I Planted ...What???

For a long time I’ve wondered why the great interest in exotic barberries and no mention of our native species, American barberry, Berberis canadensis.  From the design standpoint, Japanese barberry offers a wide variety of foliage colors and forms while, as it stands today, there is only the native form of B. canadensis available.  Of course the Japanese barberry, B. thunbergii, we see today is the result of much work in the horticultural field to develop all those unique forms.  This widespread use of Japanese barberry in the landscape has led to its spread into the wild.  Birds do like the red berries and deposit them throughout the landscape through their droppings.  Once established in the wild it is able to out-compete native vegetation as it is rarely browsed by deer.  Instead the deer turn to native vegetation, in many cases severely decimating the native plant populations.  Japanese barberry has also been associated with the spread of Lyme disease due to its tendency to harbor ticks.

This American barberry was planted in early spring
and has more than doubled in size since then.

 

Identifying features of American barberry are the
 three-pronged thorns and the teeth or bristles
on the leaf margins as indicted by the arrows.

American barberry, B. canadensis, is a mounding shrub growing from 2 to 6’ tall that can spread via underground stems.  It has 1-2 inch long spatulate leaves with widely toothed margins.  Its thorns are three pronged, which differentiates it from the single pronged Japanese barberry.  In the spring it bears drooping clusters of yellow flowers.  The flowers give way to red, edible fruits in late summer to early fall.  One concern with American barberry is that it is an alternate host for black stem fungus (rust) in wheat.  (European barberry, B. vulgaris, is the major offender which led to its near total eradication in wheat farming areas.  Japanese barberry does not act as a host for this disease.)  However this is not as significant of a problem within its native range south from PA to GA.  Native habitats include savannah and open woodlands, but these areas are decreasing due, in part, to fire suppression leading to increases in shade.  Some gardening sources indicate that American barberry will grow under a variety of conditions, in the wild it favors shallow, neutral to basic soils.

The reason I wanted to try now American barberry is as a replacement for Asian spireas.  In particular I’m looking for a mounding shrub that blooms in the summer and grows 3-4’ tall.  I would also expect that this barberry would be resistant to browsing by deer, but that is not confirmed.  I'm also looking at NJ Tea, Ceonanthus americana, as possible spirea substitutes.  More on that later.

I found this Eastern Wahoo growing in Beaver Brook Reservation
 in Belmont, MA.  The inset shows the deeply furrowed bark which
 appeared to take on a diamond-like pattern.

 The other new plant that I got this spring is Eastern Wahoo, Euonymus atropurpureus. It is a small tree or large shrub native to the eastern U.S.  I have generally been in the business of ripping out Euonymus species whenever I saw them.  This has applied particularly to burning bush, E. alatus, and wintercreeper, E. fortunii, both invasive species.  A number of years ago I came across an Eastern wahoo growing in an unmanaged suburban woodland in the Boston area.  The bright colored seed pods in fall and the diamond patterned bark were two attributes that sparked my interest.  What I found may have been a garden escapee since it is not native to the New England states. Its native range is primarily in the Mid-West; however, it does extend into parts of Maryland, as well as Pennsylvania, Virginia and West Virginia.  So when I saw that it was available at a regional native plant nursery I decided to give them a go.  It is quite shade tolerant so I put them in an area where I have been removing established tree of heaven, Ailanthus altissima, as well as seedlings of burning bush.

This photo, taken in early November, shows that Wahoo holds onto its leaves
fairly late into the year.  Most of the red arils have fallen from the flowers. 

One of the tricky aspects of planting eastern wahoo, while actively removing winged euonymus seedlings is that I will need to tell them apart, lest I remove a desirable plant.  The obvious thing is to make sure that I keep a recognizable tag on the wahoo and remember where they are planted.  Comparing young wahoo to burning bush seedlings show both to have some corkiness, but the Wahoo has it in straight lines and it is not as pronounced as on burning bush.  Also, the leaves of burning bush are stiffer and more narrow and pointed than those on a young wahoo. 

Here's a comparison of an existing burning bush (left) with
 an Eastern Wahoo seedling (right).