After harvesting our second lot of Maris Piper potatoes we discovered two or three small round holes on perhaps a third of the crop. These holes have typically been burrowed by wireworms.
Wireworms are the larvae of click beetles. Click beetles live in grassland so if you’ve had an overgrown plot or have created a garden veg plot where there used to be lawn you may be more susceptible to wireworm for the first few years of growing potatoes.
When harvesting the wireworm are usually long gone and the holes are small enough to cut out. Having these holes in your potatoes may affect the length of time they can be stored and may allow for further damage by other insects.
The following steps can be taken to alleviate wireworm:
- Dig over and cultivate the patch where you intend to grow your potatoes. Cultivating the soil will bring the wireworms and beetles to the surface where birds can get them. You may need to do this several times before planting to expose them as much as possible.
- Harvest and store potatoes as soon as they are ready to minimise the chance of being eaten.
- Create wireworm traps; take a potato, cut it in half and skewer some holes with a fork or small screwdriver. Place in the soil 5-10cm deep and leave for a couple of weeks. Hopefully these potatoes will attract the worms and be eaten instead of your main crop.
- Rotate where you grow your potatoes each year. After two or three years of cultivation and crop rotation the bugs will return to the grassland that they prefer and the problem on your plot should reduce.