Plant · P-420

Hardy Orange

Citrus trifoliata

Hardy Orange is by far the most cold-hardy member of the citrus group, shedding its leaves in winter as part of what buys it that extra hardiness, and it doubles as the standard rootstock used to add cold resistance to tenderer citrus grafted onto it. Its 1 in thorns on green, striped twigs make an excellent impenetrable hedge, and the bitter, acrid fruit still yields juice rich in vitamin C for marmalade once stored a couple of weeks. It self-sows freely by animal-dispersed seed and can colonise woodland, forest edges, fence rows and urban green space if left unchecked - useful vigour where a thorny stock-proof hedge is the goal, less so where it isn't, so pick the fruit before seed drops and mow or graze the margin to catch seedlings small.