Site Selection

When considering a site for planting, thought should be given to the site’s ecological and historical value, and the visual impact of the crop on the landscape because Miscanthus grows taller than arable crops. Public access and machinery access for planters and harvesters should be taken into account in plantation design.

Miscanthus produces a reasonable yield from most soil types but the optimal is pH 5.5-7.5 and Magnesian (or Calcium) limestone may be applied to the soil in the first year if necessary. The site should not be in an area with particularly waterlogged soil as the crop is harvested in the winter and wet ground would restrict machinery access, the use of heavy machinery in these conditions may also cause soil compaction which would hinder root growth.

Ground Preparation

The quality of site preparation is vital to the establishment of the crops and its subsequent ease of management. Preparation should begin in the autumn before planting, starting with the application of an appropriate broad-spectrum systemic herbicide (e.g. glyphosate) to control any perennial weeds present. The area should then be ploughed and allowed to over winter when frost activity will break down the soil further. Immediately before planting in the following spring the site should be rotivated to produce the fine tilth required for root establishment.

Planting Material

Planting material is produced from two or three-year-old plant rhizomes (roots) split into pieces using a rotary cultivator. The rhizome pieces can be re-planted to produce new plants, but must preferably have at least 2-3 ‘buds’. The rhizomes can be stored in cold- storage (<4 °C) for up to a year, though storage in heaps in the field for a short period covered in moist soil is acceptable. Best results are obtained if rhizomes are replanted within 24 hours of harvesting.

Planting Methods

Rhizomes should be planted in early spring (March-April) when soil moisture content is high, at a soil depth of 5-10 cm. The optimal density is 20,000 to the hectare. (Full establishment will take 3-4 years). For a high percentage establishment, the rhizomes should ideally be planted using semi-automatic potato planters. The potato planter requires planting material to be sorted to <10 cm lengths and the resulting planting density will be dependent on the speed of the land wheel. The planter should be followed with a roller to compact soil ensuring good contact.

Alternatively, miscanthus rhizomes can be broadcast and rolled with a slurry spreader. However, this latter method may decrease the winter survival of rhizomes that remain close to the surface.

Miscanthus does not usually require an addition of fertiliser during its establishment phase and fertilisers may increase weed problems at this stage until the crop achieves canopy closure.