Larix gmelinii

Olga Bay larch is native to North Korea and neighbouring areas where the climate is similar to Finland’s. Fast-growing, hardy, and beautiful, it grows well in southern and central Finland. Unfortunately, it has so far been planted almost solely in scientific collections. Significant characteristics in identifying the species are the slightly upward-growing branches, very short needles and the cones, which are shiny red before ripening.

Mustila has a small plantation of Olga Bay larch on the west side of Etelärinne (Southern Slope), dating from about 1910. The provenance is unknown. A. F. Tigerstedt had noticed their rapid growth and early autumn coloration in the nursery stage, the latter an indicator of hardiness. Now over a century old, they are still beautiful, like slender versions of the European larch (L. decidua).

The natural range of the Kurile larch in eastern Asia includes the Kurile Islands, Sakhalin Island and, according to some interpretations, the Kamchatka Peninsula. The species can be grown at least to central Finland. It is easy to recognise from its long sweeping branches which produce a special feeling in the woods. The brown needles remain on the tree until late autumn, till the snows come.

The Arboretum’s oldest Kurile larches were planted in 1919 on Pohjoisrinne (Northern Slope) and at Lepistö. The biggest plantation, in the western part of the Arboretum at Nokkala, is about 10 years younger. The species seems to grow well in almost any kind of soil. The handsomest stand grows on clay, which is a rich but hard medium.

Of the larch species growing at Mustila the Kurile, together with the European and Siberian larches (L. decidua, L. sibirica), has shown itself the most promising from a forestry standpoint. When young, it grows very fast and at 4 years old is already noticeably larger than the other larches. It quickly achieves logging size if stands are sufficiently thinned.

Dahurian larch is native to the coldest parts of east Siberia, where it forms the world’s northernmost forests on the Taymyr Peninsula, on the shores of the Arctic Ocean. This species even grows in the coldest area in the northern hemisphere, in the Verkhoyansk mountains, where temperatures down to -70C have been recorded. Despite this, it struggles on through dry summers taking advantage of the moisture released by the surface melting of the permafrost. It is assumed to be hardy throughout Finland.

In addition to its hardiness, Dahurian larch has other useful characteristics. In its native habitat it grows into a big tree, up to 35m (135 ft) with a thick trunk. The species hasn’t been planted much in Finland and probably won’t grow here to the same size. At Mustila, for example, trees planted on Pähkinärinne (Hazelnut Slope) between 1910 - 1920 have only achieved 12-18m (40-60 ft) in height. In habit, this tree is conical with long branches growing horizontally. The cones are small, not more than 2 cm.

Though rarely planted, this tree would be suitable for landscaping even in northernmost Finland, where it would probably grow better than in the south, given seed of suitable provenance. It is also adaptable, growing on peat and on packed soil.