Blackberry Diseases, Pests and Other Problems

Blackberries are prone to leaf and fruit diseases
Blackberry diseases and pests identification

How to care for blackberries in your garden

Blackberry plantings can be productive for over 40 years, depending on environmental conditions, disease control and the type of soil. When planting, carefully select an area with a great environment. Choose full sunlight and fertile soil with moderate water-holding capacity.

You must amend native soil with compost to increase its water-holding capacity. Blackberry plants are tolerant of wet, heavy soils and usually can grow without being planted in raised beds. Growing blackberries in containers is an option, so that conditions can be locally controlled.

Blackberry bush care

There are factors to consider when planting trees like the amount of shade and wind. If a tree is planted in an area with too much wind, the risk of freeze injury can be increased.

Remove any annual and perennial weeds before planting because it is hard to control them after planting. Make sure there are no seeds left on the ground and remove any plants with seeds.

Video – Pest & Disease Identification on Blackberry Plants

What’s wrong with my blackberry bushes? How to identify Blackberry diseases and pests

Blackberry cane diseases

Problem: Purple Blotch – What is blotch disease?

Affected Area: The disease affects the branches

Small dark green sores appear near the ground at first. As it spread the disease gets worse. The first sign of the contagious disease is red sores that turn brown and grow as it spreads up the plant. The inedible fungus will leave spots on leaves where the fungus has eaten them away and have outbreaks that go all way up to a plant’s branches

To avoid blackberry bush disease, make sure your fruit trees are healthy and have not grown up in the plant around it. Also make sure that branches that have this disease are cut off and burned. It has also been shown that spraying is effective.

Problem: Botryosphaeria Cane Canker of Blackberry

Affected Area: The disease affects the branches

Sores are red/brown discolorations that appear and most often form at any places where the branch had been injured. Impaired leaves in an infected part will begin to wilt, while it produces less fruit if any at all. If the sores progress and split the branch open, they are risking a loss of the entire plant.

Use disease free plants from nurseries to start berry patches, and fertilize the new plants well. Some plants are more resistant than others- be careful not to use too much nitrogen though.

Problem: Blackberry Rosette Double Blossom Disease

Affected Area: buds

Buds are usually infected in the summer and will showed signs of infection the following spring. Furthermore, small leafy branches come from each of the buds and they’re lighter in color than when they are healthy. The flower buds will be longer and redder than usual, with a twisted appearance. If there is any fruit present, it is poor-quality or nonexistent.

For new berry patches, you should use plants from a nursery to help prevent the spread of a fungus. It might be wise to plant the new bushes away from any old ones. If there are buds or shoots on them, they can be hand picked to make sure they don’t get infected. Also, without any branches that might be carrying the disease in them, it’s easier to control its spread.

Blackberry leaf disease

Problem: Downy Mildew

Downy fungus disease affects leaves
Downy Mildew on a Blackberry leaf

Affected Area: leaves

When leaves are infected with the disease, they turn yellow at first and then progress to have a red or purple color. There are light pink or brown spots on the bottom of the leaf and around the upper part of the surface.

What are the brown spots on my blackberries?

As it continues moving in, the spots go dark and appear yellowed at the edge. The leaves may fall off early and one symptom is that the fruit appears more dull than shiny.

A plant that is chemical-free and has never had a disease should be used to create a new patch, in places that have previously never had the disease. Using suckers to reduce the chance of having the disease introduced, while reducing moisture in these patches.

Old branches should also be removed. Spraying these patches with fungicides helps control the fungus causing some diseases.

Problem: Powdery Mildew

Affected Area: Entire Plant

Disease leaves infected have spots on the top; some of these spots are light green and others are white. The leaves will also appear to be wet for some time, eventually becoming long and twisted. These signs can also be seen in fruit that becomes covered in a white fungus.

Some types of berries are more resistant to the virus than others. To prevent infection, remove all suckers which show signs of disease. Cutting the plant back in spring also reduces chance of becoming infected. Sending in appropriate fungecides can also control fungus.

Problem: Septoria Leaf Spot of Blackberry

Affected Area: The disease affects the leaves

The infected leaves will develop white spots with a brown border. The disease can cause the leaves to fall off early.

Control the fungus by making sure plants have circulation, cutting off old branches, and using right fungicides.

Problem: Botrytis Fruit Rot

Affected Area: The disease affects the entire plant

The black spots show symptoms by the appearance of the flowers. The disease attacks the flower once it is open and begins to rot. The fruit may begin to rot in different areas on the fruit, but often starts near the stalk. If not removed, the fruit will have a gray mold come up on it and get stuck to the tree.

Fungicide for blackberries

Fungicides should be used as a main source of control because they dry out the areas around the plants and create pathways for good air flow. Good pruning techniques will also help to remove any disease that might have been transferred from the old brambles. Knowing when to pick-produce is beneficial in fighting mold, so raspberry picking should occur before the berries become overripe.

Problem: Postharvest Soft Rot

Affected Area: The disease affects the entire fruit

The disease only directly effects mature or damaged fruit, most often in storage. When this occurs, the berries will become soggy and fungus will grow on the outside of it.

This plant disease cannot, with any certainty, be cured. It’s important to maintain the plants by keeping them from staying wet, and picking the fruit at precisely the right moment. These methods work until we find a better way to treat this ailment.

Blackberry cane blight – Blackberry rust

Problem: Stamen Blight

Affected Area: The disease affects the flowers.

Flowers infected with a fungus have a white powdery appearance that can be observed as they lay down and decrease the size of the other healthy flowers.

How do you treat blackberry blight?

The diseased flowers create fruit that binds to branches and is damaged when removed. Care should be taken to use disease-free plants when starting berry patches. This can be achieved through fungicides.

Problem: Orange Rust

Affected Area: The disease affects the leaves of your plants

The disease can be detected very early, as the new growth will be clustered in twisted bunches. Leaves are usually odd shapes. Leaf tissue becomes speckled white with black specks that soon turn into blister-like bubbles. These eventually rupture and turn bright orange.

You should plant good, healthy plants and remove any wild plants. Removing any plants that show signs of rust in the spring will help minimize the damage later on. You should also look through your plants to locate leaves that have blister-like bubbles. Good air circulation is important, as well. Fungicides may be useful in controlling this disease.

Problem: Cane and Leaf Rust

Affected Area: The disease affects the branches and leaves

One symptom of this disease is yellow material that builds up on the outside of the branch and splits the bark. As this disease continues to get worse, the leaves of plants may begin to fall off early. This disease rarely affects the fruit.

To control the disease, make sure you remove old branches and use fungicides.

Problem: Yellow Rust

Affected Area: entire plant

The fungus is seen as orange material building up on the surface of leaves and shoots near the ground. It can also be seen as patches of yellow on buds and fruit. Infected branches can split and break.

Some raspberry plants have resistance to the fungus, so they can be used in areas where that disease occurs. The most effective way to stop spread of the fungus is by increasing air circulation and removing dead branches.

Problem: Late Leaf Rust

Affected Area: The disease affects the leaves and fruit

Leaf damage from spots turning from yellow to brown leads to leaves falling early and damaged branches. Yellow spots on fruit turn the fruit unusable for sale.

To achieve control of black leaf spot, increase the airflow to dry plants faster and remove dead leaves and branches in the fall. Adding fungicides can also be helpful but there is not much evidence to support their use.

Problem: Blackberry Rust

Affected Area: The disease affects the entire plant

The rust can afflict the entire plant and is most noticeable on the leaves. Yellowish/red patches appear on the tops of the leaves. In a few days the patches turn into round purple or red spots. These spots will then develop yellow or brown centers. Rusty patches form on the bottom of the leaf that are very powdery, even leading to some leaves turning white and falling off from branches in some cases.

Maximizing airflow and with appropriate fungicides are methods to control disease.

Problem: Phytophthora Root Rot

Affected Area: The disease affects the branches

The disease often strikes at the lower points in the field and branches quickly wilt and die in the spring. Sometimes the disease moves more slowly with branches slowly turning white and wilting during summer. Occasionally, the disease doesn’t become present until the next year.

Plants that are resistant to the disease should be planted, as well. You can also use good drainage and fungicides to eliminate the fungus.

Problem: Verticillium Wilt

Affected Area: The disease affects the leaves and branches

The disease turns the leaves a paler color in the summer and they are better in the fall. The following spring they turn yellow and then die. The branches will turn completely blue on one side before they die. With blackberries, the branches don’t turn blue but they cause everything to collapse.

There are pesticides you can use to control the disease as well as different techniques that include rotating crops and using fungicides.

Problem: Armillaria Root Rot

Affected Area: The disease affects the roots

As the leaves die and decompose, large amounts of carbohydrates are left in the soil. This can lead to a “mycorrhizal” fungi outbreak. The roots and crown of the plant can also be killed when these fungi attack.

How do you treat blackberry plant fungus?

A thick white, yellowish fuzz can appear on the surface of the roots and drive out what’s left of their chlorophyll (giving them a white or yellow appearance). This can easily be mistaken for tree bark or roots. In the fall, this mold appears all around the base of the plant and is recognizable by its appearance as ‘roots’.

To control the fungus, remove all infected plants and roots (including the ground) and then treat affected areas with a safe substance.

Some reasons for blackberries drying up on vine

Problem: Fire Blight

Affected Area: The disease affects the branches and leaves

The infection usually presents at the tip of the branch, then moves downward. This can cause the tree to die as it surrounds and causes wounds on the branches that have sticky liquid seeping from them.

Treatment: There is not one particular treatment that helps control this condition easily. Plant removal and increased air circulation are recommended to reduce the amount of diseased tissue.

Problem: Rubus Stunt

Affected Area: The disease affects the branches and leaves

The leaves have spots and many shoots break off. The plants usually show symptoms in a year.

To control pest infestation, plant good healthy plants that will deter the insects and their eggs. Using insecticide to kill those eggs will help control them.

Problem: European Nepovirus Diseases

Affected Area: The disease affects the leaves and growth

Tomato plant leaves develop yellow specks and yellow veins, as well as becoming a little distorted and wilting. The tomato plant growth may stop or slow down considerably- producing little or no fruit.

Plants must be healthy and free of viruses in order to minimize the chance of being affected by nematodes. Fumigants can often be used to kill the nematodes, but controlling weeds or rotating crops also prevents this problem.

Problem: Tomato Ringspot

Affected Area: The disease affects the leaves

The plant’s leaves will be delayed, which will result in fewer fruits. This can make the fruit yield less successful.

To start, test if the soil you are using is free of nematodes. Then use fumigants to stop them from proliferating. Secondly, control the weeds in order to limit erosion and promote plant growth.

Problem: Blackberry Calico

Affected Area: The disease affects the leaves

Various problems with leaves happen, from small yellow spots to more severe yellow rings and lines. Even if the disease is not too bad, it may damage the color of the leaves.

In most cases, growers don’t pay attention to botrytis since it doesn’t do much damage in large areas and is very sporadic. Heat treating the plants for long periods has been shown to eliminate the disease.

Problem: Tobacco Streak

Affected Area: The disease affects the leaves

The symptoms of a diseased plant are small, dead white rings that appear on new leaves as well as the tips of new branches.

To avoid the virus, plant a new raspberry plant next to an uninfected plant rather than mixing them. Planting a new raspberry near old plants with the disease will not help and the virus can still easily spread from the infected plant.

Blackberry pests pictures

Problem: Root-Lesion Nematodes

Affected Area: roots

Nematodes are worms that attack the roots of plants. The main symptoms could include smaller produce, slower growth, and a decrease in number of fruit produced by the plant.

Nematodes are only found in plants, so before planting anything, make sure to clean the ground with a fumigant. After planting, you can use chemicals to kill nematodes.

Problem: Dagger and Needle Nematodes

Affected Area: The damage affects he roots.

The roots of the wormwood become damaged when round bumps appear on the surface. Additionally, swelling occurs along with curled ends. Since the roots of the wormwood affect the growth of branches and fruits, these symptoms result in a crumbly product.

Planting plants that are resistant to nematodes is the best measure to take. Spraying the ground with insecticide before planting is also a good idea.

Problem: Strawberry Crown Moth

Affected Area: The damage is done to the roots and crown.

The moth larvae feed on the roots and crown of the plant, which injures the plant by causing it to grow slowly and turn yellow. The leaves also fall off prematurely.

To avoid infestation, remove any infected plants and any infested plants near them. You can also plant trap plants to attract, kill and destroy the moths as well. Insecticides have also been proven to be effective at combating the problem.

Problem: Japanese Beetle

Japanese Bettle affects the whole plant
Called Strawberry Japanese Beetle, but it also attacks blackberries

Affected Area: The damage affects the roots, leaves, and fruit.

The larvae will feed on the roots of plants and cause damage in those areas. The adults, on the other, feeds on the leaves and fruit. This does considerable damage to plants or is harmful for them.

The Control: Insecticides to kill bugs

Problem: Rose Chafer

Affected Area: flowers, leaves, and fruit

Description: The insects are most noticeable in soils with a lot of sand because they reproduce extremely rapidly. They attack domestic flowers, often cutting off the supply of produce, let alone the flower itself. With leaves and fruit becoming damaged as well, the negative effects of these insects are far reaching.

One way to make sure your garden is free of pests is to apply insecticides on it weekly, tilling the ground and turning it over regularly after heavy rains.

Problem: Lygus Bugs

Affected Area: The damage affects the flowers, branches, and fruits

This bug feeds on flowers, developing fruit, and tips of new shoots. It can destroy flower shoots, or cause shoot branching. Flowers killed can reduce fruit yield considerably, while fruit attacks can reduce yield as well.

Weeding and using insecticides should control the insects.

Problem: Picnic Beetles

Affected Area: Fruit

Beetles will bore into ripe fruit, especially if it is a little bit overripe. The beetles will eat part of the fruit and then leave the fruit looking bad. Often, the beetles also produce wastes that quickly make the rest of the fruit rot.

To control the insects that damage the fruit, make sure no overripe fruit is around and also remove any damaged fruit that may accumulate in the fields. After harvesting the berries, remove them from the field as soon as possible to cover and protect them.

Problem: Climbing Cutworms

Affected Area: The damage affects the new growth and fruit.

Larvae climb up new shoots and eat the tissue in the buds, leaving an entire plant with few leaves. The larvae get blown off plants during harvest, contaminates and spoils the fruit.

In order to control these fruit-eating worms, it is advised to apply insecticides after dark, when the worms are most active. The harvested berries should be checked for worms and then killed.

Problem: Blackberry Psyllid

Affected Area: The damage affects the entire plant.

This condition, also known as Gibberella blight, can severely damage plants if it is left untreated. The plant may stop growing and become distorted, with curled leaves and a lack of normal color. Sometimes the fruit on the plant will also be affected by this condition.

In order to control the insect, you need to use an insecticide and remove any infected branches that are near conifers.

Problem: Western Winter Moth

Affected Area: The damage affects the buds and blossoms.

The larvae of the moth feed on newly flowering plants in the spring, and may web their leaves together with silk before feeding.

Garden maintenance: Controlling larvae with insecticides

Problem: Rednecked Cane Borer

Affected Area: branches

The insect is found living on the inside of tree branches and prevents the branch from supporting its weight when fruit becomes ripe. The branches are easily damaged in the winter.

Control of the insect is usually done during winter pruning. Insecticides should be applied during the first bloom in the spring at the base of branches because as flowers grow, insects can affect them. Honeybees will die if they come in contact with the insecticide.

Thornless blackberry diseases

Problem: Low-Temperature Injury

Affected Area: Affects the entire plant

Description: If a plant is iced over in the winter, the buds and branches may suffer damage. If temperatures fluctuate in the spring or summer (from extreme cold to extreme hot), the buds could be killed and new shoots would stop growing. Low temperatures in this time can also cause damage to fruit which may get fungus as a result.

When the temperature changes, berry plants can suffer. Planting them in the spring, and covering them when it gets cold can help.

Problem: High-Temperature Injury

Affected Area: Affects the entire plant

Heat can kill plants, as well as make them grow too early. It can also cause droughts, which will kill the plants.

Control the watering and make sure to pick out the ripened fruit.

Problem: Wind

Affected Area: Affects the branches of the plant

Plant care needs include water, fertilizer and pruning. If branches rub against each other, cuts are created and the likelihood of infection or limb damage increase.

Planting a suitable windbreak for your garden can provide the stability needed in order to protect the plants.

Problem: Earwigs

Affected Area: Leaves

The reddish-brown, elongated earwigs reach up to 1″ in length and have pincers that grow up to ¼” long. They are nocturnal, hiding during the day and coming out at night. Earwigs live off decaying materials, but also enjoy eating fruit and blossoms.

Control: Yard cleanliness. Remove surface debris which provides shelter. Spray with *Sevin or *Malathion. Remember to check with your County for current recommendations for pesticides.

Problem: Grasshoppers

Affected Area: Leaves

Grasshoppers are robust insects with a voracious appetite. They generally lay eggs which hatch in the springtime if there is not a lot of disturbance in the soil. If disturbed, they may develop wings on adulthood and come into your garden to eat up leaves, fruits and vegetables.

Cultural controls are important to limit grasshoppers. According to the article, the most effective way of reducing infestations is by tilling or mowing and then spraying in areas of dry grass, along fences, in ornamentals and weed patches. This can be effective during the fall just after harvest when eggs are present and also during early spring. When it comes to chemical treatments Diazinon is best for hatching and small insects but Malathion is better for large infestations with its short residual effect.

Problem: Cane Borers

Affected Area: Stem

Description: When a cane dies back in midsummer, bees often hollow out the stem to manage the population of internal predators.

Spray with *sevin (Never spray blooming plants). When using a pesticide, make sure to avoid blooming plants and check back with your county agent for new recommendations.

Problem: Powdery Mildew

Affected Area: Leaves

Description: White powdery substance on leaves.

Wet leaves can cause disease, so you should use either surface or underground watering. The County agent will keep you informed as to the latest pesticide recommendations when there is a change in regulations.

Problem: Virus Diseases

Affected Area: Leaves

Description: Plants start to die, leaves yellow and curl.

Get rid of affected plants.

Common blackberry diseases PDF

FAQ for Blackberry diseases:

What diseases do blackberries get?

Blackberries are very delicate and can get many diseases. Below are some of the common diseases that blackberries could easily get:

Orange Felt: The yellow spots on blackberry are symptoms of this disease.

Cane Blight: The canes that are infected are silvery grey, these have large pruning cuts, or you may say wounds in them.

Leaf Spots: The symptom of this disease is fungi spots on leaves.

What’s wrong with my blackberry bushes?

Some pests include mites, thrips, and raspberry fruitworm beetles. These pests can cause fruiting problems in plants. You must check the bushes carefully and especially at the undersides of leaves. They can get insect attacks. So, keep on checking them.

How do you protect blackberries from pests?

You can go for the treatment options for blackberry bushes. Below are some of the best options:

Hand-picking and squishing these pests, or putting them in a soapy water bucket, is an effective technique to get rid of them.

Leaf-footed bugs can be deterred by companion planting.

Another effective preventative measure is to remove unwanted weeds and grass from garden areas, as these can attract them.

What can I spray on my blackberry bush for bugs?

If your plants are infected, you must try a spray. Make an apple cider vinegar spray, or you can also spray cayenne pepper all over your garden to add some heat. There are many ultrasonic repellers as well that you may install on the ground to scare them away. If everything else that you do fails, you can set up a live animal cage trap.

Why are there bugs in my blackberries?

Worms are found in almost all fresh blackberries. These worms are usually the larvae of Drosophila suzukii, fruit flies, or spotted wing drosophila. Fortunately, they are safe to consume.

When should you spray blackberries?

Blackberry plants that are intruding and need to be managed should only be sprayed after they have blossomed and there is adequate soil moisture. Spraying too early usually results in poor control and plant regrowth. The new wood must have fully emerged before blackberries could be effectively controlled.

How do you keep blackberries from getting worms?

Fruit should be picked before it becomes overripe and stored in the refrigerator. We’ve also noticed that putting the berries in salty water would help the worms emerge and float to the surface.

What is the fastest way to get rid of blackberry bushes?

The fastest best ways to get rid of warms are:

  1. Pulling
  2. Burning
  3. Mowing
  4. Herbicide
  5. Goats can help
  6. Covering them
  7. Cutting The Entire Bush

How do you use Roundup on blackberries?

Spray the weeds or bushes you want to destroy until they’re completely covered with water. Cut vines to 3 to 4 feet and spray vines completely if they are growing up the fences, poles, or trunks of trees that have matured bark. Cut vines at the base and spray regrowth by climbing tree trunks or shrubs having green bark.

Other resources relating to Blackberry Diseases and Pests

Blackberry | Diseases and Pests, Description, Uses, Propagation

Blackberries Part 2-Diseases | Piedmont Master Gardeners

Blackberry, Dewberry, and Boysenberry – Texas Plant 


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