Fagus

The only beech species on the American continent, American beech is common throughout a large range in the east, usually forming mixed broadleaf forests with, among others, sugar maple (Acer saccharum) and yellow birch (Betula alleghaniensis). The smooth grey bark and heavy foliage are reminiscent of its European relative, common beech (F. sylvatica). However, the American species has longer and larger leaves and the trunk is a shade lighter, but the tree itself remains smaller than the European cousin.

Judging by experience at Mustila the American beech can be considered hardier than the European. The lone representative growing on Etelärinne (Southern slope) survived the cold winters of the war years and also those of the 1980s undamaged, while the nearby common beech specimens were severely damaged down to the snow line. American beech is rare in Finland and only a few old individuals are known. Nevertheless their winter hardiness has been so good that the species could be more widely planted in gardens and parks in southern Finland.

Arboretum Mustila expeditions have collected seed from the northern parts of the species’ natural range in 1996 and 2002. The seedlings grown from these collections have grown well in rich shady forest settings but in open lower areas, susceptible to spring ground frosts, they have suffered some damage and grown slowly.‍

There are several named red-leaf varieties of the common or European beech, and the nomenclature can be quite confusing, but typically they include the word “purpurea” in some form or other. These coppery or red leaved varieties are said to have originated from a tree found in Thüringen in Germany in the 1700s, and plants started to appear in nursery catalogues in the early 1800s. They can also be grown from seed, when the colour of the leaves varies; depending on the variety, their redness can remain the same throughout the summer or can almost totally disappear, giving way to green. However, the colour is usually at its showy best when leaves break, and again in autumn before leaf fall.

Copper beech develops into a large tree with a round crown, requiring lots of room and living for perhaps hundreds of years, so it isn’t really suited to small gardens. In Finland it has proved fairly hardy on the south coast, perhaps due to its continental origin.

Mustila’s Alppiruusulaakso (Rhododendron Valley) provides a hint of the feeling in a true beech forest. In the Valley’s warm rich soil and protected by other trees there is a single large beech and a couple of younger trees in much better condition than the specimens on Etelärinne (Southern slope), where they freeze down to snow level in cold winters.

Beeches are at their best in spring, when a magical green light filters through the young leaves, and again in October in their copper and bronze autumn colour. Traditionally, hardy beech provenances have been sought from the northernmost parts of their range in Sweden. But since the 2005 Mustila seed-collecting expedition to Slovakia, the Arboretum has looked for hardy provenances from eastern Europe’s mountain ranges, where the species is known to tolerate temperatures down to -40C in places. ‍