Yams are another invasive edible here in Florida.
Common conditions here in Florida are:
Soil that is pure sand.
Intense
water in May/June/July.
Low amounts of sporadic water the rest of the year.
The ground never freezes.
It is happy growing in the shade here, but our light levels are substantially higher than those in more northern areas, more like full sun there.
Other useful information:
Yams are climbers. It is common to see
trees (in "waste" areas) that have been swamped by them.
The leaves are also edible -- although some people recommend cooking them first.
Perhaps some of this will be useful to you.