In a pot under glass they can leaf up prematurley and then get frosted off unless heat is given, too much however, and they will become drawn in the low light levels that are often present in the early months of the year. On the whole I prefer to keep the early growers under cool glass and the bulk of hardy species either bedded-out under cold glass or outside in raised beds under the shade of fruit trees. Here they benefit from the better drainage of a raised bed, and the shelter of the trees. A few, such as A.candidissimum , are grown in the open garden. In all cases they will benefit from deeper planting in colder areas.
Partial shade is very beneficial.
Soil or compost should be humus rich and moisture retentive whilst being well-drained. River sand and leafmould are essential soil conditioners. Some growers like to surround the tubers with sharp sand or Cornish grit. I do not practise this, as I feel that it all too often creats a sump around the tuber in just those conditions where the plant needs good drainage. I feed regularly.