After more than 35 years in exile, barberries have made a glorious return. They were banished in 1966 when some types were found to be hosts to Puccinia graminis, a fungus that infects cereal crops, such as wheat, barley and rye, with a devastating disease called black stem rust. Though some horticulturists believed that the Japanese barberry, Berberis thunbergii, was undeservedly targeted along with its more common and highly invasive European cousin, B. vulgaris, many barberries on public property were uprooted and carted away. On private property, however, mature specimens remained, taunting us with their beauty.
Since that time, American growers (the ban was not all-encompassing in the U.S.) have developed a number of rust-resistant cultivars of B. thunbergii. Last spring, after years of discussions between the Canadian Nursery Landscape Association and the Canadian Food Inspection Agency (CFIA), as well as Canadian cereal crop growers, 11 varieties became available in Canadian nurseries and garden centres, and more are expected to follow.
Shrubs with four-season interest
That's good news, because as well as being beautiful, barberries are easy to grow, make excellent landscape plants and offer four-season interest. They have small, yellow flowers in spring, vivid gold, chartreuse, orange or burgundy foliage in summer and fall, and on some cultivars, bright red berries that appear in October and persist into winter. Their dense habit and needle-like thorns make them first-rate barrier plants, and their ability to cope with pollutants makes them an excellent choice for urban gardens. One of the earliest plants to leaf out in spring (and the last to lose their leaves in fall), they'll grow in just about any well-drained soil and are relatively disease-free. They withstand pruning well and, when planted together, make handsome formal hedges.
Some cultivars grow well in light shade but all require full sun to show their best foliage colour. Apply an all-purpose fertilizer before new growth appears in early spring and water regularly the first year to establish a good root system. Most barberries are relatively slow growers and don't require much pruning; any pruning should be done right after flowering. Watch out for the thorns; they may contain a microscopic fungus, Sporothrix schenckii, which causes a skin infection called sporotrichosis. Although this generally clears up fairly quickly with medication, it can have much more serious effects for those with compromised immune systems. As a precaution, wear thick gardening gloves and long sleeves when dealing with barberries.
Photo: 'Monomb' Cherry Bomb