Cooperative Living June 2024 - 37

BRANCHING OUT
Black Walnut:
Massive and Messy
The good, the bad and the nutty
by Steve Carroll, Contributing Columnist
Today,
A
landowner with a mature, open-grown
black walnut is fortunate indeed, able to
appreciate this tree's massive presence;
thick, dark, furrowed bark and fl avorful,
black walnut is
valued for its
beautiful
heartwood.
protein-rich nuts in the fall. On the other hand, a
homeowner with a tree whose branches overhang the
sidewalk and driveway - not so fortunate, as they must deal
with fallen leaves and branches; a barrage of walnuts on the
roof, sidewalk and car; and the eff ects of juglone, a chemical
that leaches from walnut parts and interferes with the growth
of nearby plants such as vegetables.
Black walnut (Juglans nigra) is a striking tree, with
brown-black bark, thick twigs and a typically straight trunk.
Leaves are 12 to 24 inches long, with 10 to 24 fi nely toothed
leafl ets that turn yellow in the fall. Th ese leaves drop earlier
than most other hardwoods, and they are slow to leaf out in
the spring. Walnuts are classifi ed with hickories (genus Carya)
in the walnut family.
Black walnut is an eastern species, native from
Massachusetts to the Florida panhandle, and west to South
Dakota and east Texas. It prefers rich soil, moist uplands
and fl oodplains, but also grows along fencerows and in old
fi elds - and anywhere a squirrel has buried a nut. It can
also be planted well outside its natural range.
Male fl owers form in hanging catkins in late spring, with
female fl owers in small clusters at twig ends. Walnuts are wind
pollinated, and if successfully fertilized, fruits mature by the
fall. A newly formed walnut seed is enclosed within a hard,
ridged shell, which itself is surrounded by a yellow-green husk.
Walnut trees typically have both male and female fl owers
and can, therefore, self-pollinate. However, the resulting fruits
may be relatively few or small. Better to plant two or more
trees near each other to encourage cross pollination.
Walnuts are eaten by many birds and mammals, and the
foliage is fed upon by more than 100 moth and butterfl y larvae.
Some Native Americans ate the nuts fresh, boiled, in soups
and as fl our, and they used the husks and roots to make dyes.
Aſt er European settlement, the rot-resistant wood was used
for fenceposts, shingles, railroad ties and mill waterwheels,
and the fruits were, and still are, used to make dye for yarn
and fabric. More recently, the ground shells have been used
as an abrasive in the automotive and airline industries.
Today, above all else, black walnut is valued for its beautiful
co-opliving.com
heartwood, which is widely used in making fi ne furniture,
cabinets, church altars, rifl e stocks and more. Walnut is also
now used to make increasingly thin veneer. Walnut wood is so
valuable that landowners have sometimes planted trees as an
investment for their grandchildren and great-grandchildren.
On the other hand, having trees on your property doesn't
guarantee fi nancial success, as loggers may decline to maneuver
large trees and logs around power lines, fences and buildings.
Woodworkers may also worry that unseen embedded nails,
bullets, pieces of metal fencing or hidden hammock anchors
will damage their extremely expensive saws.
Walnut is relatively free of pests, but the spread of a fungal
infection called thousand cankers disease in the western U.S.
is causing concern.
Do you have black walnuts on your property? Perhaps you
should do as in earlier times and host a fall " nutting party. "
Invite your friends and neighbors over to help shell the fruits,
appreciate the rich, oily taste of the nuts, and prepare a few
pounds of nuts for your winter cooking and baking.
*
Steve Carroll is a botanist and ecologist who speaks and writes
about trees, gardening and the world of plants. He is the co-author
of " Ecology for Gardeners, " published by Timber Press.
June 2024 * Cooperative Living * 35
Black walnut trunk
and canopy
Black walnut leaves
and fruits
PHOTO BY JOHN EVANSON VIA FLICKR
PHOTO BY KATJA SCHULZ VIA FLICKR
PHOTO BY KAREN HINE VIA FLICKR
http://www.co-opliving.com
Cooperative Living June 2024

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