Strawberry plants are susceptible to a number of diseases caused by environmental stressors and pathogens. You should be able to identify strawberry diseases early and treat them before they become aggressive. You can also prevent various diseases by planting disease-resistant varieties, leaving enough space between each plant, and following the specific techniques below.
Step
Part 1 of 3: Identifying Strawberry Disease
Step 1. Observe leaves that are stunted and losing their luster
If the strawberry has slow growing, stunted, metallic, and dull bluish-green leaves, the plant is likely suffering from red stele root rot. To be sure, check the roots for rust-red or brownish discoloration before fruiting season arrives.
Step 2. Check for wilted plants, browned leaves, and blackened roots
If you see these signs, your strawberry plant is suffering from black root rot caused by a number of pathogens or poor environmental conditions.
Step 3. Detect spots early
If you see purple, brown, gray, rust brown, or white spots on your strawberry leaves, the plant is suffering from leaf spot. The color of the spots varies depending on local environmental conditions. This disease is caused by a fungus that likes moisture.
Step 4. Check if the fruit and flowers have black or gray moldy areas
Black or gray mold on strawberries indicates that the plant is suffering from fruit rot or flower blight. This fungus is caused by a fungus that gets on fruit and flowers by coming into contact with soil or with decaying material.
Step 5. Watch out for the fine white spots on the leaves and fruit of the strawberry
Powdery mildew is a disease caused by a fungus that can also cause strawberry leaves to curl and dry out.
Step 6. Watch out for purple spots
Very wet environmental conditions will invite the growth of fungi that can cause purple spot disease. This disease is known as leaf scorch.
Step 7. Watch for dry plants and wilted leaves
Verticillium wilt (verticillium wilt) is caused by a fungus that can attack very aggressively during the first year of strawberry growth. This disease can cause the oldest and outermost leaves to wither, dry, and turn reddish yellow to dark brown. The younger innermost leaves will remain green.
Part 2 of 3: Treating Diseases in Strawberry Plants
Step 1. Treat red rot root by improving drainage
Discolored roots indicate the presence of red rot root pathogens. This pathogen likes to live in wet soil. Wet soil is a sign that the strawberries don't have good drainage. Add a well-draining medium, such as compost or peat moss, to the soil in your garden.
- To treat pathogens in your home garden, use an organic fungicide such as Aliette WDG, and follow the directions for use. For commercial use, you must use commercial grade pesticides in accordance with the respective regional regulations.
- If you are forced to grow your strawberries in consistently wet soil, plant varieties that are resistant to red rot, such as Allstar, Sparkle, Sunrise, and Surecrop.
Step 2. Treat root black rot by improving soil quality
You can improve the environmental conditions that trigger black rot root disease by improving soil quality using organic matter, ensuring that the soil is well drained, and following proper watering and fertilizing practices based on the specifics of the strawberry variety you are growing.
- The use of pesticides to eradicate black rot is strictly regulated. So, if a plant is suffering from this disease due to a pathogen, it is better to take it and just throw it away.
- Burn all infected leaves to prevent the disease from spreading.
Step 3. Treat leaf spot by stimulating new growth or spraying a fungicide
Severely infected plants will most likely die, but you can save newly infected plants by weeding the strawberry beds after the fruiting season is over. Weeding will reduce disease progression and stimulate new, healthy growth.
You can also try treating the fungus with an organic fungicide such as Captan 50 WP and a copper compound. Be sure to follow the directions for use on the label
Step 4. Treat fruit rot or flower blight with chemicals
Apply chemical remedies to damaged plants to heal the damage caused by fruit rot or flower blight. Try a chemical remedy like potassium bicarbonate.
- Prevention is the best way to control this fungus. So make sure to space the plants properly, fertilize at the right time (depending on the type of strawberry you're planting), remove any dead clumps after fruiting season, and spread straw mulch under the plants to keep the fruit from touching the soil.
- Skin rot is a similar disease that causes areas of the fruit to turn gray or purple and have a hard texture. You can use Captan 50 WP to treat this type of fungus.
Step 5. Treat powdery mildew by spraying a fungicide
Remove infected tissue by weeding strawberry beds. Then, treat the plant with a fungicide such as JMS Stylet oil, Nova 40W, and Rally 40W once the plant begins to flower.
The best defense against powdery mildew is to plant strawberry varieties that are resistant to this disease
Step 6. Treat leaf scorch by allowing the soil to dry
The best way to treat this disease is to change the watering pattern and allow the soil to become drier. If this is not possible, you can treat the strawberries with an organic fungicide such as Captan 50 WP and a copper compound.
Step 7. Treat verticillium wilt by rotating the plant
Pathogens lodged in the soil from previous plants can cause disease. So, the best way of control is proper crop rotation method. Unfortunately, there are no easy and recommended soil or chemical treatments for treating verticillium.
Strawberries exposed to low nitrogen content seemed to be more resistant to this disease than plants exposed to high nitrogen content. So, one way to eradicate this disease is to use fertilizers with lower nitrogen content
Part 3 of 3: Preventing Strawberry Disease
Step 1. Rotate the plants
Many pathogens are transmitted by infected soil, surrounding fields, birds and wind. To reduce exposure to pathogens and keep the soil healthy, rotate the strawberry plant every few years.
Strawberries should not be planted in soil where tomatoes, potatoes, eggplant, peppers, or stone fruit were grown for the next 5 years because these plants can harbor diseases such as verticillium and red root rot in the soil
Step 2. Plant strawberry varieties that are suitable for your area
Certain strawberry varieties are better adapted to certain regions and climates. Visit your local plant store or nursery to talk to the experts about the best strawberries to grow in your area. Planting the best varieties according to the region will help eliminate diseases caused by environmental stresses.
Step 3. Choose a strawberry variety that is resistant to disease
The best way to prevent strawberry disease is to plant disease-resistant varieties. Research the internet about the most common diseases in your area, then choose varieties that are resistant to all or most of them.
Step 4. Plant disease-free strawberries
Never plant strawberries that appear to have signs of disease. Planting diseased strawberries will contaminate the soil and surrounding fields for years. Only grow healthy strawberries.
Step 5. Avoid the shade
Strawberry plants need 6–10 hours of direct sunlight per day. Sunlight will help the plant to grow as well as help fight disease by making the plant dry out quickly after heavy rains or heavy dew.
Step 6. Use mulch
Spreading mulch (such as straw, sawdust, husk, or leaves) around the strawberries will help kill disease because it protects the plant from dehydration and fluctuations in soil temperature.
Step 7. Don't stress the plant
Strawberry plants will be susceptible to disease when stressed. Stress on plants can arise if strawberries are planted in clay media or soil containing high salt content, the water content is too much or too little, the planting depth is not right, and the planting place is too shady.
As much as possible, follow the specific planting instructions according to the strawberry variety being grown
Step 8. Spread the strawberry vines
Strawberries don't like crowded conditions and crowded areas because these conditions can increase humidity levels and worsen drainage, which in turn will allow mold to thrive. Give the distance between plants according to the specifications of the variety.
Step 9. Remove any dead or rotting parts
Flowers or strawberries that touch dead or rotting parts will also rot. Remove dead leaves and fallen fruit from around the plant.
- The “rotting part” also includes organic matter present in the soil. Spread straw mulch under the plants to prevent the strawberries from coming into direct contact with the soil.
- Water and fertilize the plant according to the directions for the variety in question so that you get an abundance of strawberries.
Tips
- Prevent the spread of disease by sanitizing all gardening tools and gloves after you come into contact with infected plants.
- When using chemicals, protect yourself and your skin using appropriate protection, including long pants and long-sleeved shirts, goggles, and gloves.
- Limit chemical exposure to yourself and your family, including pets. Before spraying the chemical, remove pet food or water bowls from the area.
- Store all unused chemicals in their original containers and store in a cool, dry place.
