Oxalis flower open at night
Johannes Ulrich Urban (Sat, 15 Nov 2014 13:55:31 PST)

Dear All,

It is true that Oxalis flowers will only open in direct light, best is
direct sunshine of course.

But.... there is a trick to have open flowers any time of the day. Keep
the flowering plant very dark, like in a hermetically closed (to light)
box or a cupboard and then bring it into a well lit room at the time you
want open flowers. it may need some extra light to open the flowers
fully. This also works with other flowers that need direct light. The
effect will last for some hours. Commercial plant dealers do that at
plant sales.

greetings from dull November-weather in Germany, all flowers closed.....

Uli