Barberry - Berberis sp.

General Information: The barberry is a thorny plant with yellow flowers. Some varieties are evergreen, some are deciduous. Native barberries are found on many continents, including both Americas, Europe and Asia. Barberry was once a popular hedge plant, but the tendency for some of its species, most notably B. vulgaris, to harbor fungus dangerous to corn and wheat crops has led to its virtual disuse. B. thunbergii and B. verruculosa are fairly disease-free and are making a comeback in popularity.

Lighting: Barberries need light for their leaves to turn their vivid colors. Evergreen species can be placed in semi-shade.

Temperature: Best grown in temperate zones. Deciduous barberries are hardy for colder zones than evergreens. All barberries have fine root structures which need a bit of frost protection if grown in shallow pots.

Watering: Moderate watering, although the barberry prefers it a bit on the dry side.

Feeding: Every two weeks throughout summer, using a very week liquid solution. Timed release fertilizer is a possibility, if it is not applied near the trunk. Barberries can be sensitive to salts, and the application of straight solid fertilizer can kill a tree. Barberries need little fertilizer, and plants in training pots or in the ground may need no fertilizer at all.

Pruning and wiring: The barberry flowers on one year old shoots coming off of two year old wood. Consequently, wait until after flowering to prune. Then pinch back new growth as it occurs. Barberries bud back readily. It is easier to shape the barberry through pruning than by wiring, as many species are stiff and have nasty thorns.

Wiring can be done throughout the year, but as the barberry grows quickly, check the wiring often. The major challenge with barberry is getting a thick trunk. Choose a nursery plant which is well-developed, and prune it back gradually, over the course of several years. If you desire a single trunked bonsai, watch carefully for the emergence of suckers from the roots, and remove them immediately before they sap trunk vigor.

Propagation: From seed, cuttings taken from softwood at the beginning of summer, or by air-layering. In addition, as the barberry suckers from the roots, it can be propigated by division.

Repotting: Every 1-2 years in early spring, before bud burst. Tolerates root pruning well, and up to half of the root mass can be removed. Evergreen species are slightly less tolerant; remove up to 1/3 of the root mass. Use basic bonsai soil.

Pests and diseases: Sawflies, aphids, powdery mildew, verticillium wilt, and rust have been reported, but the barberry tends to stay fairly pest-free.

Species useful for bonsai:

• Berberis atropurpureum
• Berberis aurea
• Berberis buxifolia - A semi-evergreen shrub, it gets its name from its leaves, which resemble box leaves. It has yellow flowers, and purple fruit in autumn.
• Berberis candidula: paleleaf barberry
• Berberis chenaultii: Chenault barberry
• Berberis darwinii - An evergreen species from South America. It flowers in spring with hanging blossoms of gloden yellow tinged with red, and has blue/purple fruit in autumn. It is not hardy in cold climates.
• Berberis haematocarpa: red barbery
• Berberis julianae: wintergreen barberry - Native to China, it is an evergreen species growing up to 8 feet tall. It has dark green 3 inch leaves which turn purplish-bronze in winter. It has yellow flowers and blue-black berries. Will grow in zones 6-8.
• Berberis koreana: Korean barberry - A deciduous shrub which will grow to 6 feet. It has yellow flowers, bright red fruit, and spectacular fall coloration. It flourishes in zones 3-7.
• Berberis x mentorensis: Mentor barberry - This semi-evergreen is a hybrid of B. darwinii and B. empetrifolia. It will grow to 7 feet, and has slender, arching branches and yellow flowers. It is happy in zones 5-8.
• Berberis stenophylla - an evergreen species. Has beautiful dark yellow, almost orange, flowers. However, forming a single trunk is reputedly difficult. It is best used with clump styles.
• Berberis thunbergii: barberry, Japanese barberry - A deciduous plant, with red or purple leaves and red winter fruit. It has yellow flowers tinged with red which turn orange in autumn. The leaves are small, up to 1 1/2 inches, making it a bonsai natural. It is found in zones 4-8.
• Berberis thunbergii 'Atropurpurea' - a very red cultivar.
• Berberis thunbergii 'Aurea'
• Berberis thunbergii 'Bagatelle': dwarf purple barberry - a dwarf form with foliage which turns dark red in summer.
• Berberis thunbergii 'Crimson Pygmy' - A cultivar with bronze-red leaves. Useful for bonsai because it does not sucker as readily as the species.
• Berberis thunbergii 'Kobold' - A green-leaved cv. which does not have problems with suckering from the roots.
• Berberis verruculosa: warty barberry - The branches of this shrub are covered with warts and thorns, and the autumn fruit is blue-black. It is an evergreen, with glossy green leaves. It grows only to 3 feet, and its leaves are under 1 inch long, making it choice for bonsai. It thrives in zones 5-8.
• Berberis vulgaris: European barberry

Bibliography:
Tomlinson's "Complete Book of Bonsai"
"The Creative Art of Bonsai," by the Samsons
Coats' "Garden Shrubs and Their Histories"
Owen's "Bonsai Identifier."
Florida Bonsai XI:1:7-9

Compiled by Sabrina Caine
Edited by Thomas L. Zane