Guide to Mulberry Tree Disease, Pests & Common Problems

Mulberry trees are renowned for their delicious fruit and beautiful leaves. However, like all plants, they are vulnerable to a range of pests and diseases.

This guide aims to provide an understanding of common mulberry tree problems and offer solutions to maintain a healthy tree. Let’s get into the details.

Even though mulberry trees are hardy and quite self-sufficient, there are some key tips to their care you should know. I explain it all in my comprehensive guide, Mulberry Trees 101. It’s a must-read!

Mulberry Tree Diseases

Understanding mulberry tree diseases is essential for good tree care. They can lead to significant damage to the fruit, leaves, and even the entire root system.

Here, we’ll explore some common diseases and how to identify, prevent, and treat them.

Powdery Mildew

Powdery mildew manifests as white powdery patches on the mulberry leaf surface. These white powdery patches turn yellow, leading to leaf drop.

The disease can spread rapidly in humid conditions, affecting young leaves and shoots and leading to premature leaf drop.

To prevent this disease, prune the mulberry tree regularly to improve air circulation, avoid overhead watering to keep the leaves dry, and spray with fungicides like neem oil if powdery mildew is a common problem in your area.

To treat existing infections, remove infected leaves and branches, and apply fungicides containing sulfur or neem oil.

False Mildew

False mildew is also known as downy mildew. It affects the lower surface of the leaves and appears as pale green to yellow spots on the upper leaf surface.

A whitish or grayish fuzz can be found underneath, especially in humid weather. Affected areas may turn brown and lead to leaf drop.

To prevent this disease, plant resistant mulberry varieties, practice good tree care, ensure proper spacing and pruning, and avoid overhead watering, which can create a humid environment conducive to fungal growth.

To treat existing infections, remove diseased leaves and twigs, and apply fungicides specifically designed to treat downy mildew.

Leaf Spot

Leaf spot causes black or brown spots to appear on mulberry leaves. Infected leaves can turn yellow, leading to leaves falling from the tree.

Pruning diseased branches and spraying fungicides can prevent and treat this disease.

Bacterial Blight

Bacterial blight causes the leaves to develop dark brown spots with a characteristic “shot hole” appearance.

Regular pruning of infected branches and applying copper sprays can manage this disease.

Bacterial Leaf Scorch

This disease causes discolored leaves that may turn yellow or bronze. It spreads through insects.

Preventive measures include keeping healthy trees and controlling insect infestation. Infected leaves should be pruned and destroyed.

Rust

Rust appears as irregular spots on the underside of the leaves, leading to yellow leaves. Pruning and spraying fungicides can control this fungal disease.

Armillaria Root Rot

Armillaria root rot affects the entire root system, causing roots to rot and leaves to turn yellow.

Prevent the disease by avoiding planting in previously infected soil, and treat with appropriate fungicides, like this one.

Cotton Root Rot

Also known as Texas root rot, cotton root rot causes mulberry leaves to turn yellow or bronze and affects the roots.

Treatment includes removing infected plants, and prevention involves not planting anything for at least five years in the affected area.

Canker Disease

Canker is marked by fungal growth near the root or on twigs, leading to stunted growth. Regular pruning and applying fungicides can prevent and treat canker in mulberry trees.

Mulberry Ringspot Virus

This virus leads to yellow rings on mulberry leaves and can result in stunted growth.

Prevention includes controlling the pests that spread the virus, but there’s no known cure once the tree is infected.

Dwarf Disease

Dwarf disease occurs in young trees, causing them to grow slower. Regularly monitoring the trees and applying necessary fungicides can prevent this disease.

Fusarium and Verticillium Wilt

These wilts cause mulberry leaves to become yellow, and infected leaves fall to the ground soon after yellowing occurs.

Pruning and applying suitable fungicides are the preventive and treatment measures.

Wetwood

Wetwood leads to oozing liquid from the trunk. Properly draining the soil and avoiding excess watering can prevent this disease.

Popcorn Disease

Popcorn disease is characterized by mulberry fruit turning into whitish, popcorn-like masses.

Removing and destroying infected fruit and applying appropriate sprays can control this disease.

Mulberry Tree Pests

Pests can cause significant damage to mulberry trees. From leaf rollers to nematodes, understanding the signs of infestation and methods of control is crucial for healthy trees.

Mealybugs

Mealybugs are very small and oval in shape with a fuzzy appearance. They cause mulberry leaves to turn yellow. Using insecticidal soap or neem oil as a spray can control these pests.

Leaf Rollers and Leaf Hoppers

Leaf rollers and leaf hoppers are common pests that damage mulberry foliage. Spraying insecticides and maintaining good tree care practices can control them.

The glassy-winged sharpshooter, a specific type of leafhopper, is particularly harmful.

Various Worms and Caterpillars

These include the Bihar hairy caterpillar, webworms, cutworms, and more.

Caterpillar larvae can infest mulberry leaves, causing them to turn yellow. Spraying appropriate insecticides can control these pests.

Grasshoppers

Grasshoppers may cause massive mulberry leaf damage with their insatiable appetites. Regular monitoring and using insecticidal sprays can prevent and treat infestations.

Thrips

Thrips infest the lower leaf surface, causing foliage discoloration. Insecticides and neem sprays can control these pests.

Whitefly

Whiteflies are small insects that can cause yellowing of mulberry leaves. They look like miniature moths and rise off the tree like a cloud when disturbed. Spraying insecticides can manage this infestation.

Scale Insects

Scale insects look like tiny bumps and attach to branches and trunks, causing yellow leaves and stunted growth.

Pruning infected branches and using appropriate sprays can control them.

Stem Borers

Stem borers tunnel under the bark and feed inside the branches and stems. They can cause severe damage to mulberry tree branches.

Pruning infected branches and spraying insecticides can prevent and treat this problem.

Beetles

Japanese beetles and other beetles chew mulberry leaves, causing them to turn yellow. Insecticidal sprays, traps, and regular monitoring can control these insects.

Termites

Termites may attack mulberry tree roots, leading to weakened trees. However, most termites feed on dead wood, so seeing these pests may indicate a larger problem.

Using appropriate insecticides can prevent and treat termite infestations.

Aphids

Aphids are small insects that are typically green or whitish. They suck the sap from mulberry leaves, causing them to turn yellow. With aphids, you may also notice ants, which “farm” the aphids.

Spraying insecticidal soaps can control aphids.

Spider Mites

Spider mites are so small that they can be hard to spot, but you’ll likely see the proof of their presence — fine webbing.

Spider mites can cause yellowing and falling of mulberry leaves. Insecticidal sprays are effective in controlling these pests.

Fruit Flies

Fruit flies are small flying pests that attack the fruit of the mulberry tree, leading to spoilage.

Regular monitoring and spraying appropriate insecticides can prevent and treat this problem.

Nematodes

Nematodes attack the roots of the mulberry tree, leading to stunted growth. Soil treatments and using resistant varieties can prevent and control nematodes.

Weevils

Weevils have distinctive snouts and like to chew on mulberry leaves, leading to brown spots. Insecticidal sprays and good tree care practices can prevent and treat weevil infestation.

Lacebugs

Lacebugs damage the lower surface of the leaves, leading to yellowing. Regular monitoring and using appropriate insecticides can control lacebugs.

Mulberry Tree Common Problems

Apart from diseases and pests, mulberry trees face other common issues. Addressing these mulberry tree problems requires proper understanding of the issue at hand.

Leaf Issues

Leaf issues like yellowing or brown spots may result from nutritional deficiencies or overwatering. Proper watering and adding necessary nutrients can prevent and correct these issues.

Watering Issues

Both overwatering and underwatering can cause mulberry leaf problems and root issues. Following a consistent watering schedule and ensuring proper drainage can prevent these issues.

Nutrient Deficiencies

Nutrient deficiencies may cause mulberry leaves to turn yellow. Regular soil testing (your local county extension office likely offers this at little to no cost) and fertilizing can address these deficiencies.

Disappointing Fruit

Poor fruiting may result from inadequate sunlight or poor pruning practices. Ensuring proper sunlight and timely pruning can address this issue.

Uneven Growth

Uneven growth might be due to poor soil conditions or diseases. Soil testing and addressing any disease or pests can correct uneven growth.

Incorrect pruning can also cause growth to be uneven, so trim wisely.

Damage to Trunk or Roots

Physical damage to the trunk or roots caused by lawn equipment, nearby construction, etc. can weaken the tree. Regular monitoring and good tree care practices can prevent this damage.

Toxic Sap

Some mulberry varieties may have toxic sap. Pruning cuts often excrete sap, so wear gloves, and avoid touching tree wounds.

Certain diseases, such as wetwood, can cause sap to leak from cuts weeks or even years after pruning. Careful handling and selecting the right variety can prevent issues related to toxic sap.

Conclusion

Growing mulberry trees offers delightful fruit and beautiful foliage, but it also requires vigilance against plant diseases and pests.

By recognizing the symptoms, implementing preventive measures, and applying appropriate treatments, you can enjoy a thriving mulberry tree.