Gardening 101: Pampas Grass

Pampas Grass, Cortaderia selloana

The majestic plumes of perennial pampas grass have inspired poets—and provoked the scorn of environmentalists. For good reason, in both cases.

First, what’s good about pampas grass? The poet Edna St. Vincent Millay bemoaned the cold, dark days of late autumn when the “feathered pampas-grass rides into the wind, like aged warriors westward, tragic, thinned of half their tribe.” In other words, when resilient pampas grass starts to look tired in a landscape, winter is upon us. In other seasons, 13-foot-high clumps wave buoyant snowy plumes and create as much visual interest as any small specimen tree. (One of our favorite examples of this is in magical English garden Saint Timothee.)

What are the drawbacks to pampas grass? The biggest negative: Pampas grass is invasive in some climates, notably on the US West Coast and in Australia and New Zealand, where it is a rampant weed and crowds out native species and tree seedlings. (This behavior does not occur in its native South American environments, where “Cortaderia selloana grows on river plains where part of the year the crown is under water while the rest of the year the plant is stressed by drought,” as Pacific Horticulture notes.)

Not all pampas grass is equally invasive, however. Read on to learn how to tell the difference between “bad” pampas grass and “safe” pampas grass before you plant it in a landscape:

One species of Cortaderia is much more invasive. If you happen to see pampas grass at a plant nursery, run—don’t walk—away from Cortaderia jubata, a weedy species that has none of the good looks of Cortaderia selloana. Jubata grass, which has “harsh, cutting leaves” also has “dun-colored plumes that look like old dishrags on sticks,” according to Pacific Horticulture writer John Madison, is Public Enemy No. 1 on the California Invasive Plant Council’s list.

The plant council also includes C. selloana on the invasive plants list. But experienced horticulturalists can contain it. “C. selloana is a dioecious plant, with male and female flowers on separate plants. The hairs on the ovary fluff up the plumes, making the female plants the desirable horticultural specimens. If only females are planted, there will be no pollen and no seed and the plumes will remain fluffed up for some time,”  writes Madison. “Anyone buying a plant of pampas grass should ascertain beyond all doubt that it is a female plant of C. selloana.”

On a lighter note, pampas grass also has gotten some recent bad press in the UK. Some homeowners have stopped planting it in their front gardens because its presence has become associated suburban sex scandals. How did pampas grass earn an X rating? “Plant sellers says sales have plummeted—in no small part due to the plant being regarded as a secret signal to passersby that its owners are happy to indulge in swinging,” notes the Telegraph. For the record, you can still find dwarf pampas grass among the offerings of more than 4,000 plants from Crocus plant nursery (£14.99 for a 2-liter pot of Cortaderia Selloana ‘Pumila’).

Cheat Sheet

• At heights up to 13 feet and in clumps that are 6 or more feet in diameter, pampas grass is a showstopper that can be planted as a single clump or in small groups—if you to focus visual attention on a specific spot in the garden.
• Dried pampas grass fronds are airy, frothy additions to floral arrangements.
• Cortaderia makes a good companion to other perennial grasses, contrasting in size, texture, and color to create a sense of depth in a landscape. Pampas grass also is an effective backdrop for colorful shrubs such as Red Twig Dogwood.

Keep It Alive

• Pampas grass is a perennial that will survive winters in USDA growing zones 7 to 11 (and is considered marginally hardy in zone 6).
• Plant pampas grass in a sunny spot (with at least six hours a day of sun) and in well-drained soil.
• Space clumps of pampas grass about 8 feet apart to account for their statuesque silhouette at maturity.

Read more growing tips in Pampas Grass: A Field Guide to Planting, Care & Design in our curated guides to Grasses 101. For more ways to use perennial grasses for a painterly effect in the garden, see:

• Before & After: From a Blank Canvas to a Golden Garden in a London Suburb
• Maiden Grass: A Field Guide to Planting, Care & Design
• Gardening 101: How to Care for Perennial Grasses
• Vineyard Haven: A Napa Valley Garden That Belongs to the Land

And look here for ideas in how to decorate with pampas grass indoors.

N.B.: This post has been updated with additional information and links; it was first published on Feb. 1, 2019.