Pampas Grasses: One a Weed and One a Garden Queen

With tamarix and Scotch broom, jubata grass (Cortaderia jubata) is proving an unwelcome, ill-behaved guest, shouldering out native plants as it colonizes large areas where nothing checks its spread.
Pampas grass (Cortaderia selloana), a plume grass from the pampas of Argentina, Bra­zil, and Chile, has been a popular specimen plant in temperate gardens of the western United States since the middle of the nineteenth century. Several decades ago, a surrogate species, Cortaderia jubata, was introduced to the trade and has since become a primary weed in coastal areas of the West. To distinguish between the two, this plant is called jubata grass or Andean pampas grass.

Many nursery people are unaware of the difference between the two plants, and some even favor the weedy species for its rapid growth from seed and its ability to be brought into flower in one-gallon cans over a single season. The gallon-sized plant appears smaller and more suited to small landscapes, but soon becomes much larger. When grown commercially for plumes, pampas grass is planted on ten-foot centers in rows sixteen feet apart.

In north coastal areas where forestry is dominant jubata grass at first was welco...