Q&A - Birch Tunnel

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Last week, Brooke left a very nice comment and a couple of good questions:

I am in love with the birch tree tunnel -- how beautiful! What type of birch trees are those? What is the system that is holding them up? How would one go about replicating this amazing design?

The trees are good old Betula jacquemontii, or Whitebarked Himilayan Birch, a fairly common landscape tree in our area.  In this shadier area of the garden, we wanted the trunks of the trees to stand out, and this birch had both the eye-catching light bark and the tolerance for cool, moist (but well-drained) soils that we needed.  We should note that this is the first time we've used this tree for this application, so it isn't yet "proven," but, as you can see, so far so good!

The structures are round steel tubes that we had bent to a specified radius.  Believe it or not, there are shops dedicated just to bending metal!  If you wanted to replicate an arch like this, you can talk to a pipe bending company or you may have better luck a local metalworker who can oversee the project for you (most pipe benders are not accustomed to working with homeowners).  Alternately, you may be able to carefully fabricate a supporting structure from a smaller diameter metal, such as rebar, but it is very difficult to get and keep a perfect curve and straight sides.  No matter what your method, be sure to make the "legs" of your arch extra long, in order to sink them below grade in concrete.

Design-wise, this is obviously not a new concept.  For centuries, landscape designers have understood the power of focusing attention with geometry, and our take on the allee is nothing new.  When considering a feature with this aesthetic weight, it is vital to get your lines just right.  Make sure your "tunnel" is straight and centered, and carefully consider the views or focal points at the ends.

This is our only allee, but the balance of soft and hard lines in a metal arch can create a striking effect in many spaces.  Below are a couple more photos of arches we have created.  If you missed it, you can get another view of the arches in our last post.

Thanks for the questions, Brooke!