Camellia can often be easy plants to grow, but, as always, there are a number of things that can go wrong.
Brown spots on camellia leaves can be an early indication of one or a number of problems.
Brown Spots on Camellia Leaves: Causes and Solutions
Camellias are prized for their glossy evergreen foliage and abundant colorful blooms. However, the leaves of camellias can sometimes develop unsightly brown spots that mar their beauty. If you notice brown spots on the leaves of your camellia plants, don’t panic. In most cases, the problem is easily treatable if caught early. Let’s examine the various causes of brown spots on camellia leaves and what you can do to fix them
Common Causes of Brown Spots on Camellia Leaves
There are several potential reasons you may see brown spots on camellia foliage:
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Fungal diseases like anthracnose and leaf spot fungi can cause the formation of brown lesions on leaves. The spots often start small but can expand and merge. They may have defined borders or irregular shapes. High humidity favors these fungal infections.
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Bacterial infections such as bacterial leaf spot also lead to brown spots often surrounded by yellowing. Bacteria spreads rapidly in wet conditions.
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Pest damage from bugs like spider mites, scale, aphids, and thrips results in stippled spots as the pests suck sap from leaves. The damaged areas dry out and turn brown.
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Sunscald happens when leaves are suddenly exposed to excessive direct sun. This causes sunburn-like tan or brown papery spots on leaves.
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Frost damage shows up as brown patches, especially on older leaves. Dry winter winds cause moisture loss from leaves faster than roots can absorb water.
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Chemical damage from concentrated pesticides or fertilizers can burn and damage the leaf tissue. Alkaline water with high pH can also cause spotting.
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Nutrient deficiencies of nitrogen, iron, magnesium and manganese leads to yellowing and browning, usually starting at the tips and margins of leaves.
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Improper watering like overwatering or irregular watering puts stress on the plant and can cause leaf spotting.
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Root rot causes wilting and yellowing leaves that eventually turn brown all over.
Treating Brown Spots on Camellia Leaves
The best treatment depends on the underlying cause behind the brown spots:
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For fungal or bacterial infections, prune off affected leaves and spray the plant thoroughly with copper fungicide/bactericide.
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With pest damage, manually remove pests and apply insecticidal soap spray. Release beneficial insects to control populations.
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For sunscald, move plant to filtered light location. Drape shade cloth to protect tender foliage.
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To prevent frost damage, provide winter wind protection, insulate roots by mulching and maintain even soil moisture.
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Chemical damage requires flushing soil to wash away excess salts, fertilizers. Test and amend irrigation water pH if high.
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Nutrient deficiencies are corrected by applying balanced organic fertilizer, based on soil test results. Chelated supplements can help too.
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For underwatering issues, improve watering practices and mulch well to conserve moisture. Check roots for rot and repot if required.
Preventing Brown Spots on Camellia Leaves
Follow good cultural practices to avoid issues that cause brown spots on camellias:
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Select disease-resistant camellia varieties like Camellia japonica and Camellia sasanqua.
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Grow camellias in sites with morning sun and afternoon shade to prevent leaf scorching.
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Water thoroughly and regularly to maintain even soil moisture. Deep weekly soakings are better than frequent shallow watering.
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Prune strategically to open up interior of shrub and improve air circulation.
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Apply balanced organic fertilizer or acidic supplements to camellias in early spring.
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Use preventive copper spray before rainy/humid weather to deter fungal diseases.
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Promptly rake and remove fallen diseased leaves and flowers from the ground.
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Control camellia petal blight by collecting and disposing infected blooms.
Sun Scorch
Leaves can also turn brown in places during the summer when the weather is particularly hot and the sun is fierce.
Remember, most camellias are best grown in partial or dappled shade, where they are protected from solar rays.
Sun scorch can usually be avoided by carefully positioning a camellia so that it is protected from the sun in summer.
Again, as above, a problem with brown spots or leaves caused by seasonal variation is not life-threatening.
Simply remove the affected foliage and the plant should have no problem recovering.
Brown patches on leaves that seem damp and watery are often a sign that the camellia has been overwatered or that excess water could not drain away.
If you think that you have overwatered your camellia, reduce watering right away and water only when the top few centimetres of the soil or growing medium is dry.
Take steps to improve drainage and hopefully it won’t be too late to allow the plant to recover.
Frost Damage
Brown spots on the leaves of a camellia plant can often be caused by frost damage.
In winter, when the temperatures are low, cold winds can cause water to evaporate from leaves more quickly than it can be replenished from the roots.
This can cause the leaf tips and upper leaves on your plant to turn brown in places.
Remember, some camellias are hardier than others, so when choosing and positioning a camellia, it is always important to look at whether the particular type and cultivar you are considering can cope with the winter conditions where you live.
Fortunately, frost damage will usually be a temporary problem.
You can simply remove the affected foliage and the plant will usually recover just fine in spring, putting out new growth.
How to fix yellow and brown leaves on a Camellia bush.
FAQ
How do you treat brown spots on leaves?
Brown spots on plant leaves can be caused by various factors, including fungal or bacterial infections, pest infestations, or improper watering.
How do you treat camellia leaf disease?
Treatment is simple-prune off and dispose of the affected growth in the trash (in a closed plastic bag to avoid spreading the disease) as soon as you notice it.May 20, 2015
What causes camellia leaves to turn brown?
Camellia leaves turning brown can be caused by several factors, including temperature stress (frost damage or sun scorch), fungal diseases, and watering issues.
How do you treat camellia fungus?
Fungicide sprays recommended for the flowers include mancozeb. Application of soil drenches, such as mancozeb or captan, around the plant every 2 weeks from late December through January may be helpful in reducing the intensity of disease.