The large brown slugs are regular Spanish slugs, the light-brown ones are Arion slugs, the beige one in the middle is a Grey garden slug and then we have regular snails in the top of the picture. Keep reading if you want to know how to get rid of slugs in the garden!

It's been a bit rainy and damp lately, and you know what that means... Slugs! We were just hit by a massive invasion of slugs in the garden. In a way, I feel glad that I haven't been able to transplant that many seedlings outside yet. It's just been too cold so far, which of course means that the slugs didn't get very much to eat. I did however notice that they ruined the carrots in my 20 ft (6 meter) long bed. That just broke my heart! I'm sowing new carrots now though. And I'm going to get rid of slugs in the garden with the help of nematodes too.

I have plenty of different slugs and snails in my garden. The Spanish slug, Orange-banded Arion, Grey garden slug, Leopard slug and many more. Thankfully, no Burgundy snail though!

There are plenty of ways to get rid of slugs in the garden. I use what I believe to be the most practical methods. First, I pick slugs (with the help of my kids.) Then, I scatter ferramol in the spots I know they often pass by. Finally, I keep a batch of sourdough in my polytunnel as a trap for the slugs, and I also water my plants with nematodes.

Read more: Maria's sourdough slug-repellent

This is what the nematode batch looks like, the white powder in the bottom of the picture.

Get rid of slugs with nematodes

So, what are nematodes? Well, they are shortly put tiny little parasitic worms. You put them in the watering can and use the nematode-filled water in your garden. When the nematodes reach the soil, they find any slugs nearby and find their way into their bodies. The slugs will stop eating and slowly die off. The nematodes reproduce in the slugs and then you have even more nematodes to kill off slugs in the garden.

Spanish slugs often eat other slugs and snails, and that's how the nematodes spread to a large number of slugs in the garden. But there are a few things you can do to speed this process up. I use what I call the Norwegian method. This is all about collecting slugs and snails and then letting them soak in a little cocktail of nematodes. The snails affected by nematodes are then placed in the garden as bait for other slugs. This has actually been working really well a number of times. The last two summers have been very dry and we didn't have that many slugs around, so I only watered my beds with the nematodes. I plan on collecting and preparing new slugs in this way again if we get a little more rain in the future.

More about spring gardens: Ninnie's Swedish Cottage Garden

Nematodes kill slugs, but they actually don't affect any other animals. You can use them in your garden even if you have pets around. You don't have to worry about livestock either.

I'm using the Norwegian method to get rid of slugs.

What I do

The size of your garden will determine how many nematodes you need. I order mine online as a subscription, for 100 square meters. They say that nematodes will last around 6 weeks, and then you need to go through the process again. Since I have two gardens now, I order 2 x 100 square meters. There are plenty of companies online that sell nematodes to get rid of slugs, all around the world.

You can use the nematodes early in the season too, as long as the temperature is above 5 degrees Celsius (41 degrees Fahrenheit.) Try to water with nematodes when it's cloudy or even raining outside. The nematodes might not make it in strong sunlight or excessive heat. I often try to do it at night in the summer, because it's a little cooler then.

I split every batch of nematodes into eight separate batches and then I use one batch per every 10 liters (2.6 gallons.) You just add the nematodes to the water and stir, and then you use it to water your beds. I try to prioritize the areas where I know they often go, like underneath the currant bushes, around my polytunnels, next to the pasture by my kitchen garden and some of the more overgrown parts of my garden.

More about protecting your plants: How to use row cover in your garden

I'm preparing four watering cans at once with nematodes.

I make eight little portions from every batch.

You can just use a regular spoon to scoop up the nematodes and put them in the watering can.

Slugs and mulching

I'm a big fan of mulching, which might come as a surprise to some strong-minded slug-haters. I have to say that the slugs don't actually put me off mulching at all. In my mind, the slugs will be there no matter if I mulch or not. But if I don't, I miss out on the boost that both vegetables and flowers really need. I would of course lose plants to the slugs no matter what I do, so I just prefer growing them in a way that I know works. With mulch.

It's actually not harder to get rid of slugs in mulch either, the nematodes do the trick here too.

Read more about mulch: How much mulch do I need?

It's summer 2019 and I'm using nematodes for my cabbage patch. I decided to mulch my bed with wool.

I hope you try using nematodes to get rid of slugs in your garden this summer!
/Sara Bäckmo