Hello , can t see your pic but yes it is good to divied Agapantus at this time of the year or Oct Nov ....I do this every 4 years and put high potash..hope this help

when I split mine I use a bread knife as it cuts really well.
I do mine about now when I do split them.

I split mine last autumn, and all the plants are doing well. They’re in pots and I’ve kept them in the potting shed through the winter.

Thank you all. I’m still undecided whether to split now or in the autumn though I’m leaning towards autumn as, by then, it will be three or four years since they were last done.

Thanks again.