Berberis

Botanical/Latin
   Berberis

Pronunciation
   Ber-ber-is

Common Name
   Barberry

Hardiness zone range
   4-6

General Comments
Easy to grow, deciduous and evergreen shrubs with small yellow flowers carried on the undersides of branches in spring followed by small, conspicuous berries. Many selections have attractively colored foliage in shades of purple, burgundy, yellow and green all through the growing season, and then in autumn some even turn to glorious shades of red, orange, and gold. They have sharp thorns that to some gardeners can be a nuisance while to others it is a desirable asset by repelling intruders or directing pedestrians.

Light Preference
Full sun to partial shade, the forms with colored foliage tend to lose the intensity of color as the degree of light diminishes. For this reason, the purple foliaged ones are best grown in full sun.

Culture
They thrive best in well-drained soils that ideally are on the acidic side of neutral. They are not at all difficult to grow and usually perform well in most situations and soil types except wet, waterlogged conditions. They are free from any serious pests and diseases and require little maintenance, except perhaps a dressing of a well-balanced fertilizer in early spring before growth commences. They flower and subsequently fruit on shoots made the previous season, so with older plants it is worth considering doing some renewal pruning (taking out a proportion of the older wood) after they finish flowering. This helps to maintain shape and keeps them healthy and vigorous. Since the forms with colored leaves are grown for their foliage, clipping or pruning helps to encourage plenty of strong new bushy growth and, therefore, enhanced color. Regular trimming will not only maintain shape and form, but also add to the overall impact of the plants. This can be done at almost any time of year, but is probably best performed in late winter or early spring. On the other hand, this is not essential; if clipping or pruning these prickly shrubs is not your favorite activity, don't worry because good results are often achieved with the minimum of pruning or shearing.

Uses
They are wonderful accent plants, creating mounds of foliage color that really stand out in beds or borders. The smaller growing cultivars make good ground cover and can be used on sloping banks, in mixed plantings, or as low hedges. They have an advantage over several other hedging species in that they usually form a hedge quicker than most. The taller ones are widely used as hedging or screens, and in landscape settings they can be used as functional plants to direct and defend areas from pedestrians and pets. Once established, they are remarkably drought tolerant, so on large sites they are frequently placed in mass plantings.

Background
The name comes from an Arabic word, which apparently refers to the resemblance of the shiny leaves and fruit of some species to the inside of an oyster-shell. There are about 450 species distributed across South America, Africa, Asia, and a few in North America and Europe. In ancient times, the fruit and bark were harvested and used for medicinal remedies including the treatment of jaundice and typhus. A common characteristic of the barberries is that when the bark is peeled away they have yellow wood. In some European countries, the roots were boiled to extract a yellow dye that was used to color wool and leather. Another interesting characteristic is that the stamens (male parts) move inwards when the internal parts of the flower is touched, This natural adaptation helps to ensure cross fertilization, for when an insect moves inside the flower, the stamens close inwards and smear it with pollen before it moves to another flower. The cultivars we grow are derived from species that have oriental origins. The most commonly encountered ones are cultivars of Berberis thunbergii. The species name commemorates Carl Peter Thunberg (1743-1828). He was a Swedish botanist, a pupil of Linnaeus that was employed as a physician to the Dutch East India Company in Japan. He discovered this species in 1784, but it was not introduced to western gardens until around 1864. It proved to be hardy, easy to cultivate, and over the years numerous seedlings and variations have occurred especially in European gardens and nurseries. Berberis thunbergii 'Kobold' is a compact form growing into a 2-foot high mound (looks like a boxwood), with rich green leaves that turn red in autumn. It was introduced by Van Klavern nursery in Boskoop, Holland. Berberis thunbergii 'Aurea' has bright yellow leaves and makes a distinctive and eye catching accent plant. It grows to about 3-4 feet. A newer selection from France, Berberis thunbergii 'Golden Nugget' is smaller growing, holds its color better in late summer, and stands up better to hot sun. Berberis thunbergii 'Rose Glow' is a spectacular selection with purple leaves that are variegated with pink and white. It grows 4-5 high. It was raised around 1957 by the nursery firm of Spaargaren and sons, Boskoop, Holland and introduced to commerce around 1965. Berberis thunbergii 'Crimson Pygmy' This wonderful selection is also known as Berberis thumbergii 'Atropurpurea Nana'. It grows into a 2 foot high, rounded compact mound of striking, reddish-purple foliage. It was raised by Van Eyck, Boskoop Holland in 1942 and received an Award of Garden Merit from the Royal Horticultural Society in England in 1969. J.J. Gruellemans of Wayside Gardens, Ohio, marketed it in the USA under the name 'Crimson Pygmy'. These are all deciduous types (drop their leaves each Autumn). If you are looking for an evergreen, Berberis x gladwyensis 'William Penn' is one that performs exceptionally well for us. It develops into a 4-foot mound, with arching branches that are laden with conspicuous bright yellow flowers in spring. The dark green shiny leaves take on a bronze coloration as the temperatures drop in autumn and winter that adds to the overall appeal of this fine selection. The Henry Foundation for Botanical research, Gladwyne, PA, introduced it. (Mary Gibson Henry, a respected field botanist and plantswoman founded the Foundation in 1948. For more than 40 years, she traveled the North American continent selecting superior forms of known and unknown plants).

Splendor Suggestions
The dense, prickly framework of branches makes an ideal place for small birds to perch, shelter, and build nests, so consider placing some host plants near windows, patios, decks, or vantage points where birds can be watched (particularly in winter).

Companion Plants
The taller types can be used as accent plants with evergreen ground cover like Microbiota decussata (Russian Cypress), Juniperus 'Icee Blue' or Juniperus 'Blue Chip' or Euonymus fortunei 'Emerald Surprise' and 'Sunspot'. They could also be used as part of a shrub border, with Weigelas, Kolkwitzia (Beauty Bush), Lagerstroemias (Crape Myrtles) and the fluffy flowers of Tamarix. Evergreens like Ilex (hollies) and Buxus (boxwood) will carry the interest through the winter months while early flowering Forsythias, and other early flowering subjects like Helleborus orientalis (Hellebores), Doronicum magnificum (Leopard's bane) and drifts of bulbs like Muscari armenicum (Grape Hyacinths) will provide early season color. The dwarf forms look well with Callunas and Ericas, and in mixed borders they blend well with all sorts of perennials and grasses.