slugs and snails eating potato plants

Slugs And Snails Eating Potato Plants: identification and removal

If you have noticed chew marks on the leaves of your potatoes in the morning but can’t identify the culprit, you may have a problem with slugs or snails. These garden pests come out under the cover of darkness and slip out of sight when morning arrives. Look for glistening trails on the foliage as both leaves behind a trail of slime. Otherwise, check the garden early in the morning before the dew dries or on rainy, wet days for signs of slugs and snails in the garden. Look in tall grass, under rocks, or other cool, dark spots around the garden.

What damage do slugs and snails do to potato plant leaves?

Snails and slugs are soft-bodied mollusks that often attack plants in the vegetable and flower garden. Although they are actually omnivores and feed on both vegetation and dead carrion, they often become a problem when they attack vegetables and flowers in the home garden.

Both slugs and snails are known to feed on potato plants (along with many other garden veggies). They eat the leaves and stems of the plant. With a severe slug infestation, they may strip your potato plants of all their leaves.

a potato plant with its top leaves eaten by slugs and snails
A potato plant with its uppermost leaves and stems eaten by slugs and snails – these were first to appear through the soil.


What will happen to my potato plant after the leaves are eaten?

Potato plants need leaves to perform photosynthesis and store energy in the potato tuber. Without leaves, the plant cannot form tubers and will soon die. If slugs and snails eat all the leaves off your potato plants, the plants will die.

However, if slugs and snails only eat a few leaves, the potato plant will produce new leaves and will soon revive once you have rid the garden of slugs and snails. As long as your potato plants have some healthy leaves, the plant is likely to revive and produce healthy new foliage to make the energy needed to form the tubers.

a potato plant with all its leaves eaten
All the leaves have been eaten on this potato plant – it may never recover enough to produce a decent crop of potatoes.


Where do the slugs hide during the day?

Slugs hide in moist, dark places, like under logs, rocks, or garden debris during the day when the sun is shining. But those aren’t their only hiding places. According to Oregon State University, slugs burrow into the soil to an incredible six feet deep. It is estimated that only about 5 percent of slugs are above ground at one time.


Where do the snails come from?

Snails hide in cool, dry places like under rocks, fallen leaves, and logs during the day and come out at night when the earth is cool and damp. They also come out on rainy days. You will most likely see snails in the early morning before the dew has dried on the grass.

Many snails hibernate in clusters under rocks, logs, or other debris during the winter, explains Backyard Pests. They go into hibernation when temperatures drop below 60 degrees. If the temperature drops below 23 degrees, the snails may die.  Hibernating snails ‘wake up’ in the spring when temperatures rise above 60 degrees.

Snails also lay eggs in the soil. The eggs generally overwinter in the soil, and tiny snails hatch out in the spring.


How do I stop slugs from eating my potato plants?

There are several methods for controlling slugs. The simplest method is to hand pick the slugs and drop them into a bucket of soapy water to kill them. This method is effective if you find an occasional slug in the garden but may be challenging with a more severe infestation of slugs. For more serious slug problems, try these methods.

  • A Saucer of Beer: Slugs love stale beer and will happily seek it out if you offer it in a saucer or pan in the garden. But be sure the saucer is sunken into the soil so the slug will fall in when he stops for a drink. The saucer should be deep enough that the slug cannot crawl back out once he has fallen in. The slug will drown in the beer.
  • Yeast & Honey: If you’d rather not use beer or don’t have any in the house, you can use a saucer of yeast and honey to attract slugs.
  1. Mix a few teaspoons of yeast and honey with warm water.
  2. Place a saucer in the soil, so the rim is at the soil level.
  3. Fill it with the yeast and honey mixture.
  4. Empty the saucer in the morning and discard the dead slugs.
  • Slug Bait: Slug bait containing iron phosphate is generally effective for getting rid of slugs. This bait comes in granules that are sprinkled on the soil around your plants. When the slugs (and snails) eat the bait, it upsets their stomach, and they stop feeding. They then crawl away and die within 3 to 6 days.

Iron phosphate is safe for birds, pets, wildlife, insects, and humans. It can be used safely around food crops and is effective for about two weeks. Watering the garden or natural rainfall does not decrease its effectiveness.

  • Metaldehyde: Metaldehyde works by dehydrating the slug but is only effective in dry conditions. If the snail reaches a moist area, its body will rehydrate. Likewise, the rain will prevent metaldehyde from working or dehydrating the slugs. It must be reapplied after rains. Metaldehyde is toxic to pets, wildlife, and humans and must be used with caution.


Can I prevent slugs from eating the potatoes under the soil?

If you have a severe slug problem preventing them from eating your potatoes in the soil can be a challenge. Because there is no way to know slugs are munching on your potato tubers until you dig them up, it is often too late to prevent further damage.

The best way to keep slugs from eating your potatoes in the soil is to keep the slug population under control during the spring and summer.

Harvesting your potatoes as soon as they mature, instead of letting them sit in the soil until you are ready to use them, may prevent issues with slugs eating your potatoes in the ground.


How do I stop snails from eating my potato plants?

a bird has eaten a snail and left its shell on the potato drills
A bird has caught this snail and eaten it – leaving behind only the shell.

Stopping snails from eating your potato plants is similar to stopping slugs. Both can be baited and trapped in a saucer with beer or a mixture of yeast and water. Bait, such as iron phosphate, attracts and kills both snails and slugs. Likewise, Metaldehyde can be used to kill snails, but it poses a greater risk to humans and pets. Birds are great for eating snails that haven’t made it to shelter.

For more details about killing slugs and snails in the garden, see the “How do I stop slugs from eating my potatoes?” section outlined above.

Summary

Slugs and snails eat the foliage of potato plants, and the slugs may even eat the tubers under the soil too. But they are relatively easy to control once you have identified the problem. Whether you try a home remedy or opt for commercial slug and snail bait is a personal choice. Always follow directions and observe all safety precautions when using slug and snail baits.

Links:

Garden Safe -Slug and Snail Bait – Can Be Used Around Pets and Wildlife

Monterey – Sluggo – Wildlife and Pet Safe Slug Killer 2.5lbs