Hi Reneross and welcome to GoY. Your soil looks a little dry to me but that is just looking at the photos. Are they getting baked perhaps by the sun? Alternatively they may need thinning out again :)

my first thought was too much heat from the wall behind them. Perhaps into a shadier spot?

About where in South Africa are you, Reneross? We don't need the details, but if your night temperatures are exceeding 27º C, they may be going dormant for the summer, like ours do, here in southern Arizona.

Hi friends, thanks for all the replies and comment. Sorry for the delay in replying - i have been travelling.

I live in Pretoria, SA. This is just the begining of our summer and our temp. ranges from 11*C at night to about 29/32*C at max. This lily patch is quite old but it is the first time we have seen this curling of leaves. Could it be a sign of rootrot? The stems and flowers don't appear wilted however. I did inspect the roots for bugs but could not find anything unusual. I dont know what rootrot looks like.

The wall is orientated in such a way that it only gets late afternoon sun. The plants get full sun from 14h in the afternoon.

Thank you so much for trying to solve my puzzle.

Kind regards
Rene

Well, from the looks of them, I would suspect either sodium buildup, or magnesium deficiency. They are also probably overdue for division, but I am uncertain when that should be done in your area--usually at the end of their normal dormant period. Good luck! :)

Thank you so much ! I will certainly try nutrients. Bless you!