Slug Damage to Potato Crops

Spuds are a hard crop to grow. They take up a lot of space in the garden and require a lot of ground preparation and care to ensure a healthy harvest. So it can be very disheartening when, after a summer of tendering your crops you find that your harvest of potatoes has been attacked by slugs!


The first slight can be a bit revolting as we go through the emotions of anger, sorrow and guilt of a crop lost to slugs. It’s certainly not a happy time in the garden! Those miserable slugs sitting inside potatoes rotting them from the inside out!

So how can we combat this pest you ask? Slugs are truly the worst offending pest of them all and because of that there are many control options. But the slugs that attack potatoes are a little bit different – These slugs live predominantly under the ground and so; above ground pest killers and barriers are not effective at controlling them. That said – all slugs can burrow and exist under the ground and this is the main reason why all slug defence barriers such as wool, pellets, grit, copper, egg shells and ashes are not 100% effective

So, how can we control a slug that burrow and lives in the soil? The best option is to use the biological control nematode. This is a parasitic worm that is very tiny and lives in soils. It can be bought from horticulture suppliers & garden centres and is applied to the soil in spring. The nematodes work their way into the soil and colonise the soil eating their way through slugs in the process. The result is a more balanced soil ecosystem where small number of slugs and nematodes live together.

Slug damage to potato starts in August and can get progressively worse as the season wears on. To prevent and reduce damage to your crops you should harvest your potatoes early if damage is noticed. Regular harvest and inspections should be carried out throughout the month of august

Slug damage to potatoes is similar to wireworm damage. To spot the difference see the image slideshow above. You will notice that wireworms leave smaller tunnel like holes in potatoes, while slug eat larger crevasses

Another way to prevent slug damage to seed potatoes is to choose slug resistant varieties such as:

  •  Arran Pilot
  • Desiree
  • Sarpo Mira
  • Lady Rosetta
  • Golden Wonder
  • Romano
  • Pentland
  • Charlotte
  • Kestrel
  • Estima
  • Growing early potatoes is also a good way to prevent slug damage as these are harvested before the august onslaught

If your soil is prone to heavy infestations then some seed potatoe varieties to avoid include

  • Maris Piper
  • Roosters
  • Records

Soils more prone to slugs include wet and heavy soils as these are ideal for slugs. Also soils close to thick cover such as long grass or old, fallen leaves have higher slug populations as this provides a good habitat for slug to overwinter.

When crops have been attacked the potato are not suitable for storage as damaged areas rot quickly therefore potatoes need to be eaten soon after harvest