The larches (Larix spp.) are unusual conifers, in that they are deciduous
and drop all their leaves each autumn, unlike their evergreen cousins. They are among
the earliest trees to come into leaf in spring, with leaves on both
short shoots (spurs) and long shoots. Clusters of leaves arise from each spur.
The needle-like leaves are usually vivid green, sometimes blue-green in summer
and turn butter yellow to old gold in autumn. Upright, summer-ripening cones are
borne on the shorter shoots, and remain on the tree for some time. In older
trees the branches tend to droop in a graceful manner.
Larches are adaptable to most soils, though wet soils are best avoided for
most species. All need full sun, and are readily transplanted when dormant. Species hybridize readily, in the wild
and in cultivation. They propagate readily from seed.
Larix occurs in boreal circumpolar lowlands in Alaska, Canada and Russia, and at moderate to high altitudes in the mountains of North America, northern Europe, and over much of Asia from Siberia as far south as northern Myanmar. There are about 11 species (there is some debate about the Asian ones). The most commonly available larch for landscaping is the European larch or hybrids of this species.
The European larch, Larix decidua (= europaea) is hardy to zone 2. In its native range in the Alps and Caucasian mountains, it forms extensive forests at high altitudes. It has also naturalized in other parts of northern Europe on moist soils in temperate regions. This tree was important in European folklore, being traditionally considered to prevent enchantment and ward off evil spirits – infant children sometimes wore collars of larch bark as protection against the evil eye. Various preparations of larch were also used for medicinal purposes. In European folk medicine, the resin was taken internally to cure tapeworm, bloody diarrhea, and suppress menstruation, and externally, it was applied to wounds, sores, and other skin problems. A brown dye was also obtained from the needles in autumn.


On
the North American continent it is most commonly found in southeastern Canada
and the northeastern United States, and makes a great ornamental tree. Young
trees establish very quickly and grow vigorously, putting on 12 to 18 inches of
growth annually. This large, graceful conifer will grow from 70 to100 feet tall
and can attain a diameter up to 2 feet. It grows with a straight trunk and an
open crown, becoming pyramid shaped with age. The conical crown becomes broader
as the tree matures, with some wide-spreading horizontal as well as erect
branches.
Leaves emerge a tender light green in very early spring, and deepen to a medium green by summer. They turn a rich yellow color before shedding late in the fall. The dropped needles form a soft mulch under the tree.
It bears small,
egg-shaped, upright, persistent cones. The cones start out a somewhat showy
pinkish-purple and mature to softly woody brown cones the first year. Many
trees retain dead cones for ten years or more. Unlike the other large-coned
larch species, European larch cones have scales that are straight or
slightly incurved at the tips, rather than open or reflexed.
The
bark is greenish grey-brown and smooth at first, but becomes fissured vertically
on older trees. The trunk becomes pink-brown with deep, broad, scaly ridges.
European larch does best with sufficient moisture, well-drained and sunny conditions; it does not grow well in very dry or wet soils.
There are a few cultivars of European larch, including 'Corley,' which makes a
dwarf spreading tree, and
‘Pendula,’ a small version of the original that weeps down to the ground. In
addition to these and other cultivars are hybrids such as
Larix x marschlinsii (Dunkeld larch), a natural hybrid between L. decidua and L. kaempferi
that was first raised on the estate
of the Duke of Athol at Dunkeld, in Scotland, in 1904. Intermediate between its parents, its differs only in the yellow,
slightly waxy-bloomed shoots and conical cones. 'Varied Directions' has
pendulous branches. Larix x pendula, a hybrid between L. decidua and L. laricina is very
similar to L. decidua. This cross has also given rise to at least a couple
of garden forms that are quite distinctive plants. 'Contorta' has twisted young
branches and 'Repens' is a spreading ground cover that is very attractive when
its foliage turns gold in autumn.
Other species of larch that are not generally available for horticultural use include:
– Susan Mahr, University of Wisconsin