Fall Color in Conifers

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Over the past several weeks, our fall color has peaked here in central Illinois.  The stunning bright red to pink hues of red maple (Acer rubrum) were exceptional this year.  Who could miss the rainbow of color from sweet gums (Liquidambar styraciflua), covering yellows to orange-red and even purple, sometimes all on the same tree.  Beauty like this helps us overlook those pesky gumballs that sweetgum will deliver next spring.  Our State Tree, the white oak (Quercus alba), was especially beautiful this year with a seemingly larger red color among its typically orange-brown fall canopy of leaves.  Across central Illinois, the fall superstar of the oak family, swamp white oak (Quercus bicolor), was at its usual best with colors ranging from purple to bright red or orange as fall progressed. 

Broadleaved, deciduous trees are the major constituents of fall color in our forest canopies.  However, some conifers do have unique fall beauty to offer and they are often overlooked for this valuable attribute of their needles (or leaves).  Conifers are defined as cone-bearing trees or shrubs of the order Pinales with needle-like or scale-like leaves.  Contrary to popular belief, not all conifers are evergreen. Several species that grow in our area are actually deciduous and lose their needles before winter.

Eastern white pine (Pinus strobus), which is native to northern Illinois but planted throughout the state, is one such specimen of the order Pinales that has quite beautiful fall color.  However, this fall color is not entirely conspicuous as it presents itself on inner needles. 

In spring, white pine grows a new set of needles at the growing tips of each limb.  You have probably noticed the interesting, oddly green-colored new growth in spring at the branch tips, often referred to as “candles”.  In fall, needles that are 3 years old, which were the new growth in years past, are shed.  This creates an interesting arrangement of bright yellow needles located toward the interior of limbs.  When contrasted with the blue-green of the existing 1 and 2 yr old needles on the branch tips, it creates an exquisite fall display for a few weeks, typically earlier in the fall season, but somewhat variable based upon our summer weather and individual tree health.

Interestingly, all evergreen conifers shed older, inner needles in fall.  Due to the smaller size of some needles, more vigorous growth on the branch tips or intricate branching patterns, this fall color is less visible on most species.  White pine has a unique combination of a spacious branching pattern, longer needles and brighter yellow fall color which create such a showy display.  

Another quite spectacular fall display can be observed on eastern larch (Larix laricina), also referred to as tamarak.  This interesting species is native to some of our northern counties around Lake Michigan, but barely hardy in our area as it abhors heat.  It prefers bogs or swamps, making it tolerant to a wide variety of soil conditions.  One the most fascinating aspects of this tree that it is deciduous.  That’s right, it’s a conifer that loses all of its leaves (or needles) each year.  In addition, it lights up the autumn landscape with a spectacular neon yellow to gold fall display. 

One of my all-time favorite trees, in urban and natural settings, is the bald cypress (Taxodium distichum). It is native to some of our southern counties, preferring poorly drained bottomland forests, but has been planted throughout the state in a variety of conditions.  In fall, it turns an absolutely magnificent, glowing orange color and holds this display far longer than other trees, providing the best fall color of any conifer in our region.  Many cypress trees are still in full fall color right now or haven’t quite changed. 

Beyond the fall beauty, this tree offers a light green, airy and feather-like summer foliage that compliments most landscapes.  It is a deciduous conifer like eastern larch and in winter it adorns attractive, fibrous reddish brown to gray bark.  This relatively fast growing tree is adapted to an extremely wide range of soil conditions, making it both drought and flood tolerant. 

In addition, bald cypress is relatively insect and disease free.  It is one of the best performing trees in urban settings due to the wide range of site conditions it tolerates, making it hard to beat when it comes to 4-season beauty and survivability.