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Plant of the Week
Blackgum, Sourgum, Tupelo
Latin: Nyssa sylvatica
The blackgum is the earliest of our native trees to turn color in the fall, but
it does it slowly over a six-week period. In the beginning, only a few leaves
turn a bright red; but by early October, the tree is a forest standout with its
glossy red leaves glistening in the autumn sun.
The blackgum is a member of a small plant family, the Nyssaceae. The family
includes only three genera important as ornamentals.
The blackgum ranges over most of the eastern states in its various forms,
appearing from the swamps of eastern Maine to the pine thickets of east Texas.
In Arkansas, it’s found statewide in upland and lowland sites, but nowhere does
it form dense stands. It only appears as scattered trees in the forest.
Blackgum grows to 60 feet tall and usually is less than 25 feet across. It
usually has a single, straight trunk with branches that emerge at right angles
like those of pine trees. Young trees are often pyramidal, like a pin oak, while
older trees may be more columnar or round-headed. The ends of the branches are
often droop, giving the tree a distinctive winter silhouette.
Leaves are up to 5 inches long, one third as wide and glossy green on the upper
surface. The tree produces tiny greenish-white flowers high in the branches that
are followed in the fall by blue-black berries about the size of a peanut.
The common names of this tree are a bit of a puzzle because it’s extremely
dry-wooded and doesn’t produce sap, which is required to produce a "gum." Thee
tree has never been used to produce either a sour gum or a black gum, so the
common name is probably due to a bit of botanical confusion among woodsmen.
The name "Tupelo" is an adaptation of the Creek Indian language. They’re the
original inhabitants of Georgia, Florida and Alabama. "Eto" means tree, and
"opelwv" means swamp.
To the lumberman, blackgum is difficult to work with because it has
interconnected grain that runs lengthwise with the tree, but also crosswise,
making splitting almost impossible. This interlocked grain has made the wood
useful for blocks in agricultural equipment where wooden parts that won’t split
are needed. The wood has also been used to make baskets and handles.
A friend who grew up in the backwoods of Arkansas used twigs of the tree as a
natural toothbrush. The wood splinters out in all directions when it’s chewed,
making a little pipestem brush.
As a landscape tree, the blackgum is considered first rate among experts such as
Mike Dirr in Georgia. I like the tree, but I’m disappointed in how slow it
grows. There’s a grove of eight shade tree species that were planted near the
University of Arkansas campus in 1971. After 30 years, the blackgum is only
about half the size of the other trees in the stand. It’s has trunk diameter of
about 8 inches and a height of 30 feet. The oaks, maples and tulip poplar are
all 50-60 feet tall.
Many of our urban landscapes can accommodate a smaller tree more easily than a
mammoth oak, so sourgum does have its place. It does best in good alluvial soil,
but it will tolerate both dry and wet sites once it’s established.
Named cultivars are available that have been selected for fall color and plant
form, but none are readily available from retail nurseries. The tree is best
transplanted from container grown plants. The blackgum is not bothered by
serious insect or disease problems.
By: Gerald Klingaman, retired
Extension Horticulturist
- Ornamentals
Extension News -
September 8, 2000
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