Pest & Disease Control for Strawberry Plants
Every plant has the future potential for disease and insect damage. Factors such as location and weather will play a part in which issues your plants encounters. If available, disease-resistant varieties are the best option for easy care; and for all types of plants, proper maintenance (such as watering, pruning, spraying, weeding, and cleanup) can help keep most insects and diseases at bay.
NOTE: This is part 7 in a series of 11 articles. For a complete background on how to grow strawberry plants, we recommend starting from the beginning.
Tarnished Plant Bug
Yellow-brown winged insect may have black spots or red stripes. Inject toxins into the buds and shoots that cause ‘dwarfed’ shoots and sunken areas (cat facing) on fruit.
Natural Control
- Safer® Brand Insect Killing Soap
- Monterey Fruit Tree Spray Plus
Chemical Control
- GardenTech® Sevin® Concentrate Bug Killer
Leafroller
Pale yellow or ‘dirty’ green worms. Leaves are rolled and webbed together where insects feed. Eventually becomes skeletonized.
Natural Control
- Hi-Yield® Vegetable & Ornamental Insect Control
Chemical Control
- GardenTech® Sevin® Concentrate Bug Killer
Strawberry Leaf Beetle
Adults are small beetle that feed on leaves making many small holes. Larvae feed on roots. Plow up bed in mid summer to kill the larvae. Replant with new plants in another bed.
Control
- Consult County Extension Agent
Crown Borer
White legless grub 1/5” long hollows out crown, plants slowly deteriorate and die.
Control
- Consult County Extension Agent
White Grubs
Large fleshy grubs eat roots of new plants, which slowly die. Don’t plant in areas that were recently grass.
Control
- Consult County Extension Agent
Spittlebug
Immature bugs are small green, soft-bodied and adults are small (1/4”) winged insect that feed on the plant sap. They are surround by a white mass that looks like spit.
They suck on the sap, weakening the plants.
Natural Control
- Monterey Fruit Tree Spray Plus
Chemical Control
- GardenTech® Sevin® Concentrate Bug Killer
- Monterey Fruit Tree Spray Plus
Weevil
Lays eggs in flower buds, and girdles the stem. Larvae feed on buds and destroy them.
Chemical Control
- Monterey Fruit Tree Spray Plus
- GardenTech® Sevin® Concentrate Bug Killer
Japanese Beetle
Adult is metallic green beetle. Skeletonizes leaves. Larvae are grubs which feeds on turf roots. Check turf product labels for timing of control of grubs. This is more of a problem east of the Mississippi River.
Chemical Control
- Monterey Fruit Tree Spray Plus
- GardenTech® Sevin® Concentrate Bug Killer
Aphids
They are the size of a pinhead and vary in color depending on the species. Cluster on stems and under leaves, sucking plant juices. Leaves then curl, thicken, yellow and die. Produce large amounts of a liquid waste called “honeydew”. Aphid sticky residue becomes growth media for sooty mold.
Natural Control
- Monterey Horticultural Oil
- Safer® Brand Insect Killing Soap
- Monterey Fruit Tree Spray Plus
Chemical Control
- Monterey Fruit Tree Spray Plus
- GardenTech® Sevin® Concentrate Bug Killer
Spider Mite
Not a spider, but a tiny mite, sucks the juices from the leaves causing them to develop yellow and reddish-brown spots. Leaves die and drop. Underside of leaf appears to be dusted with white powder.
Natural Control
- Monterey Horticultural Oil
- Safer® Brand Insect Killing Soap
- Monterey Fruit Tree Spray Plus
Chemical Control
- Monterey Fruit Tree Spray Plus
- GardenTech® Sevin® Concentrate Bug Killer
Fruit Rot
Gray, hairy mold. Decays blossoms, green and ripening fruits as well as harvested fruits.
Control
- Consult County Extension Agent
Leaf Spot
Purple spots on leaves, may or may not have gray centers. Can be round but also fan-shaped. Can cause leaf curl. Many fungi cause spots and affect different varieties differently.
Natural Control
- Monterey Liquid Copper Fungicide
- Monterey Fruit Tree Spray Plus
Chemical Control
- Monterey Fruit Tree Spray Plus
- Hi-Yield® Captan 50W Fungicide
Leaf Blight
Appears as large red to brown spots with purplish margins. Mostly on older fruiting plants.
Natural Control
- Monterey Liquid Copper Fungicide
- Monterey Fruit Tree Spray Plus
Downey Mildew
Usually appears on the underside of the leaves as tufts or downy masses of vegetative tissue leaves. Shoots and buds may be curled and whole plant somewhat dwarfed. Is more prevalent in humid weather.
Natural Control
- Monterey Liquid Copper Fungicide
Slugs
Soft bodied, looks like a snail with no shell. Burrows into ripening fruits.
Natural Control
- A proven method of control is to put aluminum pie pans out with 1” of beer they crawl in and drown. Be sure to empty daily.
Other Control Options
- Consult County Extension Agent
Red Stele
Plants wilt and die, usually just before or during harvest. Roots decay and show red cores. Control by rotating crops with at least 4 years between them. Most resistant variety is ‘Surecrop’.
Control
- Consult County Extension Agent
Mites
Pinpoint in size, many different colors. Found on undersides of leaves. Sap feeding causes bronzing of leaves. Severe infestations have some silken webbing.
Natural Control
- Monterey Fruit Tree Spray Plus
- Monterey Horticultural Oil
- Safer® Brand Insect Killing Soap
Chemical Control
- Monterey Fruit Tree Spray Plus
- GardenTech® Sevin® Concentrate Bug Killer
Leaf Scorch
Occur when leaf cells overheat, browning and tissue death around leaf margins and between veins.
Natural Control
- Monterey Liquid Copper Fungicide
Gray Mold
The fungus thrives in cool, moist conditions. Usually begins on plant debris, weak or inactive plant tissue, than invades healthy plant tissue. Causes spotting and decay of flowers and foliage, tissue becomes soft and watery. Affected parts of plant could wilt and collapse. If humidity remains high a grayish-brown coating and spores develops over the surface of the collapsed tissue.
Natural Control
- Good sanitation will help avoid the problem.
- Remove and destroy dead leaves, flowers and dead plants.
- Water the plants at soil level and not on foliage.
Chemical Control
- Hi-Yield® Captan 50W Fungicide
