Scientist on this summer's horror: What are the biggest mistakes we make when eradicating slugs?

Invasive slugs have become a significant challenge for gardeners in recent years, causing damage to plants and spreading across landscapes. Beyond private gardens, these pests can pose a threat to natural ecosystems. However, experts emphasize that the most effective approach to combating slugs begins not with the choice of product, but with understanding their presence and breeding habits.

While salt is a frequently recommended solution online, specialists note that it eliminates individual slugs but does not solve the underlying problem. "Salt destroys the actual slug, but salt itself is not good for the garden," explains an expert. "It gets into the soil, and one still has to chase after every slug." Whether slugs are eliminated with salt, vinegar, or mechanically, only a single individual is removed. The remaining population can continue to multiply if their breeding sites are not addressed.

“

Salt destroys the actual slug, but salt itself is not good for the garden. It gets into the soil, and one still has to chase after every slug.

Another common method, slug pellets, varies in effectiveness based on their composition and active ingredient concentration. "You need to know which granules to use, which ones have been tested," the expert advises. Laboratory tests have shown that granules containing around 1% iron phosphate often fail to kill slugs. These products may only slow their activity by disrupting their digestion, leading to reduced plant feeding. While this might appear to solve the problem for the gardener as plants are less damaged, the slug itself may not die and can continue to reproduce.

“

You need to know which granules to use, which ones have been tested.

Products with higher concentrations, such as those for professional use containing about 2.5% iron phosphate, can be more effective, especially against young slugs. However, the timing of application is crucial. Experts recommend using these treatments in spring, late autumn, or when young slugs hatch to significantly reduce population growth. Adult slugs may be less susceptible; in laboratory trials, some large slugs consumed granules but survived and even laid eggs, indicating they were not necessarily killed.

The most significant mistake gardeners make is eliminating visible slugs while leaving their breeding grounds intact. Experts stress that simply collecting or killing found slugs is insufficient. The priority should be removing places where slugs hide and reproduce, which are often found in compost piles, unmanaged plant waste, or damp areas.

“

If you give those granules to a large slug, it eats them and still laid eggs in our laboratory. This means it doesn't necessarily die.