22.05.2018 | ...makes for a tidy garden

Swiss larch...

The larch is a tree native to Switzerland's forests. It grows especially well at altitudes over 1,400 metres above sea level, especially in the mountain valleys of the cantons of Ticino, Valais and Grisons. It’s no surprise that the Axpo subsidiary, Tegra, located in the Canton of Grisons, came up with a clever idea: Processing larch bark for garden use.

Larch wood is one of the heaviest and hardest among European conifers and robust against the weather. The tree’s wood is mainly used to make furniture or interior carpentry, and for the construction of buildings and bridges. The focus is on using the wood, but not the bark. However, larch bark has potential. Axpo identified this potential and for nearly a year Tegra in Domat/Ems has been transforming this bark into an attractive, high quality garden covering.

Multiple uses for shredded larch bark in gardens.

Tidy and sustainable

Spring and fall is the time when shredded larch bark is in demand by hobby and professional gardeners. It can be used as a decorative element in gardens and on paths, and as a ground covering. The bark can be used to separate plants or make paths between planting beds. The covering is an attractive highlight together with colourful plants and inhibits the growth of weeds. As such, there is no need for chemicals to prevent weed proliferation.

How the tree got its name

The root comes from Larix. This is how the ancient Gauls referred to this unusual tree that changes its colour from fresh green in spring to bright gold in the fall before dropping its needles. From the Old High German words "Laihta", "Larihha", or "Lericha", to"Larche" or "Lerche" in Middle High German, it ultimately became known as "Lärche" with an "ä" to distinguish it from a bird with the same sounding name, the “Lerche” (lark).

The larch cones can be green, red or purple.

The larch is a green conifer and drops its needles in the late fall. During the winter the tree is bare.

Manufacture

The bark is removed from the larch trunks in the forest or at the saw mill. The majority of the wood comes from the Canton of Grisons where there is a high larch population.

Axpo Tegra buys the bark and transports it to Domat/Ems by lorry. At the plant the larch bark is placed in containers where it undergoes a state-of-the-art drying process over three to four days until the product has a maximum moisture content of 18 %. After the drying process the material is sifted to a grain size of 25 - 40 mm and larger pieces are reduced to this size. Compared to conventional, non-dried garden coverings, Tegra larch chips keep longer, are neutral in odour, and easier to transport. After processing, Axpo sells the shredded bark to a distributor. The distributor packages and sells the product in the retail sector.

Half a year of power for the city of Chur

In addition to wood chip processing, Axpo Tegra also produces power: Tegra is the main customer for energy wood from the forests in the Canton of Grisons. This makes an important contribution to forest management, forest conservation, and the reduction of natural catastrophes. The construction of the wood chip drying plant in 2016 enabled the wood-fired power plant in Domat/Ems to increase its production so that Axpo Tegra AG can accept a large volume of wood from the Canton of Grisons and neighbouring regions. Some 220,000 tonnes of wood are used for energy production per year. The wood-fired power plant can generate enough power to supply the city of Chur with electricity for half a year.

Axpo Tegra AG

Axpo Tegra AG operates Switzerland's largest biomass power plant in Domat/Ems. The eco-friendly wood-fired power plant uses wood chips from forest, field and garden waste wood. In addition to power, hot steam is generated as process heat. Thanks to this steam, Ems-Chemie AG was able reduce its CO2 emissions by 85 per cent. In addition to 25 of its own and some 60 positions in partner companies, Axpo Tegra AG generates a yearly value-added amounting to CHF 21.5 million. Some 85 jobs are connected with Axpo Tegra directly in its wood-fired power plant and indirectly in forest management as well as the transport industry.

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