Andropogon gayanus

Cultivation Details

A plant of the tropics and warm subtropics, where it can be found at elevations below 2,000 metres, though mostly below 1,000 metres. It prefers a mean annual rainfall within the range 750 - 1,260mm, but can tolerate 400 - 1,400mm^[1]. It can tolerate up to 2,500mm^[2]. It grows best in areas with seasonal rainfall and a dry season of 3 - 6 months^[1]. The plant is sensitive to lower temperatures; the leaves are killed by frost and growth is restricted where the mean minimum temperature of the coldest month is below 4.4°c^[3]. Optimal flowering is at 25°c^[3]. Grows best in full sun^[1]. Succeeds on a wide range of soils, including those of low fertility, from sands to black cracking clays, but prefers sandy clays of medium to high fertility^[1]. Succeeds in infertile, acid soils, tolerating a pH range from 4 - 7.5^{[1, 3]}. Established plants are drought tolerant and some forms can also tolerate seasonal inundation of the soil^{[1, 3]}. Grown in many areas for pasture, the plant has escaped from cultivation and invaded native areas. It is a vigorous, robust grass which can form dense stands, excluding native species. In the Northern Territory, Australia, it has invaded riparian vegetation (creek banks and flood-plain fringes), degraded areas, roadsides, pastures and Eucalyptus savannah, in areas where annual rainfall exceeds 600 mm^[4]. It has also become naturalized in Brazil^[3]. A highly productive grass that increases fuel loads, cures later than the native annual grasses and produces intense, late dry season fires which seriously damage native woody species^[4]. The plant has three types of roots - most are fibrous roots close to the surface that probably produce the vigorous early growth; thick cord roots which store starch and anchor the tussock; and vertical roots that can extract water at depth during the dry season^[3]. Plants are tolerant of grass fires^[1]. A short-day plant with a critical day length for flowering between 12 and 14 hours^[1].