Keep These 11 Pests Away From Your Potato Plants: Management Tips

Potato pests are unlikely, though they like to target weak plants. Start bolstering your potatoes’ defenses by keeping them well-fed, moisturized, and bright. Potatoes appreciate full sun, regular moisture, and plenty of nutrients.

Another thing to note is that most plant damage is from abiotic (non-living), not biotic (living) factors. First, ensure the plants have pests before treating them, as unnecessary treatments can cause more problems than they fix! Use caution, practice observance, and step in when necessary. 

The best way to bolster the crop is by regularly adding compost. Compost contains nutrients, microbes, and worms. When you add it to existing soils, the soil life from the compost seeps into the garden. It’ll help your potatoes resist pests, pathogens, and harsh environmental conditions.

Cover Crop Crimson Clover Seed Shaker

This annual clover has larger, elongated flower heads with deep red, long-lasting blossoms that invite beneficial insects, such as ladybugs and bees. Like other clovers, crimson clover fixes nitrogen, but it’s faster growing for quick benefits to your garden. Crimson clover grows best in cool weather, so grow it as a spring or fall cover crop.

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Colorado Potato Beetle

One of the most common potato pests, Colorado potato beetles have a few life stages that affect your crop’s growth. The adult beetles are orange-red with black stripes, and the wormy larvae are orange with black dots. The larvae and adults feed on leaves, stems, and flowers above ground.

Crop rotation is key to managing these beetles. Adults overwinter in the soil and emerge in spring to lay eggs on plants in the nightshade family Solanaceae. This includes eggplants, tomatoes, and peppers. Switch where you grow these crops every three years to prevent the beetles from building large populations. 

When Colorado potato beetles appear, the best thing to do is to handpick them off your plants. Plant vacuums make this a fun chore. Simply hover them around your plants and suck up the beetles. Put the beetles in a bucket of soapy water, then compost or bury them after they die. If they’re not present in the soil, you can use row covers in early spring to protect crops from the adults. 

Potato Leaf Hoppers

Leaf hoppers are tiny, sap-sucking insects that are harmful in large numbers. A few won’t harm your plants, though large populations can decimate crops. You’ll notice stippling, or spotting, on the leaves where they frequent. The tips of the leaves turn yellow and brown after long periods of infestation.

Leaf hoppers often attack mature plants as they’re forming tubers underground. Prevent them from arriving by using a row cover on your plants when the insects are abundant. A daily spray with a strong stream of water can help knock the adults off the leaves.

Most infestations in home gardens don’t require treatment, as these pests are more of a nuisance than a threat to your potato crop. Leave them be so that beneficial predators can come in and eat them; many other critters think leaf hoppers are tasty!

These hopping bugs may be problems indoors or in greenhouses. Treat extensive infestations with an insecticidal soap or organic horticultural oil like neem. Spray in the morning or afternoon to avoid harming pollinators that frequent greenhouse plants. Remove potato flowers before spraying to prevent beneficial insects from touching your plants after you spray. 

Flea Beetles

Flea beetles attack leaves, tubers, and roots as adults and larvae. The small, round black adult beetles feed on the foliage, creating small, round holes in infected leaves. The larvae are tiny white worms that can cause damage to the potatoes in large numbers. 

Prevention is best to keep this pest away from your potatoes. Remove weeds from garden beds in late winter and early spring to remove overwintering beetles. Using floating row covers prevents emerging adults from landing on your maturing plants. 

Treatment may be necessary if the young worms and adults are persistent. Spray organic treatments that target flea beetles, and follow the label on the bottle for proper instruction.  

Wireworms

Wireworms are wriggly larvae that target swelling potatoes underground. They’re white or red and may stay in the soil for three to seven years. They create tunnels in the tubers that invite rot and fungal infections. Though damaging, they’re not usually present in the home garden unless they were an issue in past years.

Practice crop rotation to discourage the worms’ presence in existing beds. Before treating, first test the site to see if they’re present. Dig a chunk of a potato in the soil with a flag sticking out a month before planting. Dig the trap up after 10 days and inspect the tuber to see if the worms are present. 

If they are present, consider growing your crops in a separate area where they aren’t abundant. Use raised beds, containers, or fabric grow bags while you wait three to seven years. Test the site each year, and wait to plant in that area until the worms are no longer there. 

European Corn Borer

European corn borers are ringed worms that are the larvae of a white, yellow, and brown moth. The borers tunnel into the stems and pupate, emerging in summer as adult moths. The moths lay eggs that hatch into larvae; the larvae then overwinter until the next year, when they emerge and start the cycle again.

These pests won’t often infect potatoes unless their populations are large and highly present in the region. They prefer corn, though they will target nearby potato plants when there’s a lot of them. Prevent their arrival with row cover to keep the moths from laying eggs. 

Once the borers tunnel into the stems, it is too late to treat them. Plant your crop in a new location for the next two or three years, and harvest tubers from wilted plants before they spoil in the ground. 

Blister Beetles

Blister beetles are long, slender, blackish beetles that look like giant ants. Some species have orange and black stripes, while others are all black or brown. They’re a complicated bug to treat, as their young are beneficial; the wormy larvae eat grasshopper eggs in agricultural fields!

Though these bugs aren’t often pests in the home garden, they can be a problem when the adults emerge during early to midsummer. They feed on the leaves and flowers, decimating growing plants. You’ll see a few of them and then a ton all at once.

If heavy infestations occur, consider using neem oil or insecticidal soap on the areas where the bugs are present. Spray in the morning or afternoon, and avoid spraying flowers that pollinators frequent. 

Aphids

Aphids are common pests of thousands of plant species, including potatoes! They’re small, soft-bodied insects with sap-sucking mouthpieces that puncture tender leaves. They’re harmless in small numbers, though they quickly reproduce and can take over after a few days of unchecked expansion. 

Aphids are hard to prevent because they’re tiny and incredibly common. Natural aphid predators are a great boon in the garden as they help keep pest populations to a minimum. Ladybugs, pirate bugs, and parasitic wasps are all helpful in the battle against harmful aphids.

If aphids do appear, try spraying them off the plants daily with a hose. After a week or two of daily spraying, the bugs should disappear. Don’t wait to hose them off, as they’ll quickly explode in population size after a few days. 

Potato Tuberworm

A gray moth lays eggs that hatch into potato tuberworms. The worms are larvae of the moth, and they attack swelling tubers while they mature. They use holes and cracks in the soil to enter tubers in the top two inches of the ground.

Prevent tuberworms from tunneling into the tubers by covering them with soil or compost as they form. Row cover helps prevent the moths from laying eggs in early spring. Always plant disease and pest-free seed stock from a reputable supplier.

Biological treatments use natural predators to your advantage. Nematodes are one such predator that is incredibly helpful in targeting the worms. Find a species like Hexamermis, Steinerma, or Heterorhabditis; they eat the tuberworms and aren’t harmful to your plants or the soil. 

Weevil

Weevils are nuisances! Both the adults and the grubs target tubers, buds, and foliage. These pests tunnel through potatoes, chew irregular holes in the leaves, and cause the potato plants to decline. They’re most active in southern states like California, Arizona, and Oklahoma from winter through early summer. 

Prevent weevil infestations by planting potatoes in the fall or winter in mild regions when they’re less active. The adults make notched marks in the leaves aboveground when they’re active at night. If you’re a night owl, you can inspect your potatoes at night and handpick the weevils off the leaves.

Adding beneficial nematodes to the garden can help keep weevil populations under control. This treatment option is the least harmful, as the beneficial predators turn weevils into organic matter for the soil. If you decide to use an organic pesticide, follow the label for proper instructions on how to use it. 

White Grub

White grubs are the larvae of May beetles. As their name suggests, the beetles emerge around May when temperatures are warming and the days are lengthening. Grubs are small and white when young and almost an inch long when mature. They have brown heads and three sets of legs. 

These grubs are particularly dangerous as they can feed on potatoes underground for many weeks before the foliage aboveground shows symptoms of decline. Crop rotation is the most effective control method as it prevents overwintering populations from building up inside the soil. 

Adults are rarely present on the foliage, and the issue is mainly the underground grubs. Practice crop rotation by planting beans, peas, or clover for three years before planting potatoes in the same spot. Plowing may expose the grubs to birds in areas where they frequent. 

Southern Mole Cricket

Mole crickets are fascinating insects! They look like crickets, except they have digging hands on their front legs like mole hands. They use these legs to dig in the soil and find suitable places for feeding, overwintering, and laying eggs. 

The eggs hatch into nymphs that are like mini versions of the adults, and the nymphs have six or more stages of molting before they turn into full-size adults. They’re common in warm southern states and rare in colder northern ones. 

Various flies, nematodes, and wasps are superb biological controls for southern mole crickets. Release them according to their instructions to ensure they find the crickets.