Hans, how large a container do you have the Sulphur Queen growing in? I have 3 seedlings of Ismene in 2-gallon pots (ca 7 L.) and they are taking forever to grow.
Jim
Jim ,
it is not so big : 11 x 11 x 10 cm
I have repot this plant last winter
I grow also Ismene Festivalis in a bigger pot ...until no flowers
Same with Hymenocallis harrisiana ( same pot size )