In the Parc de les Rieres d'Horta, as we already mentioned in the previous post, there are many ornamental grasses, mainly from the Poaceae family, such as **_Stipa tenuissima_** , **_Pennisetum alopecuroides_** or Panicum virgatum, which are located along the edges of paths and on slopes.
Grasses, in addition to being very interesting plants throughout the year, thanks to the changing shades of their leaves, are also very useful for soil conservation, thanks to their rhizomatous and deep roots.
This park, created under one of the slopes of the Collserola Natural Park, functions as a green corridor between it and the city's green spaces, which is why grasses are also important since their bearing and foliage favors the creation of protected and hidden spaces highly appreciated by small fauna.
On this occasion we will focus our attention on one of them, Panicum virgatum, a new grass in the Sala Graupera catalog.
Panicum virgatum is commonly known as "switchgrass" in reference to its natural habitat and the plant's distinctive compact and columnar bearing. Native to North America, in the past it covered most of the country's tall prairies. Today it is one of the dominant species of the central region of North America and grows both in riparian areas as well as along communication routes and on the margins of cultivated fields.
It is a perennial plant that can reach 100-125 cm in height and 60-75 cm in width. Its bluish-green leaves are flat, narrow and lanceolate. In autumn they turn yellow, even orange, and in winter they change in tone until reaching light brown. This species has light-colored racemose inflorescences that appear from late summer until well into autumn. Its seeds developed in spikelets are an important food for birds in winter and are also used for decorative purposes both fresh and dried.
It grows well in any type of soil although it prefers moderately moist soils, with sandy or clay texture and can be located in full sun or partial shade. It has tolerance to intense frosts, resisting minimum temperatures down to -15ºC. In any case, it should be noted that if it were planted in a shady position it would end up losing its columnar bearing.
Panicum virgatum does not need extra nutrient inputs; in fact, in very rich soils it will tend to have problems. It is a species that in its natural state prefers moist terrain, but it has great adaptability and tolerates lack of water very well. It is, in short, a very low maintenance plant since normally you only have to remove dry leaves and flowers in spring, although it is also advisable to prune the clump to ground level at the end of winter to renew the foliage. When the groupings become saturated or every 3 to 4 years it is advisable to divide the clump. And it does not show a tendency to suffer from pests or significant diseases.
It is a very suitable species for creating natural gardens. It can be used to create perennial groupings, in screens or borders. It should also be remembered that the characteristics of its root system make it a very useful plant for slope restoration.