Will Epsom Salt Kill Slugs? How to Use It as a Natural Pesticide

Slugs and snails can quickly destroy ornamental plants and edible crops in the garden. These slimy pests use rasping tongues to chew holes in foliage and feed on roots below ground. While chemical molluscicides are effective Epsom salt provides a natural control option. When used properly, this mineral can repel dehydrate, and kill slugs and snails.

What is Epsom Salt?

Epsom salt, also known as magnesium sulfate, is a mineral compound comprised of magnesium, sulfur, and oxygen. It dissolves readily in water and is commonly used in bath salts Epsom salt also has applications for pest control, plant nutrition, and other household uses.

The name comes from its discovery in the bitter saline springs located in Epsom, England. Epsom salt has been used for centuries as a natural remedy for various ailments. Inside the garden, it can deter slugs in two ways:

• The abrasive texture of salt crystals deters slugs upon contact, similar to table salt.

• Magnesium sulfate is hydrating and absorbs moisture which dehydrates and desiccates slugs.

When applied correctly around plants, Epsom salt provides an economical, non-toxic salt barrier that can stop slugs in their tracks.

Will Plain Epsom Salt Kill Slugs?

Yes, plain Epsom salt crystals will kill slugs through contact and dehydration. However, table salt or rock salt is usually more effective and affordable than Epsom salt.

The main advantages of Epsom salt are:

• Provides supplemental magnesium, an essential plant nutrient needed for photosynthesis.

• Improves the absorption of nitrogen and phosphorous.

• Decomposes and enriches soil over time unlike table salt.

Since Epsom salt releases beneficial minerals into the soil, it can be used around ornamental plants and in the vegetable garden. Table salt may damage plants when used heavily over time.

How to Apply Epsom Salt as aSlug Barrier

To create a protective barrier that repels slugs, follow these steps:

1. Water plants well before application

Well hydrated plants are less likely to absorb excess Epsom salt. Watering the day before creates a moisture buffer.

2. Sprinkle a Band around plants

Pour Epsom salt directly from the carton or use a shaker to apply a 3-6 inch wide band around susceptible plants. Focus on the drip line area where slugs travel and congregate.

Reapply every 1-2 weeks or after heavy rain or watering.

3. Mulch over the band

Cover the salt with a thin layer of mulch, compost, or soil to prevent runoff. This allows the Epsom salt to remain effective longer after irrigation.

4. Dispose of dead slugs

Pick up any slug carcasses and dispose of them away from the garden. Leaving them in place risks recontamination of crops.

Epsom Salt Spray for Direct Application

For direct application onto affected plants, create a salt spray by mixing 1-2 tablespoons Epsom salt per gallon of water. Add the salt first and stir until fully dissolved. Pour the solution into a spray bottle or pump sprayer and completely coat the leaves, stems, and surrounding soil surface where slug damage is visible.

Test spray a small area first to ensure the dilution is safe for the plants. Reapply the Epsom salt spray after rainfall washes it away. Combining cayenne pepper or garlic into the spray repels slugs through taste aversion on top of salt’s abrasive effects.

Always spray in the evening or early morning to avoid leaf burn. Never apply to plants that are heat or drought stressed.

Watering Can Method for Large Areas

For large gardens, flower beds, or row crops suffering extensive slug damage, Epsom salt can be diluted in water and generously applied using a watering can.

Fill a 2-5 gallon bucket halfway with hot water. Add 1/2 -1 cup Epsom salt and stir until fully dissolved. Top off the bucket with cool water and stir again. Use this salt solution to liberally drench affected areas. Reapply weekly or after heavy rain.

The Epsom salt gets taken up by the soil and leaves a protective zone around plant roots while also providing nutrients.

When to Apply Epsom Salt

• Spring – Early in the season when young seedlings and transplants are most vulnerable.

• Summer – During hot, humid weather when slug populations surge.

• Fall – To protect autumn crops like lettuce, kale, carrots, and cool season greens.

• After rain – Reapply salt after heavy rain or watering washes away the barrier.

• Evening – Best applied at sundown when slugs are active. Avoid watering at night.

• 1-2 week intervals – Reapply salt every 7-14 days for best results.

Where to Apply Epsom Salt

• Flower beds – All around the outer edges to block slug entry.

• Vegetable garden – Focus around seedlings, low-growing crops, and along garden perimeter.

• Potted plants – Sprinkle in a ring around the container rim where slugs crawl up.

• Hostas, lettuces, greens – Slug favorite crops need thorough protection.

• Damp areas – Target naturally moist parts of the landscape.

• Under boards – Slugs hide under debris; lift and sprinkle salt underneath.

Epsom Salt Rate for Slug Control

• Light infestation – Apply 0.5 lbs Epsom salt per 100 square feet.

• Moderate infestation – Use 1 lb Epsom salt per 100 square feet.

• Heavy infestation – Up to 2 lbs per 100 square feet may be needed.

• Ring around plants – Apply a band 2-4 inches wide around each plant.

• Container plants – 1/2 teaspoon per 4-6 inches of pot circumference.

Risks and Precautions When Using Epsom Salt

• Avoid excessive use on plants. Too much Epsom salt can build up in soil and cause nutrient imbalances over time.

• Keep salts away from young seedlings and salt-sensitive plants like beans, onions, and cabbage which may be damaged by over-application.

• Prevent runoff into bodies of water where excess magnesium can trigger algae blooms and imbalance ecosystems.

• Do not inhale Epsom salt dust. Wear a mask and dampen the area when applying.

• Wash hands after handling Epsom salt to prevent accidental eye irritation or ingestion.

Alternatives to Epsom Salt for Slug Control

• Diatomaceous earth (DE) – Natural abrasive dust that dehydrates slugs. Must be reapplied frequently.

• Crushed eggshells – Coarse, sharp texture repels slugs. Scatter around plants.

• Coffee grounds – Caffeine and aroma deter slugs. Spread around garden beds.

• Gravel, sand, cinders – Gritty substrates discourage slug travel and damage foliage when they crawl over them.

• Beer traps – Yeasty brew attracts then drowns slugs. Set containers level with soil.

• Slug predator insects – Beetles, fireflies, ground beetles eat slugs. Attract them naturally.

When applied properly, Epsom salt provides an affordable, non-toxic, and eco-friendly slug control option that doubles as a fertilizer. Along with cultural methods like removing debris, mulching, and encouraging predators, this mineral can help protect plants from slug devastation using natural means. Give Epsom salt a try to take back your garden from these bothersome pests!