Pampas grass, the most spectacular of perennial grasses

7 february 2021 - Long leaves grouped together in rosettes, in the centre of which emerge stems ending in magnificent plumes: such is the grass of the pampas. Portrait of the most majestic of the perennial grasses.

Pampas grass, the most spectacular of perennial grasses

A perennial herbaceous plant of the Poaceae family, which includes plants such as wheat, barley, bamboo and grasses in general, Pampas Grass takes its name from the vast Argentine meadows in which it grows naturally. This immense grass, more scientifically known as Gynerium or Cortaderia selloana, to be related to the Spanish word "cortadera", which means "cutting", in reference to the sharp margins of its leaves, comprises around twenty species. A great classic of gardens in the 70s and 80s, it very quickly colonised certain regions, particularly the Breton coast, where it is one of the invasive plants.

Robust as well as aesthetic

The pampas grass, installed as a solitary subject or in the company of other grasses, brings softness and height to a spacious lawn. It is characterised by its extremely rapid growth, imposing dimensions and does not go unnoticed during flowering, from autumn to winter. In fact, dozens of giant, silky plumes (more or less forty centimetres) of creamy white, pinkish-white or slightly purplish pink depending on the cultivar, proudly sway up to almost three metres high. The inflorescences, which are denser and wider on the female feet, are moreover widely used in the making of dry bouquets. It should be noted that the taxon (genus) is considered to be gynodioic, i.e. there are female and hermaphrodite individuals.

Some cultivars

The cultivars marketed of Cortaderia selloana differ in their size, the colour of the plumes and the colour of the leaves.

In the category of the smaller "Splendid Star" varieties, silvery-white plumes do not exceed one metre twenty when in flower. The narrow strip-shaped leaves are creamy yellow with thin green stripes. "Albolineata", creamy-white plumes, occurs in two-metre tufts with variegated leaves with yellow edges. "Aureolineata" belongs to the large size variety (from two to three metres). The plumes are creamy-white, the leaves are a beautiful clear green with yellow stripes. In the same category, "Sunningdale Silver" has very bushy silvery feathers. The leaves, which can be up to three metres long, are a beautiful bluish-green colour.

Cultivation and care

In terms of care, pampas grass is not particularly demanding. While it prefers rather cool and rich soils, when well established it is able to adapt to many situations, both dry and cold. Most varieties are hardy down to minus 15 degrees.

A small ecological warning: it is advisable to cut the inflorescences before dispersal, to minimise the risk of propagation. Seeds can be spread by wind within a radius of more than twenty-five kilometres. This is why pampas grass is considered an invasive plant in all Atlantic and Mediterranean regions, or those with a mild climate, where its spread is noted, and as such it is seen as a threat to biodiversity. On the other hand, even though there are varieties that are more difficult to multiply than others, it is recommended that the growth of this ornamental grass, which spreads rather easily, be contained. 

by Denise Filippi

Article published in the Magazine immobilier.ch of February 2020