Elizabeth Braimbridge of the Langley Boxwood Nursery, Rake, in Hampshire, explains that both the round-leaved box, B japonica, and the common box, B sempervirens, tend to bronze in winter, especially where exposed to bright, clear light and cold winds. This applies also to the dwarf form of box generally used for hedging. Mrs Braimbridge calls it 'protective colouring.'
Bad drainage can also cause discolouration of the leaves. Both box and yew are very fussy about having damp feet. The amount of rain we have had this winter has shown up problems that have, until now, been masked by more than usually dry weather.
Lack of nutrients causes a yellowish cast on the leaves, rather than a bronze one. It is a problem suffered more by box trees growing in pots than those in the open ground. And as Mr Hookings says he has dug in bonemeal and farmyard manure before planting, this is unlikely to be his problem. If he is lucky, he will see his box trees green up again next spring. If they do not, he will have to start mugging up on his drains.Reuse content