Q What groundcover will give winter interest under a hedge in sun?
AJAMES SAYS Winter interest groundcover for a sunny spot can be a bit of a conundrum. However, I think the light shade cast by your hibiscus hedge can open up your choices a bit. I would go for a carpet of beautiful ivy-leaved cyclamen (C. hederifolium), which have exotically patterned leaves and a delicate sprinkling of pink flowers in late autumn and early winter.
I see you’re in the mild climate of London, so you could combine the cyclamen with a soft mossy swathe of mind-your-own-business (Soleirolia soleirolii). Unlike the cyclamen, this is evergreen so will suppress weeds all year round. These two will make good bedfellows beneath your hedge.