All your Slug Nematode Questions and Answers

Using nematodes to controls slugs is easy, effecting and safe.  Here are some of the most asked questions about this biological control and their answers.

When should you use nematodes for slugs?

Nematodes for slugs and vine weevil can be used when the soil temperature reaches 5°C and should be used every 6 weeks until the temperatiure drops below 5°C late autumn.

Are nematodes safe for pets/kids?

Yes, you can allow dogs, other pets, children to play on treated areas immediately as our nematodes are 100% biological and safe.  Read more about dogs and slugs here...

Are nematodes ok to use on edible crops and in organic gardening?

Yes, nematodes are 100% biological and there both safe for edibles and endorsed for use in organic gardening by The Soil Association.


Can I use different types of nematodes at the same time (i.e. vine weevil and slug)?

Yes, you should apply the separately but they can be used on the same area at the same time.

What are nematodes and where do they come from?

Nematodes are microscopic eelworms and they are naturally occuring in the soil.  They are target specific, meaning that each species only has one pray.  The ones we sell are mass produced on artificial diets.  They are produced in the UK, on the south coast.

Don't nematodes affect plants and humans?

Lots of people ask why the nematodes we sell are not harmful to plants, humans or wildlife.  There are many many species of nematode in the natural world but they are all target specific.  We sell nematodes for specific garden pests and they do not affect anything else.  By applying nematodes to you are garden you are boosting a population that is already there without upsetting the delicate ecosystem.



Can you see nematodes?

Nematodes are tiny, microscopic colourless worms so they can't be seen with the naked eye.

How do nematodes work?

Nematodes work by infecting the host with a lethal bacteria.  They enter via the digestive or respiratory system of the pest and stop that from working.  This stops the pest from feeding within 48 hours and eventually kills the pest within a few days.  They reproduce inside the pest and release further generations into the soil.  You can find out more about how they work here...

Do nematodes kill snails?

The species of nematode that kills slugs works on the slugs underground so does not have the ability to kill snails.  Slugs and snails are seen to avoid areas treated with Nemaslug nematodes so they can be used as a natural deterrent to keep snails numbers down in your garden.

Why are nematodes more effective against slugs than pellets, traps or barriers?

There are up to 95% more slugs in your garden then you ever see as the vast majority live underground.  Only nematodes will reach this part of the population and stop then decimating the roots of your plants or making their way to the surface to do that damage above ground.


What time should I apply nematodes?

As it's important that the soil, or plant if using as a foliar spray, must not dry out after nematodes application it's often best to apply late in the day and out of direct sunlight.  Once you have opened the package and mixed up the solution you only have a few hours to carry out the application.  The nematodes will drown if left too long.

You also don't want to apply nematodes then go away for a few days as you will need to make sure to keep the area damp.  To save you some time, and water, it's a good idea to look at the weather forecast and plan to do your application when rain is due.

 How to apply nematodes (soil drench)

All our nematodes come with detailed instructions that should be followed to the letter so we will not go into specifics here but in preparation for receiving nematodes here's a few things you should do/make sure you have;

  • Ensure the soil or compost is well irrigated and not compacted
  • Ensure the soil is above the minimum required temperature
  • Clean the equipment you are going to use to apply the nematodes
  • Have available a watering can with a course rose or a hose end feeder for large area applications

 What happens to nematodes after they have killed the pest?

Nematodes reproduce inside the pest and release further generations into the soil.  If there's not more of their prey around then they will die back to their natural levels.


If you have any other questions about nematodes and their application please get in touch via