Winterberry � a Minnesota Plant for the Holly-Days

 by

Stephen G. Saupe, Ph.D.
College of St. Benedict/St. John's University
Biology Department
(originally published in Sagatagan Seasons, Winter 2001) 

It will soon be time to deck the halls with boughs of holly.  Worldwide, there are at least 150 species of holly in the genus, Ilex (family Aquifoliaceae). Of these, the ones most commonly associated with the Christmas season are American holly (Ilex opaca ) and European holly (Ilex aquifolium).  Like most other species in the genus, these plants are small trees with evergreen leaves bearing sharp spines along the margins.  They produce male and female flowers borne on separate plants.  Beautiful clusters of bright-red berries on the female plants more than compensate for the inconspicuous creamy-white flowers.  These characteristics of the holly � small trees, evergreen leaves, spines, and red berries � each feature prominently in the many Christmas legends about holly. 

Holly has long been associated with the Christmas season.  The Druids, Romans and early Christians all adopted holly to celebrate their winter festivals.  In fact, the plant was so revered that it was called the 'holy tree' and eventually �holly.�  A Christian legend suggests that the plant was at one time deciduous but miraculously grew leaves to hide the holy family from Herod's soldiers.  Ever since, holly has been evergreen. This feature even gives the genus its name � Ilex is Latin for an evergreen oak � and is one of the main reasons that the plant was adopted for winter celebrations.  It surely must have seemed a miracle that holly could maintain its leaves throughout the winter season while the leaves of most other plants with which it grew turned brown and shriveled up. 

Another feature of the leaves is featured prominently in a famous old English Christmas carol � "The holly and the ivy / When they are both full grown, / Of all the trees that are in the wood, / The holly bears the crown."  And, from another verse:  "The holly bears a prickle / As sharp as any thorn / And Mary bore sweet Jesus Christ / On Christmas day in the morn."  The holly never intended for these spiny leaves to be used to make the crown that tormented Jesus.  Rather, they evolved to protect the leaves from hungry herbivores especially since they are green and advertising that "supper's on" at a time when there's not too much other available browse.  Interestingly, the upper leaves of the tree beyond the reach of most grazers have only a single thorn on the end.  

Another verse from the "Holly and the Ivy" relates:  "The holly bears a berry/ As red as any blood / And Mary bore sweet Jesus Christ / To do poor sinners good.�  Legends suggest that the berries were once white or yellow and turned red when they became stained with Christ's blood.  Another story says that holly sprung up under the footsteps of Christ.  The spiny leaves symbolized the crown of thorns and the red berries once again symbolizing the blood of the suffering Christ.  

If you want some holly to decorate your home during Christmas you won't be able to find any in the St. John's Arboretum.  The evergreen species of holly (I. opaca, I. aquifolium) only grow where the winters are relatively mild.  You'll have to visit a floral shop to purchase your holly that was probably grown in the Pacific Northwest, somewhere along the coast from Oregon to British Columbia. 

 Although no evergreen holly grows in our area, we are lucky to have one particularly beautiful member of this family, Ilex verticillata � the winterberry (or Black alder) � growing in the St. John's Arboretum.  One big difference between winterberry and Christmas holly is that winterberry is deciduous.  They prefer wet areas and you will find some if you walk along the wetland/boardwalk trail.  Look for medium-sized shrubs around the margins of the ponds.  They have alternate leaves with saw-toothed edges and a very distinctive pattern of veins where the outermost veins are connected in an irregular oval shape near the margin of the leaf.  Like their Christmas relatives, the female winterberry bears bright-red berries in clusters at the base of the leaves.  These dazzling fruits will persist through the winter until the birds remove them; but until that happens, the berries will alert you that you�ve found our Minnesota holly. 

 Winterberry grows in the eastern half of Minnesota, from Iowa to Canada, but is absent in our western prairie areas.  Winterberry makes an excellent landscape shrub so long as you provide them with adequate moisture � they prefer moist to wet organic soil, slightly acidic.  They aren't finicky about sun and will grow in full sun to partial shade. Because winterberry plants are unisexual you will need to plant about one male for every 3 �5 females to insure berry production.  To get an idea of what these lovely plants look like in the landscape, there is a row of winterberry planted along the roadway that runs toward the football field behind the McNeely Spectrum. 

 Not too long a faculty colleague brought to me a sprig of winterberry he had found in the Arboretum and wanted to confirm its identity.  The twigs were full of red berries. According one legend, we are in for a severe winter when the winterberry berries are plentiful.  I'm not too worried because whenever I see this beautiful plant it reminds me of the holidays and always warms my soul.