinfect the plant.
How to Prevent Red Spots on Jasmine
Once you’ve tackled an active leaf spot outbreak, focus on prevention to stop recurrence next season:
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Inspect plants routinely and remove diseased leaves immediately.
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Disinfect tools after pruning infected plants.
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Allow good airflow and light exposure through proper spacing and pruning.
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Water early in the day so leaves dry fully.
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Apply fungicide sprays preventatively before rainy periods.
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Avoid overhead watering methods.
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Clean up all fallen leaves and petals around plants.
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Propagate new jasmine plants from cuttings of disease-free specimens.
Are Red Spots on Jasmine Dangerous?
Leaf-blight and alternaria fungal diseases mainly affect the aesthetics of jasmine by causing unsightly spotting, curled leaves, and defoliation. They rarely kill the plant unless left uncontrolled for multiple seasons.
However, losing too much foliage can weaken the plant, leaving it stressed and struggling to thrive. Ongoing defoliation prohibits flowers and leads to reduced vigor. It also detracts from the jasmine’s ornamental beauty in landscape plantings.
So while not immediately fatal, red leaf spotting should be addressed promptly. With proper care, the plant can recover and regrow new healthy leaves and flowers again.
Common Jasmine Species Affected
All jasmine species and cultivars are susceptible to leaf-blight and alternaria to some degree when conditions are right, but some are more prone to problems:
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Jasminum grandiflorum (Spanish jasmine) – Very susceptible to severe leaf blight infections.
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Jasminum sambac (Arabian jasmine) – Highly vulnerable to rapid leaf spotting.
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Jasminum polyanthum (Pink jasmine) – Moderately affected by fungal diseases.
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Jasminum officinale (Common white jasmine) – Less bothered by leaf spots but still possible.
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Jasminum nudiflorum (Winter jasmine) – More resistant with less frequent issues.
If a particular jasmine variety has proven extra prone to fungal problems in your climate, consider replacing it with a more disease-resistant species.
When to Call a Professional
For minor spotting detected early, home treatment is often effective. But if you see:
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Extensive spotting spread across the majority of leaves
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Dieback of stems and whole sections of the plant
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Recurring infections not resolved with treatment
Consult a professional horticulturist or certified arborist. They can assess if a more serious disease is involved and provide science-backed solutions. They may also recommend replacing susceptible jasmine varieties with improved cultivars or alternative plant choices.
Can Jasmine Fungal Diseases Spread to Other Plants?
The fungi that cause jasmine leaf spot diseases are host-specific pathogens that only infect plants in the genus Jasminum. They cannot spread to totally unrelated plants like roses, magnolias, vegetables, etc.
However, fungal spores could potentially jump to your other jasmine plants nearby. To prevent this, always disinfect tools after pruning infected jasmines. Space jasmine plants widely and improve their sunlight exposure.
What Does Healthy Jasmine Look Like?
When a jasmine plant is happy and thriving, you should see:
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Bright green, unblemished leaves.
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Bushy, full foliage.
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White, pink, or yellow flowers blooming heavily.
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No dropping leaves or petals.
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Active new growth and shoots.
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No signs of insects, webs, or damage.
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Clean stems and branches with no ooze or rot.
Key Takeaways
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Reddish circular spots on jasmine most often indicate a fungal infection, either leaf blight or alternaria leaf spot disease.
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Humid, rainy conditions cause epidemics, spreading spores.
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Removing infected leaves along with fungicide sprays is key to treatment.
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Preventive care like pruning for sunlight and airflow keeps jasmines healthy.
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Leaf spot diseases mainly affect the appearance and vigor but rarely kill jasmines.
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Prompt action at the first sign of symptoms offers the best solution.
Pay close attention to your jasmine’s leaves and take quick action if any suspicious spots appear. With vigilant monitoring and care focused on promoting good air circulation and avoiding excess moisture, your jasmine can continue rewarding you with abundant green growth and heavenly fragrant blooms.
How to fertilize daphne?
Q: My fragrant daphne is blooming now, but many of the leaves are yellow. It looks to me like it needs fertilizer. Does it take azalea fertilizer, or would aged chicken manure (well-watered in), or something else do the trick?.
A: I am presuming you have Daphne odora, winter daphne. This is a somewhat touchy plant. Like most broadleaf evergreens it responds to severe stress by shedding the older leaves. Staking and firming the soil are good first steps. Next, you might want to put about 2 inches of good compost around the plant, making sure not to pile it up against the main stems. You could also add a small amount of cottonseed meal, an organic acidic fertilizer under the compost. Do not over-fertilize a stressed plant.
– Jack Shorr, OSU Extension Master Gardener
Is this camellia suffering from a lack of nutrients?
How to help this star jasmine?
There are some star jasmine plants in my front yard whose leaves have reddish spots all over them. Is there a treatment I can apply to rehabilitate them?.
A: Here is an article that explains some of these plants’ problems, and this one has suggestions for what to do with brown leaves. As they indicate, brown leaves of this pattern are typically a temperature (too low or too high) problem, or leaf or winter scorch. Since I don’t know whether the browning began last summer during the dry weather, or just began over the winter, it is difficult to know its origin. Try cutting out the brown as soon as the weather gets above 45 to 50 degrees during the day (when it should be above freezing at night), and see if it returns.
– Jack Master, OSU Extension Master Gardener
Winter Daphne, Daphne odora, flowers in April in the Pacific Northwest. Photo by Marci DegmanMarci Degman
Common disease in Jasmine /मोगरा. Blossom Midge/ Budworm.
FAQ
How do you treat jasmine leaf spots?
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Products
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Technical Names
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Dosages
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K ZEB
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Mancozeb 75% WP
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500gm per Acre
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Boost
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Propiconazole 25 % EC
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200-300 ml per acre
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KTM
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Thiophanate Methyl 70% WP
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250-600 grams per acre
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Hexa 5 Plus
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Hexaconazole 5 % SC
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200-250 ml per acre
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What are the rust spots on jasmine leaves?
Should jasmine leaves turn red?
How do you treat jasmine fungus?
What diseases affect jasmine plants?
Leaf Spot Leaf spot is another fungal disease that affects jasmine plants. It is characterized by the appearance of small, dark spots on the leaves. As the disease progresses, the spots may expand and merge, eventually leading to the death of the affected leaves.
What is a leaf spot on star jasmine?
These spots may be brown, black, or reddish in color and can gradually enlarge over time. To treat leaf spot on star jasmine, start by removing any infected leaves and disposing of them properly to prevent further spread of the disease.
What are the spots on my jasmine plant?
Other insects such as white flies will lay eggs under the plant’s leaves, which look like spots. Jasmine isn’t prone to insect pests, but it isn’t immune to them either. A good shower will usually knock the insects off the plant. If the spots are circular, reddish brown and less than half an inch across, the flower may have Cercospora leaf spot.
What causes red leaves in star jasmine plants?
In summary, the main causes of red leaves in star jasmine plants are natural seasonal changes, water stress, nutrient deficiencies, and plant stress. To maintain a healthy and vibrant star jasmine, be mindful of its needs and provide the appropriate care based on your region’s climate and seasonal changes.