Plants Used for Barriers

Aloe

• While aloe is often a useful plant to have around the home for medicinal reasons, it may also be used as an effective barrier plant. Aloe is a stemless succulent plant that grows low, and has prickly leaves with pointed tips. The plant also produces yellow flowers, which grow on stalks that may reach heights of 3 feet. Aloe does not tolerate frost, so it should only be grown outdoors in USDA Hardiness Zones 9 to 11. It grows best in partial shade, and has a high drought tolerance.

Crown of Thorns

• The crown of thorns shrub is an ideal barrier plant because it can grow as high as 5 feet high and as wide as 5 feet. It has also rows of spines along its stems, which makes it difficult to pass through. Crown of thorns, also known as Christ's thorn, grows best in full sun, and prefers a lighter-textured soil that drains well. It tolerates drought and wind well, so it ideal for warm, dry climates. Crown of thorn shrubs are often used in a low hedge or bank cover when used as a barrier plant.

Silver Thicket

• Silver thicket is ideal as a barrier plant because it features thick, sharp spines. It is a blue-green succulent that begins as a soft, green plant. Over the course of several months, it hardens and darkens to a blue-green color. The plant eventually develops into a tree, with a thick, gnarled wooden stem. It is topped by a balled-shaped cluster of spiked, blue leaves, which are effective in acting as barrier to keep out people and animals.

Barberry

• Barberry is a thorny shrub that serves as an effective barrier plant. There are several varieties of barberry, including Japanese barberry, wintergreen barberry and mentor barberry, and the shrubs range in height from 3 to 10 feet. Some varieties can also grow as wide as 10 feet, creating an ideal barrier for your property. Barberry shrubs are typically dense and have thorny branches. There are both evergreen and deciduous varieties, and their leaves may be various colors, including green, red, orange, purple and bronze. Barberry is a relatively low-maintenance plant, and is tolerant of poor soil and extreme weather conditions. The plant grows best in sun or partial shade, and requires fertilizer in the spring.