Holed potatoes is either keeled slugs which live in the soil and are very hard to get rid of. Dig over the soil and expose it to the birds and keep raking it over to bring up more of them for the predatores, encourage ground beetles as they eat slugs. Or wireworm, again hard to control but treatment as above. Club root lives in the soil for a very long time and feeds on ANY member of the Cruciferae family, like Wallflowers or Wild Mustard or Charlock so it is hard to eradicate. It does not thrive in limey soil so liming does help a little. One way to give your plants a better chance is to grow them in limed compost in pots and plant out the whole root ball, the fungus does not move that quickly into the new soil so the plant has time to grow strongly. Cannot help with flatworms though, except to lend you a large heavy boot. Eric
