WOOD EXPLORER by Gene Wengert
wooddoc@uwalumni.com
There are two trees, hackberry (Celtis occidentalis) and sugarberry (Celtis laevigata), that produce the lumber known as hackberry. That is, in the trade that the names hackberry and sugarberry are used interchangeably. Sometimes the lumber from
these species is called sugar hackberry. We will
use the name hackberry here, but will be referring
to both species. The species grows from North
Dakota to Texas to North Carolina to Quebec, but
the Southern states seem to have the best supply.
Trees are often over 100 feet tall, although 75
feet is more common. The berries are edible, but
because they are so high, the birds have their feast
before they can be harvested.
Hackberry is a lumber species that does not
stand on its own too often. Rather, it has been used
as a substitute for red oak, ash or elm. Indeed,
hackberry has strong grain and porous structure,
so it is quite similar to these other three species.
Perhaps the greatest detriment to using hackberry is that it stains (fungal stains and chemical
enzymatic oxidation gray stains) very quickly. Logs
that have been held in warm weather or lumber
that has not been promptly stacked and dried
aggressively right after sawing will almost all have
high staining risk. Careless lumber producers will
produce mostly “paint grade” hackberry because
of the stain. However, with reasonable care,
hackberry is a beautiful wood, worthy of the high
prices paid for the better grades of ash and elm. ;
Processing suggestions
and characteristics
Density. Hackberry has a density of
approximately 35 pounds per cubic foot.
Hackberry KD lumber weighs about 3 pounds per
board foot at 7 percent MC.
Drying. Hackberry wood is very prone to
staining if not handled and dried promptly, including
prompt logging, sawing and stacking. In addition,
using initial temperature in the kiln of 115F with very
low initial humidities also helps to produce lighter
colors. Hackberry has 7 percent shrinkage from green
to 6 percent MC.
Gluing and Machining. Hackberry
glues fairly easily. Prompt gluing within an hour after
ripping is essential to avoid moisture changes in
storage or during delays. The wood machines easily.
If over-dried, chipped grain may be encountered.
Stability. Hackberry has a 1 percent size
change in width (or tangentially) for flatsawn lumber
for each 3. 4 percent MC change and 1 percent
thickness change (radially) for a 6 percent MC
change. The grain is quite straight, so twisting does
not occur and bow and side bend are rare.
Strength. The strength (MOR) at 12 percent
MC is 11,500 psi, the stiffness (MOE) is 1. 19 million
psi, and the hardness is 880 pounds.
Color and Grain. This species is ring
porous. The sapwood is typically pale yellow. The
heartwood, which often is not present, is yellowish
gray or yellowish-brown. The wood can be finished
naturally or it can be stained to closely resemble
oak, ash and elm. It certainly makes fine furniture
and cabinets, but does not get much use as show
wood. As the tv ad says: “Try it; you’ll like it!”
approximately 35 pounds per cubic foot.
Hackberry
+ Want more?
For more on this and other species,
search the Wood Explorer collection at
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Try it, you’ll like it.
