What is the best slug killer in the UK? (2024)

What is the best slug killer in the UK? (2024)

Slugs are a common cause for severe plant damage. Nemaslug®  2.0 is a natural biological slug killer for the control of slugs. It can be used to kill all types of slugs in your garden. It controls all of the most common species of small and medium-sized slugs which damage garden plants.  
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It can be devastating to find plants in your garden that have been attacked and eaten by something. Slugs are a common cause for severe plant damage. Before deciding what to do, it’s important to correctly identify what has caused the damage. Slug feeding can be identified by:

  • Irregular large holes with smooth edges on leaves. These holes don't necessarily have to be at the edge of a leaf.
  • Evidence of silver slime trails
  • Damage on fruits and vegetables. For example, slugs feeding on strawberries and potatoes are relatively large, with circular holes leading into a similar width tunnel.
slug damage holes on leaves

Nemaslug®  2.0 is a natural biological slug killer for the control of slugs. It can be used to kill all types of slugs in your garden. It controls all of the most common species of small and medium-sized slugs which damage garden plants.   

nemaslug 2.0 packet

Nemaslug® 2.0 is produced in Littlehampton on the Sussex coast. The microscopic worms are reared in state-of-the-art technology borrowed from the brewing industry. The stainless steel fermenters are able to produce billions of beneficial nematodes. The nematodes are then packaged into small plastic trays and sent out with cardboard sleeves which include full details on how to use the product. The slug-killing nematodes are formulated in a water-dispersing powder. Because the nematodes are living, the plastic container should be kept in a fridge until use.

Nemaslug® 2.0 gives rapid effects on slugs. Once infected with the beneficial bacteria, slugs stop feeding, therefore no new feeding damage will occur on the plants. Slugs may take several weeks to die from nematode infection, but they won’t feed on plants during this time. As well as quick effects, applying Nemaslug® will also have a long-term effect on reducing the slug population within your garden.

Benefits of using Nemaslug® to control slugs in your garden:

  • Effective natural control of slugs
  • Fast activity. Slugs stop feeding soon after becoming infected with the beneficial nematodes, therefore no new plant damage occurs.
  • Even more effective during periods of damp wet weather, when slugs are more active.
  • Suitable for use in both early and late in the season as Nemaslug® is active at low temperatures.

How Nemaslug® works

Nemaslug® 2.0 contains a naturally-occurring beneficial nematode Phasmarhabditis californica. Found naturally in UK soils, the nematode is a natural predator of slugs. After application to the soil, Nemaslug® moves through the soil to hunt slugs. Once a slug is found, the Nemaslug® infects it through its breathing pore, and the slug becomes ill. Once infected and ill, the slug stops feeding and so no new damage will occur to the plants. The slug then burrows down into the soil to die.

slugs on lettuce

If the soil is kept damp, the beneficial nematodes in Nemaslug® will persist for 4-6 weeks, constantly hunting slugs to provide continued protection. If they do not find a slug to eat before running out of energy, the nematodes will then die.

Because Nemaslug® is a living predator, it requires certain environmental conditions to work. The soil temperature should be above 5°C and below 30°C. Most commonly the Nemaslug® is used between March and October. There should also be plenty of moisture in the soil, firstly to prevent the nematodes drying out and secondly to help the nematodes to move through the soil to locate a slug to infect.    

How to apply Nemaslug®

The aim of applying Nemaslug® is to place it into the soil in the intended area evenly. How this is achieved can vary depending on the area to be treated and equipment available.

Typically, a watering can fitted with a coarse (large-holed) rose or a hose-end sprayer are used.

It’s best to use all of the Nemaslug® pack contents in one go—it cannot do any harm to apply too much.

  • Mix the Nemaslug® gel powder into tap or rainwater in a bucket
  • Add some of the bucket contents into a watering can and then top up with more water
  • Spread over some of the area to be treated
  • Repeat the above two steps until all of the water in the bucket has been used

If you have dense plant foliage, applying extra water afterwards to help wash the nematodes down into the soil where the slugs live. If the soil to be treated has a lot of debris on it, such as leaf litter, remove this first so that it doesn’t create a barrier preventing the Nemaslug® from reaching the soil.

If the plants are protected by a frost fleece (such as BioFleece 30 or BioFleece 18) or an insect net (such as InsectoNet) this should be lifted off for the Nemaslug® application to help ensure good even coverage of Nemaslug® to the soil surface.   

insectonet biodegradable insect netting in garden

Peak egg-laying of slugs in gardens occurs first in early spring around March/April, and then a smaller second peak in early autumn September/October. However, when these peaks occur is highly dependent on the winter and summer weather conditions.

Because Nemaslug® is safe, there are no restrictions on eating fruit or vegetables from your garden which have been treated with Nemaslug®.

Best practice for using Nemaslug®:

  • Use immediately upon receipt – Fresh is best!
  • Aim to use against slugs when they are small.
  • Apply to soil temperatures 5 - 30°C
  • The best time of day to apply Nemaslug® is in the afternoon or early evening, out of direct sunlight and when it is cooler so the water which they are applied in is less likely to dry rapidly.
  • Apply in enough water to cover the soil area treated evenly. If Nemaslug® is applied to the plant foliage, apply extra water to help wash the nematodes off of the plants and into the soil.
  • After Nemaslug® application, water the area thoroughly to wash the nematodes down into the soil so that they are closer to the slugs they are trying to kill.
  • Keep the treated area moist for 4 weeks after the Nemaslug®


Best time of the year to use Nemaslug®

Nemaslug® 2.0 can be used year-round as long as the soil temperatures are above 5°C, so that it is warm enough for the nematodes to be active. The best time of year to apply Nemaslug® is when the slugs are small as they are more susceptible to nematode infection.

Outside in the garden the weather is typically warm enough to use Nemaslug® from March to October. Under protected conditions however such as a greenhouse of tunnel, it can be warm enough all year round. 

The most common times of the year to apply Nemaslug® are in spring and early autumn when peak slug egg-hatching occurs. If slug infestations are high in your garden, or in a “slug year”, applications can be made every 6 weeks from March to October.

Supporting natural predators control slugs in your garden

Hedgehogs, frogs and various birds as well-known as beneficials in the garden. They are natural heroes helping gardeners by eating slugs, hopefully before the slugs eat the plants. The beneficial nematode in Nemaslug® is part of this natural balance. It’s found naturally in the soil, just at low levels. Using Nemaslug® has no harmful impact on other natural slug predators which may be found in your garden.