Berberis

                                           by Barbara Kirbach, Sonoma County Master Gardener

Berberis (Barberry) is a genus of ornamental, evergreen or deciduous shrubs that is said to include some 400 species, the majority of which come from the temperate zones of East Asia, the remaining from North and South America.  Some botanists maintain that the North American species and in particular, the California species, should be classified as either a distinct genus or as Mahonias. This is due to the fact that their pinnate leaves and spineless branches differ markedly from true barberries. However, other leading botanists have recently ruled that the California species should remain in the genus Barberis.  We’ll leave the California species for later in the year, and focus on the others here. 

No matter how they are classified, Barberries’ pale yellow to orange flowers, waxy red to purple berries and dazzling foliage covering the full spectrum of autumn colors and spring greens, make them one of our most beautiful shrubs.  Ranging in size from compact to tall, the shrubs can serve as a low ground cover, an attractive medium-sized hedge or a tall, sturdy screen. The wicked spines along the stems are a constant deterrent to deer, cattle and other trespassers. Graham Stuart Thomas once commented that the incredible beauty of barberry foliage must be the reason why gardeners are willing to overlook their thorns, and that they are also valuable in combating hooliganism.

Barberries are easily cultivated.  They thrive in sun or shade, but their beautiful fall colors and berries are more advantageous with full sun. Many species can endure extremes in temperature and can grow in almost any soil, so long as it is not water- logged.   All are durable, disease resistant plants, sustaining only an occasional attack by cabbage looper caterpillars, which can be picked or hosed off or given an application of BT (Bacillus thuringiensis). The shrubs are generally drought tolerant, needing only a minimum of water during a hot, dry summer.  They require little maintenance, save for a light pruning to remove unshapely canes in the early summer after blooming.  In especially poor soils, the plants may appreciate a light feeding of a balanced fertilizer and in alkaline or saline soil, a dose of iron sulfate. The shrubs may be propagated from seeds, new shoots from rhizomes or from stem cuttings. My B. Thunbergii has produced several multi-branched offspring to share with my Sonoma neighbors.

Berberis thunbergii
Japanese Barberry (Deciduous) This species and its cultivars are the most commonly planted of the genus. This small to medium-sized shrub has densely massed branches covered with small, oval and some variegated leaves that progress from green to yellow, orange, red or purple before they fall to the ground. Tiny clusters of bell-shaped, yellow-green flowers appear along the stems in mid-spring followed by small red berries that punctuate the slender, arching, spine-covered branches in the fall and winter. 

     B. Thunbergii ‘Atropurpea’, Red-leaf Japanese barberry. Foliage changes from a   purplish brown to a  bronze red in the fall. If given full sun, its intense red color will prevail all summer.

    B. Thunbergii ‘Atropurpea Nana’, Crimson pygmy. This is the runt of the genus as it grows only 1 to 1 ½ -feet high and 3-feet wide. Leaves begin as a clear red and mature to a blood red. Also needs full sun to develop color.

 
    B. Thunbergii ‘Golden Ring’ is named for a golden edge that rings its dark reddish- purple leaves in the spring.  This compact 3-feet by 3-feet species bears the familiar bell-shaped, yellow flowers, which are followed red berries. 

    B. Thunbergii ‘Helmond Pillar’.  A row of these pillars, which grow upright to 4 to 5-feet tall and just 2-feet wide, provides an excellent backdrop to a perennial border or a screen for an unsightly view. Lovely bright red leaves.

    B. Thunbergii ‘Rose Glow’ grows 4 to 6-feet tall. New foliage is bronze red to light pink, changing to purple and bronze as it ages. Plant in full or lightly filtered sun for best color.

Berberis wilsoniae
Named after the wife of English plantsman E H Wilson, Wilson's Barberry is an evergreen shrub (some occasionally deciduous) which grows from 3 to 6-feet tall and wide. Webmaster Steven Hightower describes his plants as having “fountaining, arching branches with beautiful tiny, pale flowers in spring followed by berries that appear almost translucent, then slowly turn red.”

There are a number of other species that are equally attractive and useful in the garden, but not as commonly planted.  B. darwinii is a large evergreen shrub, with golden, almost orange flowers.  B. caliantha is also evergreen, but quite petite.  B. x stenophylla ‘Corallina Compacta’ is, as its name suggests, a low-growing, compact plant with coral berries.  Once you investigate barberries, you’ll want to know them all!

Many of the Berberis shrubs described above may be found locally at California Flora Nursery, Digging Dog Nursery, Emerisa Gardens, Sonoma Mission Gardens and Wedekind’s Garden Center.