This excellent evergreen agapanthus stands beautifully upright on sturdy stems.  The flower heads are around 4”/ 10cm.  Because it is an evergreen, it starts to open with us around the end of July, early August and then continues with its display through the month.

We used to cover it every winter, but did not during 2019/20, which was, admittedly, mild and it was fine.  I think it is extended periods of frost that cause damage, not short dips.