Ribbon grass, Phalaris arundinacea, is a deciduous ornamental grass, meaning that the plant sheds green foliage during the winter before producing new foliage in the spring. Ribbon grass is a rapidly spreading grass that produces dense, carpet-like coverage. On average, this species reaches heights of around 3 feet (90 cm).
This grass is tolerant of a wide range of conditions, including both hot and cold climates with low to high humidity, as well as a substantial range of pH, from 6.1 to 7.8. Ribbon grass continues to thrive in nutrient-poor soils but will not tolerate long periods of waterlogging. The resilient nature of this species means it is often used as extensive ground cover in nutrient-poor areas. The dense masses of roots and dense, carpet-like foliage also mean the plants are commonly used in areas at risk of erosion. Although ribbon grass is tolerant of a wide range of conditions, optimal growing conditions include partial shade and free-draining soil; if grown in full sun, the plants are often slightly less dense and can develop a straggly appearance.
The way ribbon grass continuously spreads means it is considered an invasive species in many countries and areas where it has been introduced. It forms dense carpets as it spreads, limiting light, space and nutrients for other species. It can pose a serious threat to the survival of some native species in localized areas.
Ribbon grass is a rhizomic plant, meaning that it spreads using underground rhizomes. Rhizomes are tough, underground trailers that travel away from the main plant, sending up new shoots above ground level; those shoots then form new plants as the rhizome continues to travel outward. The new plants form their own root systems, independent of the parent plant, and eventually form their own rhizomes. The process forms dense mats of roots, ensuring the survival of the ribbon grass to the exclusion of most other plants.
Ribbon grass is native to Europe and North America but has been naturalized throughout most of the world. To contain ribbon grass and minimize the risk of the plant spreading out of control, ribbon grass can be grown in containers to create a striking ornamental display. Standard ribbon grass has green leaves with white stripes, but there are several other cultivars for those wanting a bit of variety; picta is similar in color to standard ribbon grass but has more white on its leaves and is less invasive.