Pampas Grass vs. Fountain Grass

Appearance

• Both of fountain grass and pampas grass grow in clumps with narrow green leaves, topped off by feathery plumes extending above the tufted plant base. The most notable difference between the two plants is size. Clumps of fountain grass are 1 to 3 feet tall and wide while pampas grass is significantly larger, growing up to 10 feet tall and 6 feet across. The lightly colored plumes serve as the focal point for both plants. The color of the flower plumes, which bloom from July through late autumn, varies depending on the specific cultivar, and range from pink to purplish for fountain grass and silvery white to pink for pampas grass. As the plants go to seed in autumn, the plumes turn light tan in color and then shed.

Growth and Propagation

• As perennials, fountain grass and pampas grass plants survive from year to year within their respective U.S. Department of Agriculture plant hardiness zones: 5 through 9 for fountain grass and 7b through 10 for pampas grass. They are both warm season grasses so are most vigorous and attractive from spring through fall, though they do not go dormant and may have flowers throughout the year in warmer areas. Fountain and pampas grasses both self-propagate through seeding, but commercially available pampas grass is typically propagated by dividing existing plants. That’s because the plumes of female pampas grass plants are much showier than their male counterparts and the only way to ensure you will have a new female plant is to divide an existing female clump.

Care

• Once established, fountain grass and pampas grass are the epitome of low-maintenance gardening. Planted in well-drained, fertile soil that gets plenty of sun, both of these plants will thrive with minimal watering and little else. Of the two, fountain grass is the more forgiving, as it can tolerate more shade as well as moister soil. When planting, keep the ultimate size of the plants in mind and do not crowd them. Overzealous gardeners often find themselves having to pull out some plants after a year or two to make room for maturing plants. Even though they are low-maintenance, these plants do even better with a little regular maintenance. Periodic light pruning to remove yellow or brown leaves is helpful for both types of grasses. Pampas grass can also benefit from severe pruning every two years or so to remove old foliage and make way for new growth. Since both fountain grass and pampas grass can spread quickly through self-seeding, it’s a good idea to keep an eye out for stray plants and completely remove unwanted seedlings by hand to keep them under control.

Considerations

• Fountain grass and pampas grass aren’t for every yard, however. Both plants produce a great deal of seed that can quickly spread over a wide area. In fact, pampas grass is classified as a pest plant in California and is listed as a noxious weed in Hawaii. The invasive nature of these plants can be controlled by cutting back plumes before they go to seed and quickly removing any unwanted seedlings. Both plants dry out in the autumn and winter, making them very flammable and therefore not recommended for planting close to buildings in wildfire-prone areas. The leaves of pampas grass also have sharp edges so it’s a good idea to plant them in out-of-the-way locations, and always wear gloves and protective clothing when working in and around the plants.