Pampas Grass (Miscanthus species)
Description: Pampas grass is a popular horticultural bunch grass used in landscaping and gardens. There are many different varieties, with a host of common names such as: susuki, fairy grass, chinese sedge, japanese silver grass, and maiden grass. Pampas grass has a branched, subterranean rhizome system. It spreads by wind blown seeds and by rhizomes. Pampas grass can grow from 3-7 feet tall. The attractive fall color of the stems and seed head can at first glance be mistaken for Indian Grass- a native prairie species- but that is where the similarity ends. Pampas grass has escaped from gardens and yards and has readily colonized waterways, pastures, roadsides, etc.
Distribution: Pampas grass grows quickly and aggressively in roadsides, pastures, waterways, waste areas, fencerows, old homesites, etc.
What’s The Problem?: Pampas grass produces an extremely thick grass stand which excludes other native vegetation, and provides little in the way of wildlife food. It also spreads aggressively and colonizes uninfested areas quickly. Pampas grass is difficult to control if it gets established.
Management Methods: Once well established, pampas grass is particularly difficult to eliminate. Pieces of rhizome as small as ½ inch can reproduce and send up new shoots. The whole underground rhizome must be killed to prevent regrowth the next year. Hand digging may only encourage resprouts to grow. Disking and cultivation may only spread pieces of rhizome into uninfested areas. Some success has been demonstrated using intense, close grazing with farm animals. Pampas grass also tolerates repeated close mowing, so mowing is not a preferred management method. Use of prescribed burning to remove dead or dormant stalks, followed by application of a burndown herbicide after regrowth has been shown to improve control. Be certain to correctly identify plants and use the proper chemicals at labeled rates. Be sure to read and fully understand chemical labels before usage. Populations must be monitored to prevent resprouting or spread into new areas. Competitive seedings can also be used in conjunction with other control methods. One of the most important things which can be done to prevent the spread of pampas grass is to discontinue its use in plantings and garden. It’s color and ease of growth has persuaded many citizens to use this extremely invasive plant that is spreading into unintended areas. Pampas grass can drastically reduce diversity of native plants, such as prairie grasses and wildflowers. Many of the cultivars of Miscanthus have not been studied to determine if they pose an invasive threat. Until these varieties have been tested, caution should be used in planting them. There are many suitable native and non native grass species which are both colorful, relatively easy to grow, and do not pose an invasive threat.
Photos courtesy of Corp of Engineers