Thank you so much for your comments re eremurus. I will split up what is in the pot and plant it in soil with good drainage. Another quesrion: I know that eremurus needs a dormant period. I kept it dormant last winter. It grew well with great strappy leaves this summers; but, didn’t bloom. Is it better to keep it dormant this winter? Should I divide it into a number of pots now, or in the spring? I have a bright greenhouse.
You have a challenging situation. Eremurus are really not suited to long term container growing, in part because of the fragility of their roots.
It is possible that your plants may not yet be mature enough to bloom. Mature (3-5 years old) garden-grown plants can be divided, if absolutely necessary, but again, very carefully.
Some valuable information about growing Eremurus, from the Royal Horticultural Society, can be found here.