Strawberry plants are one of the easiest fruit plants to add to your garden, but that doesn’t mean you won’t encounter common strawberry pests and diseases. Pests and diseases love strawberry plants as much as we do!
The first year I grew strawberries, I lost most of my harvest to a terrible aphids infestation. It turns out that dealing with strawberry pests and diseases was harder than I expected. I spent time learning about the common pests and diseases that infect strawberry plants and how to prevent them to the best of my abilities.
Here are some of the most prevalent strawberry pests and diseases.
8 Common Strawberry Pests
Strawberries are delicious! Everyone loves them, including insects. There are lots of pests out there just waiting to chomp on your strawberries. Here are the most common.
Aphids are one of the most common garden pests, so it’s not surprising that they’re one of the common strawberry pests, as well. These are small, soft-bodied insects that like to stick to the underside of leaves and stems, sucking out the sap from the plants. Then, they leave behind a sticky substance called honeydew that attracts other pests and diseases.
Small infestations rarely cause serious problems, but severe infestations can destroy entire crops. Be sure to take a look at our guide to getting rid of aphids in your garden.
Armyworms are a destructive garden pest that causes closely grouped irregularly shaped holes on the leaves of the plants. If heavy feeding happens, you’ll end up with skeletonized leaves and dry wounds on the pests. Armyworms also leave egg clusters on the leaves; these pests produce 3-5 generations per year.
Organic control methods work for armyworms like releasing natural enemies or applying Bacillus thuringiensis. Take a look at our guide for armyworms in the garden.
3. Japanese Beetle
Japanese beetles are easy to spot; they have a green-copper metallic color and measure 13mm in length. Adult Japanese beetles skeletonize leaves and cause flower damage. If left alone, these pests will cause extensive plant damage.
Using floating row covers is a great way to protect your plants from these pests, and if you spot the adult beetles, you can hand pick them off the plants and stick them in soapy water. Releasing parasitic nematodes also reduces the number of Japanese beetles overwintering in the soil.
If you’re struggling with Japanese beetles, consider spraying your plants with neem oil or insecticidal soaps. These reduce beetle populations.
Another one of the most common strawberry pests is loopers. These pests leave behind large and/or small holes, causing extensive damage. Loopers are pale green caterpillars that have white or cream lines running down either side of their body. They usually stick to the lower leaves of the plants.
The best way to keep looper populations in check is by encouraging and releasing natural enemies in your garden. Gardeners may also hand-pick loopers from the plants.
If these methods aren’t working for you, consider applying Bacillus thuringiensis, which will kill the larvae. Avoid using chemical sprays because they also kill off the natural and beneficial insects in your garden.
Everyone knows what slugs look like, but you might not know that these pests cause irregularly shaped holes in the leaves and stems of the plant. Slugs also eat holes in the ripening fruit, and during severe infestations, slugs might shred the leaves.
Removing garden trash, weeds, and debris help to reduce slugs because it takes away their hiding places. At night, handpick slugs off of your plants and spread eggshells around the plants to discourage these pests.
Take a look at all the ways you can get rid of slugs in your garden.
6. Strawberry Spider Mites
Strawberry spider mites and other species of spider mites are some of the most frustrating strawberry pests; they’re so small that they’re hard to control. A spider mite infestation causes yellow stippled leaves and bronzed leaves. They might also have webbing-covered leaves, and if you look closely, you might see mites moving on the webs or the underside of the leaves.
Spraying the plants with a strong jet of water is one way to reduce the spider mite population in your garden. Insecticidal soaps also can decrease population, along with different insecticides. Look to see if the insecticides you buy are useful against spider mites.
Thrips cause damage to flowers on strawberry plants, causing the browning of anthers and stigmas. These insects are small; it’s easiest to see them if you have a magnifying glass. Adult thrips are pale yellow to light brown, and the nymph stages are smaller and lighter in color.
Thrips appear the most in the spring, appearing on weeds and crops like strawberries. Using reflective mulches is one of the best ways to deter thrips. You also can use appropriate insecticides if they become problematic.
Weevils cause notches in the leaves of your plants, along with stunted growth and closely bunched leaves. This pest varies in color from dark to light brown, and the larvae are cream to white-colored grubs that feed on the roots.
Keeping your strawberry beds free of weeds is an important step to keeping weevils out of your garden. Don’t plant them too close to blackberries or elderberries which tend to have more weevils. Pesticides that contain pyrethroids are effective at controlling these populations.
5 Common Strawberry Diseases
These common diseases cause true problems for your plants, and severe infections can lead to the death of your strawberries, so make sure you learn about preventative measures to take in your garden. That means cleaning up your garden, as well as appropriate spacing, watering, and fertilizing.
1. Angular Leaf Spot
Angular leaf spot is a bacterial disease that causes small, water-soaked lesions to form on the lower surfaces of the leaves on your strawberry plants. Over time, the lesions enlarge and turn dark green, eventually oozing.
This bacterium survives in the debris of your crops and overwinters on the plants. It survives for long periods on the debris, but it won’t live in the soil. If you water your plants above, the bacteria spread through the splashing water on the leaves.
Unfortunately, getting rid of angular leaf spot is difficult, if not impossible. It’s smart only to plant certified disease-free stock and to rotate your crops. Using any form of chemical control will be totally ineffective against this bacterial disease.
Anthracnose is a fungal disease that causes round black or light gray lesions on leaves, but the foliage may not die. It also causes dark brown or black, circular lesions on the stems. This disease causes a range of signs and symptoms; take a look at our anthracnose guide.
While anthracnose is one of the most common strawberry diseases, it’s also hard to control. Solarizing the soil is one of the best options, as well as weeding plants regularly.
3. Gray Mold
Gray mold is a common fungal disease that causes strawberry blossoms to turn brown and die. It also causes misshapen and rotting patches on the fruit. You’ll find masses of gray mycelium on the rotting tissue, and eventually, the fruit becomes dried and mummified.
Gray mold emerges after periods of high humidity and moisture. Controlling the weather is impossible, though you can control, the environment. Water at the soil level and keep plants well spaced.
You have to remove and destroy all dead or infected material and toss any decaying fruits. Applying fungicides is a good measure against it, but there is no guarantee they’ll work.
4. Leaf Scorch
Here is a fungal disease that causes irregular dark purple or brown blotches on the upper leaf surfaces. Over time, leaf scorch causes larger purplish-brown patches, and the tissue between the blotches might turn purple or red.
Leaf scorch causes lesions on the flowers and fruits as well. It happens most often when the foliage stays wet for a long time. It might cause petals to wither and drop off the plant, and it causes the death of the fruits.
Ensuring your strawberry plants also have good air circulation and soil drainage is essential. Applying foliar fungicide may provide enough control in this situation.
5. Powdery Mildew
Powdery mildew is one of the most common fungal diseases that you’ll find throughout your garden. It causes patches of fuzzy white fungal growth on the lower leaf surfaces that eventually enlarge, and you might find purple-red blotches on the lower leaf surfaces.
If powdery mildew takes over your plants in a severe form, your plants might produce no fruits at all.
The spores overwinter on leaves and spread easily by the wind. You can try applying a protection fungicide at the first signs of the disease. It’s one of the most effective measures.
You can learn more about powdery mildew in the garden by reading our guide.