I grow Kniphofia sarmentosa in a container. In my area it is a late winter bloomer. So far it has been coming back nicely every year. To be honest I have not amended the soil yet. It goes to sleep here during summer, and just comes back when the cool temps of Fall returns. When I planted this, I made my media very well draining, using succulent mix adding pumice and some compost. Winter is our rainy season, and it seems to thrive in that cool winter rain and then followed by good dry out time.
I tried two other Kniphofias - Kniphofia caulescens and Kniphofia hirsuta 'Fire Dance', both blooms in mid to late Spring. But both did not stand our summer heat or maybe I have underwatered them too much so they just did not make it anymore. Too bad, I really like the compact growth of Kniphofia hirsuta 'Fire Dance'
It was good I tried them, taught me that our excessive duration of dry heat here is too much for some plants to handle, even in shade.
