Tree of the Month - Larch or Tamarack
Larch or Tamarack • Larix laricina
by: Gilbert A Smith, ISA certified Master Arborist
Larch Branches in Summer; Photos by Lesley Bruce Smith
The scrappy Larch Tree has lived in Illinois since the glaciers retreated 6000 years ago. Like a living museum a small remnant of plants survive in Volo Bog about 40 miles NW of Chicago. You’ll find the Larch trees on an island of peaty soil floating on the surface of the bog. If you're there on a stormy day you can actually feel the whole land mass move or “quake” because it’s floating.
Larch in it’s winter dress
The Tamarack grows naturally in the frozen north of Wisconsin, Minnesota, Canada and Alaska and it can be planted throughout Illinois but only at Volo Bog does it successfully reseed itself. The acid soils created by anaerobic (without oxygen) decomposition break the seed coat allowing the Larch seeds to germinate. Also, surprisingly, the peat mat floating on the bog is well drained and that is the perfect root environment for the Larch. The fertile farm fields all around Volo Bog support the world’s most productive agriculture but not the Larch tree because the soil is just the opposite of the bog, alkaline and poorly drained. This kind of contrast is exciting (at least to an arborist) because it points out to us why trees grow where they grow. It helps us see what is healthy for a tree and what is not.
Larch in the later spring
A medium sized tree about 40 feet tall and 20 feet wide, the Larch has many coping mechanisms to survive in Ice Age conditions. Like other conifers the leaves (needles) are compact, limiting the surface area exposed to cold winds and they have thick cuticles for protection. The resins in their sap are a natural antifreeze and the vascular system is discontinuous which makes it more freeze resistant than deciduous trees. The Larch has another trick up its sleeve for surviving really tough winters. In the spring the soft, lime green needles pop out in little explosions along the stem. All summer they clothe the branches in delicious dark lime almost fern like texture. In the fall the lime turns to a golden yellow, then a tawny orange and finally brown before, much to our surprise they fall off, leaving the branches bare. What the heck you think, they have cones and needles, shouldn’t they be evergreens? Those tricky Tamarack know how to survive in arctic cold, they dump their needles just like the deciduous trees.
A great tree for sunny, tough conditions as long as you plant it 12 inches above our clay soil and surround it with a 12 foot wide by 1 foot deep peat moss mulch island. You can under plant it with Pitcher Plant, Ferns, Cranberry and Blueberries which generally grow only in New England. The Larch Tree has been a resident of Illinois since roughly the Bronze Age, and with such a long changing history I wonder how long it will live in Volo Bog and what further climate changes will it see?