Not many crops please quite like strawberries (Fragaria × ananassa) ripened by the sun and enjoyed freshly picked, when they are at their sweetest, from your own backyard. People aren’t the only beings attracted to the juicy fruits, however. Several pests and fungal pathogens will find their way into the garden as well. You’ll save yourself a lot of work and some heartache by choosing disease-resistant varieties, that is those that are adapted to growing in your region and purchased from a reputable nursery. Preventive sprays are also available. Strawberries are hardy to U.S. Department of Agriculture plant hardiness zones 3 through 10, depending on variety.
What Bugs Strawberries?
Like most plants, strawberries are attractive to an assortment of pests. Among them, two species of spider mites, the two-spotted (Tetranychus urticae) and the carmine spider mite (Tetranychus cinnabarinus) show up early in the season. The strawberry weevil (Anthonomus signatus) and strawberry aphid (Chaetosiphon fragaefolli) appear around the same time. After the strawberry blooms, be on the lookout for potato leafhoppers (Empoasca fabae) and strawberry leafrollers (Ancylis comptana).
Common Strawberry Ailments
One of the most common diseases of strawberry plants is Phomopsis leaf blight, which is caused by the fungus, Phomopsis obscurans. Symptoms include circular spots with a red-tinted halo. The spots become irregular and then “V” shaped as the disease progresses. This same fungus causes another disease, fruit rot, in warm climates. Strawberry leaf spot is another common disease, caused by Mycosphaerella fragariae, another fungus. Symptoms are similar to those of leaf blight, but the lesions lack the red halo.
Fungicide Spray Schedule
Treat the strawberries before they bloom when you can see the buds in the crown. Use a fungicide spray that contains both malathion and captan at a rate of 2.5 teaspoons in 1 gallon of water. Spray the strawberry plants completely, including the undersides of the foliage. In the early bloom period, switch to a product containing just captan and apply 2 tablespoons in 1 gallon of water until the strawberry plants are drenched. Ten days after the strawberries bloom, reapply the malathion/captan product at the same rate you used the first time and reapply every week until harvest is finished. Although strawberries may be eaten the day they are sprayed with captan, wear protective gloves while harvesting the berries for the first four days after spraying.
When to Spray Insecticides
Spray for insects only if they are present at the same time you spray the fungicide. A strong blast of water from the hose typically takes care of aphid infestations. Rosemary oil spray takes care of spider mites, but the spray must cover each pest. Use a pesticide containing carbaryl for other pests. Mix 3 ounces of the pesticide in 1 gallon of water and spray all surfaces of the strawberry plant. Early morning applications are most effective. Discontinue the use of pesticides when the plants bloom.
- Old Farmer’s Almanac: Strawberries
- University of California Statewide Integrated Pest Management Program: Strawberries
- Ontario Ministry of Agriculture Food and Rural Affairs: Potato Leafhopper
- Virginia Tech: Strawberry Leafrollers
- The Ohio State University Extension: Phomopsis Leaf Blight and Fruit Rot of Strawberry
- Michigan State University Extension – Oakland County: Spray Schedules for Pest Control on Strawberries
- University of Georgia: Home Orchard
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