Hi Organicbynature, Welcome to the Gardeners Forum.
Starfish wrote:
Reason mainly is that my soil is plagued by eel worms or somesuch.
While waiting for organicby nature's reply,
You can try companion planting with French Marigold [Tagetes patula]. The marigold roots secrete chemical that kills/reduces eelworms population. Since you are planting
potatoes in tubs, just make sure there drainage holes at the bottom of the tubs. If possible, use fast draining acidic soil with a pH range of 4.8 to 5.4.