Hybrid Citrus 'Benton' (Poncirus trifoliata x Citrus sinensis)

Woodlanders has long championed hardy citrus, the trifoliate hybrids that push oranges and their kin well beyond the usual citrus belt, and 'Benton' is one of the toughest of the group. The plant is a citrange, a deliberate cross between the sweet orange, Citrus sinensis, and the hardy trifoliate orange, Poncirus trifoliata, that legendary deciduous, thorny survivor of cold-country citrus breeding. The name citrange simply fuses citrus and orange, and the hybrids inherit the trifoliate orange's remarkable cold tolerance.

'Benton' originated in Australia and carries the citrange's practical reputation: cold hardy, dense, thorny, clothed mostly in trifoliate leaves, and grown as much for use as for looks. Like most citranges, the fruit is not much for fresh eating, tart and seedy, though the juice, diluted and sweetened, makes a refreshing orangeade. Growers value the plant chiefly as understock, the rootstock onto which more tender citrus is grafted, and 'Benton' has the added quirk of sometimes producing curious fingered fruits.

In spring the shrub opens fragrant white flowers, often brushed with purple on the outer petals, the unmistakable perfume of citrus in a plant that can take real frost. That bloom gives way to rounded, orange-like fruit that ripens more cold-tolerant than any true orange thanks to the trifoliate parentage. Unlike a tropical citrus, 'Benton' is only semi-evergreen: in the Deep South the shrub holds much of the foliage through winter, while colder gardens see the leaves thin or drop before spring pushes them back.

For the garden, 'Benton' works as a hardy, ornamental novelty and a formidable barrier. The dense, thorny frame makes an effective informal hedge or security planting, and the fragrant spring flowers, trifoliate leaves, and odd winter fruit give the plant year-round interest in full sun. Site the shrub in well-drained soil where the spines will not surprise a passerby, and enjoy the rare pleasure of citrus fragrance in a climate too cold for oranges.

Photo credit: UC Riverside, Givaudan Citrus Variety Collection.