You can read more regarding growing South African oxalis on
It is very informative, helpful and easy to follow.
A few years back I lost many oxalis due to two factors;
they were watered during the day and the heather went out during the night when temperatures dropped way under freezing point.
Everything was brick frozen when I returned home the following afternoon.
This regardless many bulbous South African oxalis seems to be hardier than expected. As long as the bulbs are not allowed to freeze up completely for to long, some species can recover.
According to The South African Weather Service, temperatures in this region are
from 26 to -2 C.
This seems a large difference to achieve in an heated environment. Here the oxalis are grown in temperatures between 10 to 1 C, which seems to be the coolest they can take.
I´m trying to gather information on oxalis hardiness.
If you have some experiences you would like to share with
us please ad them here
The following words are meant to give a little insight on these fascinating and at times challenging species.
Most winter growing oxalis grow naturally in South Africa, but are also found in the Mediterranean and parts of South America.
In their natural habitat summers are too hot for them to thrive, therefore they grow and bloom from autumn to early summer, during the rainy and cooler winter months.
That time of year is from around late July to May in the northern hemisphere.
South African winter conditions can be difficult to obtain in some parts of the northern hemisphere as it can be to cold.
Moreover oxalis also need much sunlight for the flowers to open, something that is not always possible here (Denmark), were the winter has mostly grey days
Therefor a solution could be to grow them in a cold frame, a heated greenhouse or in a tool shed with lots of light.
Planting oxalis Bulbs
I have lost too many oxalis bulbs by planting them in rich heavy potting soil, or trying to grow them indoors at the window shelf. They simply just rot or etiolate. That is why I really would`t recommend you invest in these bulbs, if you are not able to give them good growing conditions.
Many of the South African oxalis were in limbo until Bill, my fellow oxalis enthusiast and friend, gave me his excellent method of growing them.
It was in the middle of winter, and the ingredients were impossible to find.
Solution; I bought coarse sand and pebbles used for aquariums and moler clay used for cat litter, optional, and it works wonderfully.
Reasontly I have discovered that regular welldrained potting soild or light potting soild used for seedlings, works well for some of these species as well.
Temperatures are in Celcius