Growing Guide For Miscanthus
A long term warm Game cover that will grow consistently to 8ft tall+
Miscanthus can last in excess of 15 years. This is a major advantage over many other game cover crops. It reduces annual costs and field work compared to crops such as maize.
Planting the crop
It is established by planting rhizomes (small parts of the root system which vary between the size of your finger and the size of your fist) into a well prepared seed-bed during the mid March – mid May period. It is important to plant the crop into a fine moist seedbed to ensure that there is good root to soil contact at a depth of 10-15 cm. Planting is normally done by hand for very small areas or by a modified potato planter or specialised planting machine for larger areas. The rhizomes are the major cost of establishment and therefore good quality rhizomes should be purchased from a reputable source.
It is essential that the root stock are lifted from young vigorous crops (2-4 years of age) during early spring and that the management of the rhizomes between harvesting and planting keeps them in a good condition so that they maintain their viability. We have been harvesting and selling rhizomes for the last six years and have researched these factors to help improve establishment results.
Choice of site
The crop can be grown on a wide range of free draining soil types, from sands through to clay, but generally the heavier the soil type, the more difficult it will be to get a fine moist seedbed and the crop will establish poorly if planted into dry clods of soil with little or no tilth. Prior to planting a soil sample to check for acidity (pH), phosphate and potash deficiencies is recommended as this will also indicate the level and type of fertiliser to be applied for the establishment year. If no soil result is available then an application of 375 kg/ha (3cwts/acre) of a 17:17:17 or similar compound should be applied to the emerging crop. Following the first growing season no further fertiliser will be required as the plant has the ability to move the majority of nutrients back into the rooting system during the autumn period.
The plants will emerge over a 3-6 week period and at emergence they are susceptible to being grazed by rabbits and hares and persistent grazing can kill the plants. When crops are planted in long thin strips, as is often the case with game cover crops, this can exaggerate the problem and if grazing pressure is evident then either rabbit proof fencing can be erected or the grazing animals controlled.
Weed control in the first season is important with a weed free seedbed giving the best possible start. There are several cereal and maize herbicides that can be applied post emergence to kill a wide spectrum of weeds. As Miscanthus is a grass crop it will be grass weeds that are the most difficult to control. However if difficult grass weeds, including couch, do emerge in the crop then it is possible to control these with the application of glyphosate at 4 litres/ha in early spring the year after planting whilst the crop is in its dormant state. If the new shoots have started to emerge, normally from early-mid April on wards, then it is too late to apply the glyphosate. After the second year the leaves that fall off the plants following frosts during the winter months will create a layer of mulch that prevents any further weeds from growing therefore no further weed control should be necessary.
The Miscanthus plants will grow to about waist height with approximately 3-4 shoots in the planting season and will provide cover and shelter for the game birds. The crop should then be topped at the end of the shooting season in February-March to help thicken up for the following season. In year two it will emerge from mid April and reach head height by the middle of August with approximately 12-15 shoots per plant. Year three should see the crop reach 8-10 feet tall with up to 50 canes per plant. It is at this stage that the crop is capable of yielding over 10 tonnes of straw/ha when cut and baled in late March or April. The crop has very good standing power and only heavy snow will bend the canes over and even then it tends to stand upright again when the snow melts. This straw is suitable for burning to produce heat and power or can be chopped and used for livestock bedding. This is a second advantage over maize game crops as it provides a crop that that potentially has a cash value with current prices of £40-£50/tonne being quoted.
Miscanthus is a good crop for holding pheasants and it can provide the warmth that is necessary when compared with open mature woodlands. It does not have the feed source that maize can provide but nor does it attract rats and other vermin. If crops are grown in large blocks (over 8 hectares) for commercial reasons it has been reported that in mature thick crops it can be difficult to drive the birds out and there is the possibility that they will try to fly back into the crop behind the beaters. If this is the case then rides can be cut through the crop in late November-December with no real detriment to the growth of the crop in the following season. Once established it is a very low cost crop to maintain with no fertiliser or pest, weed and disease control required. This makes it a very carbon friendly crop to grow.
Miscanthus Cane Yields
The number of rhizomes purchased for planting may be dependant upon the intended end use of the Miscanthus canes. To obtain optimum yields of canes a population of 15,000 plants/ha (6,000/acre) is recommended. Research suggests that cane yields from the optimum density should be in excess of 12 tonnes/ha between years 4 and 15 and it is too early to say at what age the yield begins to decline However some growers are choosing a density of 10,000 plants/ha (4,000/acre) to help reduce the establishment cost. This is acceptable providing soil conditions are good and establishment rates are above 70% but yields of cane will be lower in the yield building phase between years 3-6 of growing the crop.