Plant Taxonomy of Japanese Barberry:
Plant taxonomy classifies Japanese barberry as Berberis thunbergii. Cultivars include 'Crimson Pygmy' and 'Aurea.' Another well-known species is the common barberry or "European" barberry (Berberis vulgaris).
Plant Type for Japanese Barberry:
Japanese barberry is a broadleaf, deciduous flowering shrub.
Japanese barberry shrubs often reach a height of 6 feet at maturity, with a similar spread.
The bush bears green leaves, yellow flowers that bloom in spring, sharp thorns, and red, oblong berries that persist well into the cold-weather months for winter interest.
Both Japanese barberry and common barberry are invasive plants. This article is offered for research purposes; its publication in no way represents an endorsement of the planting of Japanese barberry. For more on the invasive aspect of the bush, see "Invasive Plant" below.
Planting Zones for Barberry Shrubs:
Indigenous to Eurasia, Japanese barberry shrubs can be grown in zones 4-8.
Sun and Soil Requirements:
Other than requiring a well-drained soil, these shrubs tolerate a wide variety of growing conditions. This tolerance helps account for the shrubs':
Specifically, they tolerate pollution, shade and drought.
Traditionally, these shrubs were used in hedges; with their sharp thorns, a row of such plants would, indeed, serve as a "living fence." The bushes are also effective for erosion control. One of the most deer resistant plants known, they are especially popular in neighborhoods overrun by deer.
Origin of the Name, "Barberry":
"Barberry" and its genus name, Berberis derive from the Arabic name for the fruit, barbaris. Both the plants themselves and the berries they produce can be referred to as "barberries."
As mentioned above, 'Crimson Pygmy' and 'Aurea' are two Japanese barberry cultivars. 'Crimson Pygmy', true to its name on both counts, bears reddish purple foliage and stays short (at most half the height of the species plant, and usually less). 'Aurea' is also something of a dwarf (3'-4'); its foliage starts out a vibrant yellow.
But as already stated, Berberis thunbergii is an invasive shrub in North America, where the bush has naturalized in some areas. And apparently, growing these cultivars instead of the species plant does not obviate the problem. According to Boston.com, Jonathan Lehrer, at an invasive plants conference, "presented a study that found Japanese barberry cultivars such as the popular Crimson Pygmy can...produce seedlings that revert to the more invasive green form."
In the future, you may be able to buy a Japanese barberry shrub that is not invasive. Lehrer is one of the researchers who has been trying to develop a sterile version of Japanese barberry. Stay tuned. I'm in no hurry, myself, as I'm not a big fan of prickly plants. Landscaping with barbed wire is not my idea of fun.