Most of these species need well drained soil and moist conditions.
Mine are planted in equal part not too rich soil, and sand.
This works very well for me, but many growers only use potting
soil that is not to rich and drains well.
Alpines need a mixture of coursed sand, pebbles and potting soil,
or they can rot.

If you are planning to grow Oxalis Tuberosa, there are a few things you should have in mind.
Oxalis Tuberosa needs a longer growing season and are dependent
on day length, as they first form tubers  when the day length
shortens in autumn.
In areas with harsh winter climate, the cold can kill the plant before the tubers are completely formed.
Whereas in tropical areas, where day time is evenly longer, the Tuberosa can have difficulty setting a successful crop, because the days are not short enough.
But it is an oxalis worth growing, and it never hurts to try, does it?