Larix laricina (Du Roi) K.Koch

Tamarack, Larix laricina, is one of the most widely distributed conifers in North America. It occurs across the entire breadth of Canada, in a great, almost un-interrupted swathe from the Yukon to the Atlantic seaboard; it stays well north of the border as far as the Great Lakes region where it plunges south into the United States, finding its southern limit the northern Appalachian mountains. It also has an extensive though disjunct distribution in Alaska. The species is an important component of the boreal and sub-arctic conifer forests that stretch across most of northern Canada, associating throughout with Abies balsamea, Picea glauca, P. mariana, Pinus banksiana, and just a few broadleaves, mainly Betula and Populus (Debreczy & Rácz 2011, and see habitat notes above). Only in the east of the range, where the proximity of the North Atlantic Ocean influences the climate, does this forest become significantly more diverse, with species like Picea rubens and Thuja occidentalis beginning to commonly associate together with an enlarged cast of broadleaves; this is also the part of the range where the species is most likely to form pure stands, albeit locally (Farjon 2017).

As a wild plant Larix laricina favours poorly drained sites including swamps and peat bogs (muskegs), and particularly in the south of its range its tolerance of such conditions gives it a competetive edge over several of its associates (Farjon 2017). It shares this trait with other species distributed in boreal regions (L. sibirica, L. gmelinii, and to a very limited extent L. kaempferi) but L. laricina is perhaps the best adapted of all to wet ground.

The species was an early arrival into Europe, but there is some doubt as to exactly when it was introduced. Like so many other North American trees Larix laricina would likely have been introduced to France during the 18th century, but the revolution swept away records and probably any surviving trees too. Across the English Channel we know that the 2nd Duke of Atholl planted L. laricina at Whitton near Hounslow (modern southwest London) in 1760 (Loudon 1838), but Peter Collinson was growing a North American larch at Peckham in 1739 and in all probability this was Larix laricina (Bean 1981; Mitchell 1972).

Whatever the date of its introduction Larix laricina has never done much to fire the European imagination, and even in its native North America it plays only a minor horticultural role, useful on poorly drained sites but most often overlooked in favour of another species. It has the smallest seed cones in the genus – just 1–2 cm long – which are a rather attractive maroon colour when immature, but this is probably its chief point of interest. Even its autumn colour is somewhat muted compared to other species, at least in Europe (pers. obs.). L. laricina does not reach any great size in cultivation and it has proven rather short-lived: in 1907 Elwes and Henry could not trace any of the trees mentioned by Loudon in 1838; in 1972 Mitchell could not trace any of the trees mentioned by Elwes and Henry, etc. etc.

Indeed, the largest examples in modern UK cultivation were all planted in the relatively recent past. The tallest of all, 20.7 m at Bedgebury National Pinetum, Kent, was planted in 1994, while a 19 m tree at Wakehurst Place, West Sussex, was planted in 1998 (The Tree Register 2026). Trees planted on wet ground are likely to grow very quickly at first, but then slow right down later, while trees on well drained or rich soils are likely to grow slowly and to have poorer form (Mitchell 1972). The species shows little regard for microclimate in the UK and Ireland: it can grow equally well (or equally poorly) in the warm, dry south and east of England as it will in the cool, wet, north west Highlands of Scotland (pers. obs.). Its only requirements, as is the case for all larches, are for a sunny position whilst establishing and an acidic soil.

A few cultivars have been named, mainly in North America and mainly by devotees of dwarf conifers who have selected witches’ brooms, or stunted forms from particularly inauspicious habitats where trees are naturally dwarfed and stunted. None has been widely circulated and we discuss just a few of the most important ones here.