This grower is sure of this plant identification.
Pennisetum macrourum is also known as African feather grass, it forms neat mounds of green foliage with many arching stems topped with long, slender, cylindrical, softly bristly, white spikes during summer.
Full grown height 1 - 1.50 m
Full grown width 75 - 100 cm
Pennisetum genus (Fountain grass). This genus has about 120 species of tuft-forming, rhizomatous or stoloniferous, annual or perennial grasses. They are grown for their dense flower clusters of brush-like spikelets, they appear in the summer and autumn.
They are very frost hardy. and will prefer full sun with fertile, well-drained soil.